- Synthesis of 3-Methylobovatol
-
Biphenyl lignans are rare compounds that exhibit a broad range of biological activities. The first total synthesis of natural biphenyl ether lignan, 3-methylobovatol, has been achieved in four steps. This synthesis allows for modification of the C-2 phenol and in doing so, will facilitate various structure-activity relationship studies into these bioactive compounds.
- Pilkington, Lisa I.,Barker, David
-
-
Read Online
- Magnolol derivative, honokiol derivative, hydrochloride of honokiol derivative, preparation method and application
-
The invention discloses a magnolol derivative, a honokiol derivative, hydrochloride of honokiol derivative, a preparation method and application of the honokiol derivative and the hydrochloride. The magnolol derivative, the honokiol derivative and the hydrochloride of the honokiol derivative have the structure shown in the following formula (I), and by applying the technical scheme provided by theinvention, the magnolol derivative, the honokiol derivative and the hydrochloride of the honokiol derivative are modularly prepared by utilizing a chemical synthesis method, namely a C14 atom markerand a D atom marker, the two compounds can be used for drug metabolism research of magnolol derivatives, honokiol derivatives and hydrochloride thereof. The problems caused by low drug recovery rate in the traditional drug metabolism experiment can be well solved by using the C14 marker, and the processes related to in-vivo absorption, distribution, metabolism and excretion of the drug can be conveniently clarified.
- -
-
Paragraph 0073-0074; 0084-0087
(2021/02/06)
-
- Synthesis and Structural Revision of Glyphaeaside C
-
The iminosugar core of natural glyphaeaside C, originally assigned as a derivative of the piperidine natural product 1-deoxynojirimycin (DNJ), has been revised as a derivative of 2,5-dideoxy-2,5-imino-l-mannitol (l-DMDP) by the total synthesis of its enantiomer. This revised l-DMDP-derived configuration is the first of its kind to be observed in nature. The prepared iminosugars displayed the nanomolar inhibition of bovine liver β-glucosidase and β-galactosidase.
- Byatt, Brendan J.,Kato, Atsushi,Pyne, Stephen G.
-
supporting information
p. 4029 - 4033
(2021/05/29)
-
- Nickel-catalyzed reductive deoxygenation of diverse C-O bond-bearing functional groups
-
We report a catalytic method for the direct deoxygenation of various C-O bond-containing functional groups. Using a Ni(II) pre-catalyst and silane reducing agent, alcohols, epoxides, and ethers are reduced to the corresponding alkane. Unsaturated species including aldehydes and ketones are also deoxygenated via initial formation of an intermediate silylated alcohol. The reaction is chemoselective for C(sp3)-O bonds, leaving amines, anilines, aryl ethers, alkenes, and nitrogen-containing heterocycles untouched. Applications toward catalytic deuteration, benzyl ether deprotection, and the valorization of biomass-derived feedstocks demonstrate some of the practical aspects of this methodology.
- Cook, Adam,MacLean, Haydn,St. Onge, Piers,Newman, Stephen G.
-
p. 13337 - 13347
(2021/11/20)
-
- Structure–Activity Relationship of Anti-malarial Allylpyrocatechol Isolated from Piper betle
-
Malaria disease remains a serious worldwide health problem. In South-East Asia, one of the malaria infection “hot-spots,” medicinal plants such as Piper betle have traditionally been used for the treatment of malaria, and allylpyrocatechol (1), a constituent of P. betle, has been shown to exhibit anti-malarial activities. In this study, we verified that 1 showed in vivo anti-malarial activity through not only intraperitoneal (i.p.) but also peroral (p.o.) administration. Additionally, some analogs of 1 were synthesized and the structure–activity relationship was analyzed to disclose the crucial sub-structures for the potent activity.
- Horii, Toshihiro,Itagaki, Sawako,Kawano, Tomikazu,Miyoshi, Akihito,Murakami, Nobutoshi,Tamura, Satoru
-
p. 784 - 790
(2020/09/18)
-
- Chemoselective rearrangement reactions of sulfur ylide derived from diazoquinones and allyl/propargyl sulfides
-
Here, we describe three types of rearrangement reactions of sulfur ylide derived from diazoquinones and allyl/ propargyl sulfides. With Rh2(esp)2 as the catalyst, diazoquinones react with allyl/propargyl sulfides to form a sulfur ylide, which undergoes a chemoselective tautomerization/[2,3]-sigmatropic rearrangement reaction, a Doyle?Kirmse rearrangement/Cope rearrangement cascade reaction, or a Doyle?Kirmse rearrangement/elimination reaction, depending on the substituent of the sulfides. The protocol provides alkenyl and allenyl sulfides and multisubstituted phenols with moderate and high yields.
- Zhou, Cong-Ying,Yan, Sijia,Rao, Junxin
-
p. 9091 - 9096
(2020/12/02)
-
- MIDA boronate allylation-synthesis of ibuprofen
-
MIDA boronates are among the most useful reagents for the Suzuki-Miyaura reaction. This chemistry typically generates new bonds between two aromatic rings, thereby restricting access to important areas of chemical space. Here we demonstrate the coupling of MIDA boronates to allylic electrophiles, including a new synthesis of the well-known COX inhibitor ibuprofen. This journal is
- Brodie, Glen,France, David J.,Memarzadeh, Sarah,Phillips, David,Tang, Gi Lum
-
p. 30624 - 30630
(2020/09/11)
-
- Cleavage of Catechol Monoalkyl Ethers by Aluminum Triiodide-Dimethyl Sulfoxide
-
Using eugenol and vanillin as model substrates, a practical method is developed for the cleavage o -hydroxyphenyl alkyl ethers. Aluminum oxide iodide (O=AlI), generated in situ from aluminum triiodide and dimethyl sulfoxide, is the reactive ether cleaving species. The method is applicable to catechol monoalkyl ethers as well as normal phenyl alkyl ethers for the removal of methyl, ethyl, isopropyl, and benzyl groups. A variety of functional groups such as alkenyl, allyl, amide, cyano, formyl, keto, nitro, and halogen are well tolerated under the optimum conditions. Partial hydrodebromination was observed during the demethylation of 4-bromoguaiacol, and was resolved using excess DMSO as an acid scavenger. This convenient and efficient procedure would be a practical tool for the preparation of catechols.
