- Ester-directed orthogonal dual C-H activation and: Ortho aryl C-H alkenylation via distal weak coordination
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An unprecedented orthogonal cross-coupling between aromatic C(sp2) and aliphatic olefinic C(sp2) carbons of two same molecules via dual C-H bond activation in an intermolecular fashion has been developed using a distal ester-directing group. This new coupling reaction led to the synthesis of the highly functionalized 1,3-diaryl molecular architecture in very good yields and with high chemo- and regioselectivities. In addition, using ester as the distal directing group, ortho C-H olefination of α-methyl aryl acrylates and cinnamic esters with various alkenes has been achieved in very good yields and with a wide range of substrate scope. This journal is
- Agarwal, Vishal,Bakthadoss, Manickam,Reddy, Tadiparthi Thirupathi,Sharada, Duddu S.
-
supporting information
p. 1406 - 1409
(2022/02/09)
-
- N-Heterocyclic Carbene/Carboxylic Acid Co-Catalysis Enables Oxidative Esterification of Demanding Aldehydes/Enals, at Low Catalyst Loading
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We report the discovery that simple carboxylic acids, such as benzoic acid, boost the activity of N-heterocyclic carbene (NHC) catalysts in the oxidative esterification of aldehydes. A simple and efficient protocol for the transformation of a wide range of sterically hindered α- and β-substituted aliphatic aldehydes/enals, catalyzed by a novel and readily accessible N-Mes-/N-2,4,6-trichlorophenyl 1,2,4-triazolium salt, and benzoic acid as co-catalyst, was developed. A whole series of α/β-substituted aliphatic aldehydes/enals hitherto not amenable to NHC-catalyzed esterification could be reacted at typical catalyst loadings of 0.02–1.0 mol %. For benzaldehyde, even 0.005 mol % of NHC catalyst proved sufficient: the lowest value ever achieved in NHC catalysis. Preliminary studies point to carboxylic acid-induced acceleration of acyl transfer from azolium enolate intermediates as the mechanistic basis of the observed effect.
- Berkessel, Albrecht,Biswas, Animesh,Harnying, Wacharee,Sudkaow, Panyapon
-
supporting information
p. 19631 - 19636
(2021/08/09)
-
- Pentamethylphenyl (Ph*) and Related Derivatives as Useful Acyl Protecting Groups for Organic Synthesis: A Preliminary Study
-
A study of acyl protecting groups derived from the Ph? motif is reported. While initial studies indicated that a variety of functional groups were not compatible with the Br 2-mediated cleavage conditions required to release the Ph? group, strategies involving the use of different reagents or a modification of Ph? itself (Ph*OH) were investigated to solve this problem.
- Cheong, Choon Boon,Frost, James R.,Donohoe, Timothy J.
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p. 1828 - 1832
(2020/10/06)
-
- Novel multi-dentate phosphines for Pd-catalyzed alkoxycarbonylation of alkynes promoted by H2O additive
-
A series of novel multi (bi-/tri-/tetra-)-dentate phosphines with good robustness against water and oxygen were synthesized and fully characterized. It was found that the developed ionic tri-dentate phosphine (L2′) enabled Pd-catalyzed alkoxycarbonylation of alkynes most efficiently while H2O was used as an additive instead of acid. As for L2′, its unique steric configuration with two types of potential P-P chelation modes (P?P distance of 4.31 ? and 4.36 ? respectively) to Pd-centre rendered the corresponding Pd-catalyst high activity and good stability for alkoxycarbonylation of alkynes. The in situ FT-IR analysis also verified that the formation and stability of Pd–H active species were greatly facilitated with the presence of L2′ as well as H2O additive. In addition, as an ionic phosphine, L2′ based PdCl2(MeCN)2 system immobilized in RTIL of [Bmim]NTf2 could be recycled for 7 runs without obvious activity loss or metal leaching.
- Yang, Da,Liu, Lei,Wang, Dong-Liang,Lu, Yong,Zhao, Xiao-Li,Liu, Ye
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p. 236 - 244
(2019/02/19)
-
- Selective Palladium-Catalyzed Carbonylation of Alkynes: An Atom-Economic Synthesis of 1,4-Dicarboxylic Acid Diesters
-
A class of novel diphosphine ligands bearing pyridine substituents was designed and synthesized for the first time. The resulting palladium complexes of L1 allow for chemo- and regioselective dialkoxycarbonylation of various aromatic and aliphatic alkynes affording a wide range of 1,4-dicarboxylic acid diesters in high yields and selectivities. Kinetic studies suggest the generation of 1,4-dicarboxylic acid diesters via cascade hydroesterification of the corresponding alkynes. Based on these investigations, the chemo- and regioselectivities of alkyne carbonylations can be controlled as shown by switching the ligand from L1 to L3 or L9 to give α,β-unsaturated esters.