- Sang, Dayong,Tian, Juan,Tu, Xiaodong,He, Zhoujun,Yao, Ming
-
p. 704 - 712
(2019/01/23)
-
- Carbonylative Transformation of Allylarenes with CO Surrogates: Tunable Synthesis of 4-Arylbutanoic Acids, 2-Arylbutanoic Acids, and 4-Arylbutanals
-
In this Communication, procedures for the selective synthesis of 4-arylbutanoic acids, 2-arylbutanoic acids, and 4-arylbutanals from the same allylbenzenes have been developed. With formic acid or TFBen as the CO surrogate, reactions proceed selectively and effectively under carbon monoxide gas-free conditions.
- Wu, Fu-Peng,Li, Da,Peng, Jin-Bao,Wu, Xiao-Feng
-
supporting information
p. 5699 - 5703
(2019/08/01)
-
- Hydrogenolysis of lignin model compounds into aromatics with bimetallic Ru-Ni supported onto nitrogen-doped activated carbon catalyst
-
Lignin is the most abundant and renewable resources for production of natural aromatics. In this paper, new bimetallic catalytic system of Ru and Ni supported onto nitrogen-doped activated carbon (Ru-Ni-AC/N) was developed and its performances on hydrogenolysis of lignin model compounds under mild reaction conditions (1.0 MPa, 230 °C, in aqueous) were investigated. The results indicate that Ru-Ni-AC/N was a highly active, selective and stable catalyst for the conversion of lignin model compounds into aromatics, e.g. phenol, benzene and their derivatives. As verified by BET, XRD, HRTEM, XPS, H2-TPR and ICP-MS, the strong synergistic effects between i) Ru and Ni and ii) metals and N-groups were contributed to its excellent aromatics selectivity. What's more, the introduction of electron rich N atoms on AC was beneficial to the stabilization of metal particles, which greatly enhanced the durability of the catalyst.
- Hu, Yinghui,Jiang, Guangce,Xu, Guoqiang,Mu, Xindong
-
p. 316 - 326
(2018/01/05)
-
- Quality-In(Process)Line (QuIProLi) process intensification for a micro-flow UV-photo synthesis enabled by online UHPLC analysis
-
Process intensification commonly enables reaction acceleration and therefore continuous-flow/PAT is urgently needed. The low volumes typical for micro-flow pose challenges for online sampling operations in analytics. In this paper, a very fast process is combined with a modified ultra-high-performance liquid chromatography (UHPLC) system allowing for very fast sampling and analysis. Low-volume online sampling according to the needs posed by PAT for pharma quality control, is introduced here for UHPLC analysis of the photo-Claisen rearrangement in micro-flow. Chances and challenges are critically reviewed, including the reproducibility and robustness of the sampling. Furthermore, the ability and speed of the chosen set-up in order to capture process changes and adjust the process parameters properly is investigated. With the applied online sampling system, it was possible to perform, almost unattended and spending 12 times less sampling volume, a full factorial analysis of all relevant reaction conditions (243 experiments) in three days. Such quality-in-the-process-line (QuIProLi) online sampling avoided random errors due to automation.
- Escribà-Gelonch, Marc,Shahbazali, Elnaz,Honing, Maarten,Hessel, Volker
-
p. 3143 - 3151
(2018/02/19)
-
- Ether bond cracking method of phenylalkyl ether
-
The invention discloses an ether bond cracking method of phenylalkyl ether. The method comprises the following steps: performing ether bond breaking reaction on phenylalkyl ether at -20 to reflux temperature in the presence of aluminium triiodide and dimethyl sulfoxide, thereby generating phenol and derivatives thereof. The method disclosed by the invention is mild in condition, simple and convenient for operation, high in yield, and extensive in applicable phenylalkyl ether range.
- -
-
Paragraph 0169-0171
(2018/11/26)
-
- Ether bond dissociation method of phenylalkyl ether
-
The invention discloses an ether bond dissociation method of phenylalkyl ether. The ether bond dissociation method of phenylalkyl ether includes the following steps that in organic solvent, in the presence of aluminium trihalogen, metal iodide and acid scavenging agents, phenylalkyl ether is subjected to an ether bond dissociation reaction at -20 DEG C to reflux temperature to generate phenol andderivatives thereof. The ether bond dissociation method of phenylalkyl ether is mild in condition, convenient to operate, high in yield and wide in phenylalkyl ether applicable range.
- -
-
Paragraph 0089; 0090; 0091
(2018/09/29)
-
- Structure–activity relationships and docking studies of hydroxychavicol and its analogs as xanthine oxidase inhibitors
-
Hydroxychavicol (HC), which is obtained from the leaves of Piper betle LINN. (Piperaceae), inhibits xanthine oxidase (XO) with an IC50 value of 16.7μM, making it more potent than the clinically used allopurinol (IC50=30.7μM). Herein, a structure–activity relationship analysis of the polar part analogs of HC was conducted and an inhibitor was discovered with a potency 13 times that of HC. Kinetic studies have revealed that HC and its active analog inhibit XO in an uncompetitive manner. The binding structure prediction of these inhibitor molecules to the XO complex with xanthine suggested that both compounds (HC and its analog) could simultaneously form hydrogen bonds with xanthine and XO.
- Nishiwaki, Keiji,Ohigashi, Kanae,Deguchi, Takahiro,Murata, Kazuya,Nakamura, Shinya,Matsuda, Hideaki,Nakanishi, Isao
-
p. 741 - 747
(2018/07/05)
-
- Ether bond breakage method for phenylalkyl ethers
-
The invention discloses an ether bond breakage method for phenylalkyl ethers. The method comprises the step: subjecting the phenylalkyl ethers to an ether bond breakage reaction at the temperature of -20 DEG C to reflux temperature in an organic solvent in the presence of aluminum triiodide and carbodiimide, so as to produce phenols and derivatives thereof. The method is moderate in conditions, simple and convenient in operation, high in yield and wide in applicable phenylalkyl ether range.
- -
-
Paragraph 0153-0155
(2017/07/19)
-
- Catalytic Oxidative Trifluoromethoxylation of Allylic C?H Bonds Using a Palladium Catalyst
-
A catalytic intermolecular allylic C?H trifluoromethoxylation reaction of alkenes has been developed based on the use of a palladium catalyst, CsOCF3 as the trifluoromethoxide source, and benzoquinone as the oxidant. This reaction provides an efficient route for directly accessing allylic trifluoromethoxy derivatives with excellent regioselectivities from terminal alkenes via an allylic C?H bond activation process.
- Qi, Xiaoxu,Chen, Pinhong,Liu, Guosheng
-
supporting information
p. 9517 - 9521
(2017/08/01)
-
- Carbodiimides as Acid Scavengers in Aluminum Triiodide Induced Cleavage of Alkyl Aryl Ethers
-
A practical procedure for the cleavage of alkyl aryl ethers containing labile functional groups has been developed using aluminum triiodide as the ether cleaving reagent. Carbodiimides, typically used as dehydration reagents for the coupling of amines and carboxylic acids to yield amide bonds, are found to be effective hydrogen iodide scavengers that prevent acid-labile groups from deterioration. The method is applicable to variant alkyl aryl ethers such as eugenol, vanillin, ortho -vanillin and methyl eugenol. Suitable substrates are not limited to alkyl o -hydroxyphenyl ethers.
- Sang, Dayong,Wang, Jiahui,Zheng, Yun,He, Jianyuan,Yuan, Caili,An, Qing,Tian, Juan
-
p. 2721 - 2726
(2017/06/13)
-
- A phenyl alkyl ether ether linkage breaking method (by machine translation)
-
The invention discloses a phenyl alkyl ether ether linkage breaking method, the method is: in the organic solvent, in the presence of a mineral acid and the aluminium triiodide scavenging agent under the conditions of, phenyl ether in the - 20 °C to reflux temperature lower ether linkage breaking reaction, generating phenol and its derivatives. The mild conditions, the operation is simple, and the yield is high, the applicable phenyl ether range is wide. (by machine translation)
- -
-
Paragraph 0090-0092
(2018/04/01)
-
- Flow Metal-Free Ar-C Bond Formation via Photogenerated Phenyl Cations
-
A convenient photochemical flow protocol for the formation of aryl-carbon bonds via photogenerated phenyl cations has been developed. A wide range of phenylated products, including biaryls, allylarenes, 2-arylacetals and benzyl γ-lactones, was smoothly synthesized in satisfactory yields under metal-free conditions. The adoption of a flow reactor often allowed us to adopt higher concentrations of substrates and shorter irradiation times compared to those usually employed in batch systems.
- Bergami, Matteo,Protti, Stefano,Ravelli, Davide,Fagnoni, Maurizio
-
supporting information
p. 1164 - 1172
(2016/04/19)
-
- Concise synthesis of broussonone A
-
A concise and expeditious approach to the total synthesis of broussonone A, a p-quinol natural compound, has been developed. The key features of the synthesis include the Grubbs II catalyst mediated cross metathesis of two aromatic subunits, and a chemoselective oxidative dearomatizationin the presence of two phenol moieties. Especially, optimization associated with the CM reaction of ortho-alkoxystyrenes was also studied, which are known to be ineffective for Ru-catalyzed metathesis reactions under conventional reaction conditions because ortho-alkoxy group could coordinate to the ruthenium center, resulting in the potential complication of catalyst inhibition.
- Jo, Hyeju,Choi, Minho,Viji, Mayavan,Lee, Young Hee,Kwak, Young-Shin,Lee, Kiho,Choi, Nam Song,Lee, Yeon-Ju,Lee, Heesoon,Hong, Jin Tae,Lee, Mi Kyeong,Jung, Jae-Kyung
-
p. 15966 - 15975
(2015/12/01)
-
- Phosphine-Free Suzuki Cross-Coupling Reaction Using an Efficient and Reusable Pd Catalyst in an Aqueous Medium under Microwave Irradiation
-
We report here an improved, highly efficient, and general method for the ligand-free Suzuki cross-coupling reaction to the synthesis of biaryls, bipyridyls, thienylpyridine, and allylphenols. Microwave irradiation of (het)aryl halides and (hetaryl, allyl)arylboronic acid N-methyl-iminodiacetic acid (MIDA) ester, using polyurea microencapsulated palladium catalyst (Pd EnCat 30), gave the coupling adducts 1a-x in excellent yields in just 10-18 min.