- Liu, Jiawang,Dong, Kaiwu,Franke, Robert,Neumann, Helfried,Jackstell, Ralf,Beller, Matthias
-
supporting information
p. 10282 - 10288
(2018/08/03)
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- Bifunctional ligands for Pd-catalyzed selective alkoxycarbonylation of alkynes
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Catalytic carbonylations of alkynes represent straightforward and atom-economic synthesis of α,β-unsaturated carbonyl compounds. One of the issues associated with the currently known catalytic systems is insufficient efficiency. In this context, Pd/ligand-catalyzed regioselective and efficient alkoxycarbonylation of terminal alkynes is desirable for the synthesis of α,β-unsaturated esters. Herein, we present the use of a newly designed bifunctional ligand for efficient Pd-catalyzed alkoxycarbonylation of alkynes. Both aliphatic and aromatic alkynes were smoothly transformed to the branched desired products with high selectivity (28 examples, 45–96% yields, 95.0–99.9% selectivity).
- Qi, Huimin,Huang, Zijun,Wang, Menglan,Yang, Peiju,Du, Chen-Xia,Chen, Shu-Wei,Li, Yuehui
-
-
- Cobalt-Catalyzed Cross-Coupling of Grignards with Allylic and Vinylic Bromides: Use of Sarcosine as a Natural Ligand
-
Sarcosine was discovered to be an excellent ligand for cobalt-catalyzed carbon-carbon cross-coupling of Grignard reagents with allylic and vinylic bromides. The Co(II)/sarcosine catalytic system is shown to perform efficiently when phenyl and benzyl Grignards are coupled with alkenyl bromides. Notably, previously unachievable Co-catalyzed coupling of allylic bromides with Grignards to linearly coupled α-products was also realized with Co(II)/sarcosine catalyst. This method was used for efficient preparation of the key intermediate in an alternative synthesis of the antihyperglycemic drug sitagliptin.
- Frlan, Rok,Sova, Matej,Gobec, Stanislav,Stavber, Gaj,?asar, Zdenko
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p. 7803 - 7809
(2015/08/18)
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- D-Glucosamine in iron-catalysed cross-coupling reactions of Grignards with allylic and vinylic bromides: Application to the synthesis of a key sitagliptin precursor
-
A sustainable D-glucosamine ligand is successfully introduced into iron-catalysed C-C cross-coupling reactions for the first time. The Fe(acac)2/D-glucosamine·HCl/Et3N catalytic system was effective at 5 mol% loading in coupling reactions of Grignard reagents with organic bromides. Moderate to high efficiency was achieved with preserved stereochemistry when allyl (Csp3) or alkenyl (Csp2) bromides were coupled with phenylmagnesium (Csp2) or benzylmagnesium (Csp3) bromides. The catalytic system developed was also successfully applied for the novel and economic preparation of a Michael-acceptor-like starting material used in an alternative synthesis of the drug sitagliptin, a known blockbuster for the treatment of type II diabetes mellitus.
- Sova, Matej,Frlan, Rok,Gobec, Stanislav,Stavber, Gaj,asar, Zdenko
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p. 528 - 535
(2015/08/04)
-
- A versatile approach to noncoded β-hydroxy-α-amino esters and α-amino acids/esters from morita-baylis-hillman adducts
-
A simple and straightforward approach to the diastereoselective synthesis of noncoded β-hydroxy-α-amino esters from Morita-Baylis-Hillman (MBH) adducts is described. The strategy is based on a one-pot sequence involving an oxidative cleavage of the double bond of silylated Morita-Baylis-Hillman adducts, followed by the reaction with hydroxylamine hydrochloride/pyridine to form oximes. The stereoselective reduction of the oximes with the mixture MoCl5·nH2O/NaBH3CN led to the corresponding anti-β-hydroxy-α-amino esters in four steps in good overall yield and with diastereoselectivity higher than 95%. A slight modification of the synthetic approach has allowed for the racemic synthesis of a set of noncoded α-amino esters/acids and DOPA
- Ullah, Hamid,Ferreira, Andr V.,Bendassolli, Jos A.,Rodrigues, Manoel T.,Formiga, Andr Luiz B.,Coelho, Fernando
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p. 113 - 123
(2015/02/02)
-
- High-yielding sequential one-pot synthesis of chiral and achiral α-substituted acrylates via a metal-free reductive coupling reaction
-
A general process for the high-yielding synthesis of substituted chiral and achiral α-substituted acrylates was achieved through the sequential one-pot combination of a metal-free reductive coupling reaction followed by an Eschenmoser methylenation. The proline catalyzed reaction of Meldrum's acid, aldehydes and Hantzsch ester followed by methylenation was successful with Eschenmoser's salt in the presence of an alcohol solvent. Herein, we have shown the high-yielding synthesis of privileged building blocks from chiral/achiral α-substituted acrylates and shown them to be very good intermediates in the pharmaceuticals and natural products synthesis. This journal is the Partner Organisations 2014.
- Ramachary, Dhevalapally B.,Venkaiah, Chintalapudi,Reddy, Y. Vijayendar
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supporting information
p. 5400 - 5406
(2014/07/21)
-
- Pd-catalyzed ligand-free Suzuki reaction of β-substituted allylic halides with arylboronic acids in water
-
The catalyst system consisting of Pd(TFA)2 and KOH allows for a wide range of β-substituted allylic halides to react efficiently with various arylboronic acids in neat water under ligand-free conditions, affording the allylated arenes in high yields with broad functional group tolerance and up to 7.4 × 105 TON and 15416 h-1 TOF.