- Da Silva, Joaquim F. M.,Yepes Perez, Andres F.,De Almeida, Natália P.
-
supporting information
p. 1995 - 2004
(2015/08/18)
-
- NEW CYCLOHEXYL AND QUINUCLIDINYL CARBAMATE DERIVATIVES HAVING BETA2 ADRENERGIC AGONIST AND M3 MUSCARINIC ANTAGONIST ACTIVITY
-
The present invention relates to novel compounds having β2 adrenergic agonist and M3 muscarinic antagonist dual activity, to pharmaceutical compositions containing them, to the process for their preparation and to their use in respiratory therapies.
- -
-
Page/Page column 161
(2014/07/08)
-
- Hydrazone-palladium-catalyzed allylic arylation of cinnamyloxyphenylboronic acid pinacol esters
-
Allylic arylation of cinnamyloxyphenylboronic acid pinacol esters 3, which have arylboronic acid moiety and allylic ether moiety, using a hydrazone 1d-Pd(OAc)2 system proceeded and gave the corresponding 1,3-diarylpropene derivatives 4 with a phenolic hydroxyl group via a selective coupling reaction of the π-allyl intermediate to the boron-substituted position of the leaving group.
- Watanabe, Kohei,Mino, Takashi,Abe, Taichi,Kogure, Taketo,Sakamoto, Masami
-
p. 6695 - 6702
(2014/08/05)
-
- Allyl/propenyl phenol synthases from the creosote bush and engineering production of specialty/commodity chemicals, eugenol/isoeugenol, in Escherichia coli
-
The creosote bush (Larrea tridentata) harbors members of the monolignol acyltransferase, allylphenol synthase, and propenylphenol synthase gene families, whose products together are able to catalyze distinct regiospecific conversions of various monolignols into their corresponding allyl- and propenyl-phenols, respectively. In this study, co-expression of a monolignol acyltransferase with either substrate versatile allylphenol or propenylphenol synthases in Escherichia coli established that various monolignol substrates were efficiently converted into their corresponding allyl/propenyl phenols, as well as providing proof of concept for efficacious conversion in a bacterial platform. This capability thus potentially provides an alternate source to these important plant phytochemicals, whether for flavor/fragrance and fine chemicals, or ultimately as commodities, e.g.; for renewable energy or other intermediate chemical purposes. Previous reports had indicated that specific and highly conserved amino acid residues 84 (Phe or Val) and 87 (Ile or Tyr) of two highly homologous allyl/propenyl phenol synthases (circa 96% identity) from a Clarkia species mainly dictate their distinct regiospecific catalyzed conversions to afford either allyl- or propenyl-phenols, respectively. However, several other allyl/propenyl phenol synthase homologs isolated by us have established that the two corresponding amino acid 84 and 87 residues are not, in fact, conserved.
- Kim, Sung-Jin,Vassao, Daniel G.,Moinuddin, Syed G.A.,Bedgar, Diana L.,Davin, Laurence B.,Lewis, Norman G.
-
-
- In vitro growth inhibition of human cancer cells by novel honokiol analogs
-
Honokiol possesses many pharmacological activities including anti-cancer properties. Here in, we designed and synthesized honokiol analogs that block major honokiol metabolic pathway which may enhance their effectiveness. We studied their cytotoxicity in human cancer cells and evaluated possible mechanism of cell cycle arrest. Two analogs, namely 2 and 4, showed much higher growth inhibitory activity in A549 human lung cancer cells and significant increase of cell population in the G0-G1 phase. Further elucidation of the inhibition mechanism on cell cycle showed that analogs 2 and 4 inhibit both CDK1 and cyclin B1 protien levels in A549 cells.
- Lin, Jyh Ming,Prakasha Gowda,Sharma, Arun K.,Amin, Shantu
-
experimental part
p. 3202 - 3211
(2012/07/28)
-
- A concise synthesis of 4′-O-methyl honokiol
-
A concise and protecting group free synthesis of the naturally occurring neolignan 4′-O-methyl honokiol is developed. The key biaryl bond is constructed by 1,2-addition of an aryl Grignard reagent to a dienone followed by rearrangement.
- Denton, Ross M.,Scragg, James T.,Saska, Jan
-
supporting information; experimental part
p. 2554 - 2556
(2011/06/21)
-
- Expedient synthesis of 4-O-methylhonokiol via Suzuki-Miyaura cross-coupling
-
Concise and practical synthesis of 4-O-methylhonokiol was achieved in 34% overall yield. The key features of our synthesis include chemoselective ortho-mono bromination of phenol as well as biaryl formation via Suzuki-Miyaura cross-coupling, in which bromophenol was reacted with potassium aryltrifluoroborate using Pd(OAc)2 and RuPhos under microwave conditions.
- Kwak, Jae-Hwan,Cho, Young Ae,Jang, Jae-Yong,Seo, Seung-Yong,Lee, Heesoon,Hong, Jin Tae,Han, Sang-Bae,Lee, Kiho,Kwak, Young-Shin,Jung, Jae-Kyung
-
scheme or table
p. 9401 - 9404
(2011/12/14)
-
- Total synthesis of rhoiptelol B
-
A simple and efficient total synthesis of rhoiptelol B, isolated from the the leaves and fruits of Rhoiptelea chiliantha, is achieved using Sharpless asymmetric epoxidation, 1,3-anti-chiral allylation, olefin cross-metathesis, Sharpless asymmetric dihydroxylation, and ferric chloride catalyzed intramolecular SN2 cyclization as the key steps
- Yadav,Pandurangam,Reddy, V. V. Bhadra,Reddy, B. V. Subba
-
scheme or table
p. 4300 - 4306
(2011/02/25)
-
- A concise synthesis of dunnianol
-
A short total synthesis of the neosesquilignan dunnianol which features a double Suzuki cross-coupling as a key step is described. Georg Thieme Verlag Stuttgart.
- Denton, Ross M.,Scragg, James T.
-
scheme or table
p. 633 - 635
(2010/10/01)
-
- Design, synthesis and SAR studies of 4-allyoxyaniline amides as potent 15-lipoxygensae inhibitors
-
A group of 4-allyloxyaniline amides 5a-o were designed, synthesized and evaluated as potential inhibitors of soybean 15-lipoxygenase (SLO) on the basis of eugenol and esteragol structures. Compound 5e showed the best IC50 in SLO inhibition (IC50 = 0.67 ± 0.06 μM). All compounds were docked in SLO active site retrieved from RCSB Protein Data Bank (PDB entry: 1IK3) and showed that allyloxy group of compounds is oriented towards the Fe3+-OH moiety in the active site of enzyme and fixed by hydrogen bonding with two conserved His513 and Gln716. It is resulted that molecular volume of the amide moiety would be a major factor in inhibitory potency variation of the synthetic amides, where the hydrogen bonding of the amide group could also involve in the activity of the inhibitors.
- Seyedi, Seyed Mohammad,Jafari, Zeinab,Attaran, Neda,Sadeghian, Hamid,Saberi, Mohammad Reza,Riazi, Mohammad Mahdi
-
experimental part
p. 1614 - 1622
(2009/08/15)
-
- Development of highly chemoselective bulky zincate complex, tBu 4ZnLi2: Design, structure, and practical applications in small-/macromolecular synthesis
-
We present full details of the unique reactivities of the newly developed dianion-type bulky zincate, dilithium tetra-ferf-butylzincate (tBu 4ZnLi2). With this reagent, halogen-zinc exchange reaction of variously functionalized haloaromatics and anionic polymerization of N-isopropylacrylamide (NIPAm)/styrene with excellent chemoselectivity were realized. Halogen-zinc exchange reaction followed by electrophilic trapping with propargyl bromide provided a convenient route to functionalized phenylallenes, particularly those with electrophilic functional groups (such as cyano, amide and halogens). Spectral and computational studies of the structure in the gas and liquid phases indicated extraordinary stabilization of this dianion-type zincate by its bulky ligands.
- Furayama, Taniyuki,Yonehara, Mitsuhiro,Arimoto, Sho,Kobayashi, Minoru,Matsumoto, Yotaro,Uchiyama, Masanobu
-
supporting information; experimental part
p. 10348 - 10356
(2009/10/10)
-
- Sulfoxide-directed desymmetrisation of cyclohexa-1,4-dienes
-
Cyclohexa-2,5-dien-1-ylmethanol derivatives have been subjected to a short sequence featuring esterification to introduce a malonate side-chain, oxidation of the doubly allylic position and stereoselective cyclisation. When used in conjunction with a chiral sulfoxide, the cyclisation is diastereoselective (2:1) favouring one of the diastereotopic double-bonds.
- Elliott, Mark C.,El Sayed, Nahed Nasser Eid,Ooi, Li-ling
-
p. 4561 - 4564
(2008/02/04)
-
- Process for the synthesis of biologically active oxygenated compounds by dealkylation of the corresponding alkylethers
-
Alkoxy aromatic compounds are conveniently dealkylated to the corresponding phenolic compounds by treatment with aluminum chloride/N,N-dimethyl aniline complex. Aromatic poly O-demethylation is a unique feature of this invention. This process is applicable to the manufacture of polyphenols such as Resveratrol, Oxyresveratrol, Gnetol.
- -
-
Page/Page column 6-7
(2008/06/13)
-
- USE OF CHAVICOL FOR THE TREATMENT OF SUPERFINFECTED OILY SKIN AND SCALP
-
Chavicol has been found to possess a dual-action in the treatment of superinfected oily skin and scalp by sebum reduction coupled with biocidal activity on lipophilic anaerobic micro-organisms, whilst possessing no significant estrogenic nor sensitizing potentials. It is thus indicated for the manufacture of orally or topically administrable compositions for the treatment of superinfected oily skin and/or scalp and, in particular, for the treatment of androgenic disorders of skin and/or scalp such androgenic disorders incude alopecia, acne, seborrhea and/or dandruff.
- -
-
Page/Page column 11
(2008/06/13)
-
- Toward a protecting-group-free halogen-metal exchange reaction: Practical, chemoselective metalation of functionalized aromatic halides using dianion-type zincate,tBu4ZnLi2
-
A versatile preparation method for aromatic zincate compounds through a halogen-zinc exchange reaction using dilithium tetra-tert-butylzincate (tBu4ZnLi2) has been developed. This reagent permits efficient preparation of highly functionalized aromatic zincates, particularly, those with electrophilic functional groups, such as ester, amide, alcohol, and phenol. Halogen-zinc exchange reactions followed by electrophilic trapping (with allyl bromide or benzaldehyde) proved to be a powerful tool for C-C bond formation on functionalized aromatic rings. The functionalized aromatic zincate intermediate was also found to undergo copper- and palladium-catalyzed C-C bond-forming reactions with good yields and high chemoselectivity. Copyright
- Uchiyama, Masanobu,Furuyama, Taniyuki,Kobayashi, Minoru,Matsumoto, Yotaro,Tanaka, Kentaro
-
p. 8404 - 8405
(2007/10/03)
-
- Chavicol formation in sweet basil (Ocimum basilicum): Cleavage of an esterified C9 hydroxyl group with NAD(P)H-dependent reduction
-
Propenyl- and allyl-phenols, such as methylchavicol, p-anol and eugenol, have gained importance as flavoring agents and also as putative precursors in the biosynthesis of 9,9′-deoxygenated lignans, many of which have potential medicinal applications. In spite of several decades of investigation, however, the complete biosynthetic pathway to a propenyl/allylphenol had not yet been reported. We have subjected a Thai basil variety accumulating relatively large amounts of the simplest volatile allylphenol, methylchavicol, to in vivo administration of radiolabeled precursors and assays of protein preparations in vitro. Through these experiments, the biosynthesis of chavicol was shown to occur via the phenylpropanoid pathway to p-coumaryl alcohol. Various possibilities leading to deoxygenation of the latter were examined, including reduction of the side-chain double bond to form p-dihydrocoumaryl alcohol, followed by dehydration to afford chavicol, as well as formation of p-methoxycinnamyl alcohol, with further side-chain modification to afford methylchavicol. A third possibility studied was activation of the side-chain alcohol of p-coumaryl alcohol, e.g. via esterification, to form a more facile leaving group via reductive elimination. The latter was shown to be the case using p-coumaryl esters as potential substrates for a NAD(P)H-dependent reductase to afford chavicol, which is then O-methylated to afford methylchavicol. The Royal Society of Chemistry 2006.
- Vassao, Daniel G.,Gang, David R.,Koeduka, Takao,Jackson, Brenda,Pichersky, Eran,Davin, Laurence B.,Lewis, Norman G.
-
p. 2733 - 2744
(2008/10/09)
-
- The synthesis of phenolic propane-1, 2- and 1,3-diols as intermediates in immobilised chelatants for the borate anion
-
The isomeric 3-(hydroxyphenyl)propane-1, 2-diols have been synthesised from allylic precursors by epoxidation and cleavage. Several different methods have been examined for obtaining 1-(methoxyphenyl)propane-1, 3-diols. 2-(methoxyphenyl)propane-1, 3-diols and certain hydroxy analogues have been obtained from benzaldoximes converted by oxidation to methoxy- and benzyloxynitromethylbenzenes followed by hydroxymethylation with formaldehyde and catalytic hydrogenation.
- Tyman, John H. P.,Payne
-
p. 691 - 695
(2007/10/03)
-
- Cytotoxic neolignans: An SAR study
-
The cytotoxic effects of different neolignans with the structure 1 were studied. The neolignans, magnolol 1 and honokiol 2 have been reported to inhibit the growth of several tumor cell lines in vitro and in vivo. The chemical structure of magnolol and honokiol consists of biphenyl skeleton with phenolic and allylic functionalities. Analogs of 1 and 2 containing different substitution have been studies for their effect on the growth of Hep-G2 and their structure-activity relationships were reported in this work.
- Kong, Zwe-Ling,Tzeng, Shin-Cheng,Liu, Yeuk-Chuen
-
p. 163 - 166
(2007/10/03)
-
- Expeditious synthesis of bioactive allylphenol constituents of the genus Piper through a metal-free photoallylation procedure
-
Nine bioactive allylphenol (anisole) derivatives (e.g. eugenol, safrole and asaricin) present in several plants of the genus Piper have been synthesized in medium to high yield via aryl cation intermediates. This expeditious metal-free procedure involves the irradiation of the corresponding chlorophenols or chloroanisoles in a polar solvent (MeCN or, better, TFE or aqueous acetonitrile) in the presence of allyltrimethylsilane. Estragole has also been synthesized starting from the corresponding fluoroderivative and diazonium salt, though in a lower yield. The Royal Society of Chemistry 2005.
- Protti, Stefano,Fagnoni, Maurizio,Albini, Angelo
-
p. 2868 - 2871
(2007/10/03)
-
- One step hair coloring compositions using salts
-
A hair coloring composition comprising the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an amino phenol, a naphthol, a polyhydric phenol, a catechol and mixtures thereof; wherein the composition comprising one or more oxidative hair coloring agents further comprises al least one water soluble carbonate releasing salts; and optionally a water soluble ammonium salt, is described.
- -
-
-
- Transition metal complexes as dye forming catalysts in hair coloring compositions
-
A hair coloring composition comprising a first composition which comprises: (a) a dye forming transition metal salt or complex; which is first applied to the hair; and a second composition which comprises the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an aminophenol, a polyhydric phenol a catechol and mixtures thereof.
- -
-
-
- Rhodium- and iridium-catalyzed allylation of electron-rich arenes with allyl tosylate
-
The allylation of electron-rich arenes with allyl tosylate proceeded at 0°C in the presence of [Rh(nbd)(CH3CN)2]PF 6. Various oxygenated arenes were allylated with high para-selectivity in almost all cases. Especially in t
- Tsukada, Naofumi,Yagura, Yasushige,Sato, Tetsuo,Inoue, Yoshio
-
p. 1431 - 1434
(2007/10/03)
-
- Substituent effects on the rate constants for the photo-claisen rearrangement of allyl aryl ethers
-
The photochemistry of 11 substituted allyl 4-X- and 3-X-aryl ethers 3 (ArOCH2-CH=CH2) has been examined in both methanol and cyclohexane as solvents. The ethers react by the photo-Claisen rearrangement to give allyl substituted phenols as the major primary photoproducts, as expected from the well-established radical pair mechanism. The excited singlet state properties (absorption spectra, fluorescence spectra, fluorescence quantum yields, and singlet lifetimes) were compared with a parallel set of unreactive 4-X- and 3-X-anisoles 4. The excited-state properties of three substituted 4-X-aryl 4-(1-butenyl) ethers 14 (ArOCH2CH2-CH=CH2) were also examined. The model compounds 4 and the reactive allyl ethers 3 have essentially identical rate constants for the excited-state processes with the exception of khoms, the rate constant for homolytic cleavage from S1 of the allyl ethers to give the radical pair. The difference between the fluorescence quantum yields and/or singlet lifetimes for 3 and 4 were used to obtain values of khoms for all of the allyl ethers. These values exhibit a large substituent effect, spanning almost 2 orders of magnitude with electron-donating groups (CH3O, CH3) accelerating the reaction and electron-withdrawing ones (CN, CF3) slowing it down. The parallel range of rate constants observed in both methanol and cyclohexane indicates that ion pairs are not important intermediates in these rearrangements. Quantum yields of reaction (Φr) for several of the more reactive ethers demonstrate that neither these values nor rate constants of reaction (khomr) derived from them are reliable measures of the actual excited-state process. In fact, the khomr values are significantly lower than the khoms ones, indicating that the radical pairs undergo recombination to generate starting material. Finally, the khoms rate constants were found to parallel a trend for the change in bond dissociation energy (ΔBDE) for the O-C (allyl) bond of the allyl ethers, indicating that other possible substituent effects are of minor importance.
- Pincock, Alexandra L.,Pincock, James A.,Stefanova, Roumiana
-
p. 9768 - 9778
(2007/10/03)
-
- Discovery of (R)-1-[2-hydroxy-3-(4-hydroxy-phenyl)-propyl]-4-(4-methyl-benzyl)-piperidin- 4-ol: A novel NR1/2B subtype selective NMDA receptor antagonist
-
Starting from Ro-25-6981 as a lead compound, highly potent and selective NR1/2B subtype selective NMDA receptor antagonists, with low activity at α1 adrenergic receptors were developed.
- Pinard, Emmanuel,Alanine, Alexander,Bourson, Anne,Buettelmann, Bernd,Gill, Ramanjit,Heitz, Marie-Paule,Jaeschke, Georg,Mutel, Vincent,Trube, Gerhard,Wyler, Rene
-
p. 2173 - 2176
(2007/10/03)
-
- Insulated molecular wires: Dendritic encapsulation of poly(triacetylene) oligomers, attempted dendritic stabilization of novel poly(pentaacetylene) oligomers, and an organometallic approach to dendritic rods
-
Multinanometer-long end-capped poly(triacetylene) (PTA) and poly(pentaacetylene) (PPA) oligomers with dendritic side chains were synthesized as insulated molecular wires. PTA Oligomers with laterally appended Frechet-type dendrons of first to third generation were prepared by attaching the dendrons (8, 13, and 17, respectively. Scheme 1) to (E)-enediyne 18 by a Mitsunobu reaction and subsequent Glaser-Hay oligomerization under end-capping conditions (Scheme 2). Whereas first-generation oligomers up to the pentamer were isolated (1a-e), for reasons of steric overcrowding, only oligomers up to the trimer (2a-c) were formed at the second-generation level, and only the end-capped monomer and dimer (3a.b) were isolated at the third-generation level. By repetitive sequences of hydrosilylation (with the Karstedt catalyst), followed by allylation or vinylation, a series of carbosilane dendrons were also prepared (Schemes 3 and 4). Attachment of the second-generation wedge 40 to (E)-enediyne 18, followed by deprotection and subsequent end-capping Hay oligomerization, provided PTA oligomers 4a-d with lateral carbosilane dendrons (Scheme 5). UV/VIS Studies (Figs. 5-10) demonstrated that the insulating dendritic layers did not alter the electronic characteristics of the PTA backbone, even at the higher-generation levels. Despite distortion from planarity due to the bulky dendritic wedges, no loss of π-electron conjugation along the PTA backbone was detected. A surprising (E)-(Z) isomerization of the diethynylethene (DEE) core in the third generation derivative 3a was observed, possibly photosensitized by the bulky Frechet-type dendritic wedge. Electrochemical investigations by steady-state voltammetry and cyclic voltammetry showed that the first reduction potential of the PTA oligomer with Frechet-type dendrons is shifted to more negative values as the dendritic coverage increases. With compounds 5a-c, the first oligomers with a poly(pentaacetylene) backbone were obtained by oxidative Hay oligomerization under end-capping conditions (Scheme 6). The synthesis of dendritic PPA oligomers by oxidative coupling of (E)-enetetrayne 60 under end-capping conditions provided oligomers 61a-d, which were formed as mixtures of stereoisomers due to unexpected thermal (E)-(Z) isomerization (Scheme 8). In another novel approach towards dendritic encapsulation of molecular wires with a Pt-bridged tetraethynylethene (TEE) oligomeric backbone, the trans-dichloroplatinum(II) complex trans-67 with dendritic phosphane ligands (Fig. 14) was coupled under Hagihara conditions to mono-deprotected 69 under formation of the extended monomer 65 (Scheme 12). Again, an unexpected thermal (E)-(Z) isomerization, possibly induced by steric strain between TEE moieties and dendritic phosphane ligands in the unstable complex, led to the isolation of 65 as an isomeric mixture only.
- Schenning, Albertus P. H. J.,Arndt, Jan-Dirk,Ito, Masato,Stoddart, Alison,Schreiber, Martin,Siemsen, Peter,Martin, Rainer E.,Boudon, Corinne,Gisselbrecht, Jean-Paul,Gross, Maurice,Gramlich, Volker,Diederich, Francois
-
p. 296 - 334
(2007/10/03)
-
- 4-HYDROXY-PIPERODINE DERIVATIVES
-
The present invention relates to compounds of the formula STR1 wherein x is--O--,--NH--,--CH 2--,--CH=,--CO 2--,--CONH--,--CON(lower alkyl)--,--S--and--SO 2--; R. sup.1-R. sup.4 are, independently from each other hydrogen, halogen, hydroxy, amino, nitro, lower-alkyl-sulfonylamido, 1-or 2-imidazolyl, 1-(1,2,4-triazolyl) or acetamido;R 5, R 6 are, independently from each other hydrogen, lower-alkyl, hydroxy, lower alkoxy or oxo;R. sup.7-R 10 are, independently from each other hydrogen, lower-alkyl, halogen, trifluoromethyl or lower-alkoxy;n is 0 or 1; and to pharmaceutically acceptable acid addition salts thereof. Compounds of the present invention are NMDA(N-methyl-D-aspartate)-receptor subtype selective blockers.
- -
-
-
- Aromatic cyanate ester silane coupling agents
-
A composition of matter comprises an aromatic cyanate ester silane comprising at least one cyanate ester group and at least one hydrolyzable silyl group. In the presence of a cyanate ester resin the aromatic cyanate ester silane acts as a coupling agent to improve the adhesion of the cyanate ester to a substrate. The curable compositions are useful as reinforced composites, and as adhesive and coating compositions.
- -
-
-
- Enantioselective syntheses of (S)- and (R)-8,9 dihydroxydihydromagnolol
-
8,9-Dihydroxydihydromagnolol 5 was synthesized in four steps in which the synthesis of magnolol 4 was improved and the absolute configuration of 5 was confirmed as (R).
- Gu, Wenxin,She, Xuegong,Pan, Xinfu,Yang, Teng-Kuei
-
p. 1377 - 1380
(2007/10/03)
-
- β-cyclodextrin effects on photo-claisen rearrangement of allyl phenyl ether
-
The photo rearrangement of allyl phenyl ether (1) in water and in solutions containing β-cyclodextrin (β-CD) leads to the para (2) and ortho (3) allyl phenols and phenol (4) as principal products. The substrate associates with β-CD forming a 1:CD complex with a K(1-CD) = (4.6 ± 0.6) x 102 M-1. When the photolysis is carded out in presence of oxygen there is a decrease in the total yields of products, but the inhibition is less marked in the presence of β-CD. The product quantum yields (Φ) for the complexed substrate are different for the free substrate, being higher for the ortho product, almost the same for the para product, and lower for phenol. The ortho selectivity was confirmed in the photolysis of the solid complex; these results are in agreement with those reported by this laboratory for the photo-Fries rearrangement of acetanilide and phenyl acetate. The photo rearrangement of allyl phenyl ether (1) in water and in solutions containing β-cyclodextrin (β-CD) leads to the para (2) and ortho (3) allyl phenols and phenol (4) as principal products. The substrate associates with β-CD forming a 1:CD complex with a K1-CD = (4.6±0.6)×102 M-1. When the photolysis is carried out in presence of oxygen there is a decrease in the total yields of products, but the inhibition is less marked in the presence of β-CD. The product quantum yields (Φ) for the complexed substrate are different for the free substrate, being higher for the ortho product, almost the same for the para product, and lower for phenol. The ortho selectivity was confirmed in the photolysis of the solid complex; these results are in agreement with those reported by this laboratory for the photo-Fries rearrangement of acetanilide and phenyl acetate.
- Sanchez, Ana M.,Veglia, Alicia V.,De Rossi, Rita H.
-
p. 1151 - 1155
(2007/10/03)
-
- Synthesis of (-)-Monoterpenylmagnolol and Magnolol
-
(-)-Monoterpenylmagnolol (3) was synthesized in eight steps from (+)-3,9-dibromocamphor (4) and the bis(methoxymethyl) ether (22) of 3-(4-hydroxyphenyl)-1-propanol.Fragmentation of an endo-3-aryl-9-bromocamphor (27) provided the correct absolute stereochemistry.In this total synthesis, dissolving metal conditions were developed to reduce enol phosphate and isopropenyl functions without concomitant reduction of an attached phenol.Palladium(0)-catalyzed cross-coupling of an arylzinc chloride with 4-allyl-2-iodophenyl methoxymethyl ether (34) provided the desired tricyclic 1,2,3,5-tetrasubstituted biaryl 41 in fair yield without optimization and with little isomerization of the allyl group.Magnolol (1) was also synthesized by aryl coupling of 34 and the methoxymethyl ether of 4-allyl-2-lithiophenol via the zinc chloride method as above, as well as from 5,5'-dibromo-2,2'-dimethoxybiphenyl (37) by allylation with allyltributylstannane followed by ether cleavage.
- Agharahimi, Mohamad R.,LeBel, Norman A.
-
p. 1856 - 1863
(2007/10/02)
-