- Dong, Chaonan,Zhang, Lingjuan,Xue, Xiao,Li, Huanrong,Yu, Zhiyong,Tang, Weijun,Xu, Lijin
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p. 11152 - 11158
(2014/03/21)
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- An efficient palladium(II) catalyst for oxidative Heck-type reaction under base-free conditions
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An efficient catalytic system for the palladium-catalyzed oxidative Heck reaction between arylboronic acids and various alkenes has been developed. Using the bis(aminoalkoxy)palladium complex of N,N-dimethylethanolamine as a catalyst, a series of substituted alkenes were obtained in moderate to excellent yields under mild reaction conditions. This protocol could be tolerated to arylboronic acids containing electron-donating or withdrawing groups and a wide range of olefins, such as acrylate, allyl esters, allyl ethers and alkenylphosphonate. A plausible reaction mechanism of the oxidative Heck reaction was proposed.
- Mi, Xia,Huang, Mengmeng,Guo, Hai,Wu, Yangjie
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p. 5123 - 5128
(2013/06/27)
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- Pd-catalyzed threefold arylation of Baylis-Hillman bromides and acetates with triarylbismuth reagents
-
Functionalized alkyl 2-benzylacrylates and 2-benzylacrylonitriles were synthesized by means of atom-economic cross-couplings of Baylis-Hillman bromides or acetates with BiAr3 under palladium-catalyzed conditions. These reactions, involving thre
- Rao, Maddali L. N.,Giri, Somnath
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p. 4580 - 4589
(2012/11/07)
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- The ligand and base-free Pd-catalyzed oxidative Heck reaction of arylboronic acids and olefins
-
Highly effective Pd-catalyzed Heck-type oxidative couplings between arylboronic acids and terminal olefins were reported. It is noteworthy that such reactions could be carried out in the absence of the base and the ligand.
- Sun, Peng,Zhu, Yan,Yang, Hailong,Yan, Hong,Lu, Linhua,Zhang, Xiang,Mao, Jincheng
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scheme or table
p. 4512 - 4515
(2012/07/14)
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- Microwave-assisted synthesis of the (E)-α-methylalkenoate framework from multifunctionalized allylic phosphonium salts
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A convenient and general microwave-assisted method for the synthesis of stereochemically defined α-methylalkenoic acids and esters from allylic phosphonium salts in a basic aqueous medium is described. A selective preparation of acids or esters was dependent on the base (NaOH or NaHCO 3) employed in the reaction and could be achieved with good to excellent yields under mild conditions in the absence of hydrides and reducing agents.
- Meier, Lidiane,Ferreira, Misael,Sa, Marcus M.
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experimental part
p. 179 - 186
(2012/07/14)
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- Pyridine ligands as promoters in PdII/0-catalyzed C-H olefination reactions
-
Commercially available pyridine ligands can significantly enhance the rate, yield, substrate scope, and site selectivity of arene C-H olefination (Fujiwara-Moritani) reactions. The use of a 1:1 ratio of Pd/pyridine proved critical to maximize reaction rates and yields.
- Kubota, Asako,Emmert, Marion H.,Sanford, Melanie S.
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supporting information; experimental part
p. 1760 - 1763
(2012/05/20)
-
- Stereoselective homogeneous catalytic arylation of methyl methacrylate: Experimental and computational study
-
Catalytic systems trans-[PdCl2(DEA)2]/DEA and trans-[PdCl2(DEA)2]/[DEA][HAc], used in the model reaction of methyl methacrylate with iodobenzene, 4-iodoanisole, and bromobenzene, provide homogeneous catalysis, good regioselectivity and excellent stereoselectivity. The major product of the regioselective reaction is internal olefin. In all examined cases the only stereoisomer of the internal olefin methyl 3-phenyl-2-methylpropenoate is the E-isomer, whereas the only stereoisomer of the double arylated reaction product methyl 2-benzyl-3- phenylpropenoate is the Z-isomer. A DFT study, which investigates mechanistic aspects of migratory insertion, β-hydride elimination and reductive elimination of this phosphine-free Heck reaction, is in agreement with our experimental findings.
- Petrovi?, Zorica D.,Petrovi?, Vladimir P.,Simijonovi?, Du?ica,Markovi?, Svetlana
-
experimental part
p. 144 - 151
(2012/04/17)
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- Highly effective recyclable palladium-catalyzed ligand-free heck reactions under aerobic conditions
-
An effective protocol was developed for the Heck coupling reactions between various aryl halides and olefins. In the presence of 2 mol% of Pd(OAc) 2, the desired products could be obtained in good yields under ligand-free and aerobic conditions. The catalytic system could be easily recycled for five times with high efficiency. Georg Thieme Verlag Stuttgart. New York.
- Sun, Peng,Qu, Xiaoming,Li, Tingyi,Zhu, Yan,Yang, Hailong,Xing, Zeyong,Mao, Jincheng
-
supporting information; experimental part
p. 150 - 154
(2012/02/04)
-
- N-heterocyclic carbene catalyzed umpolung of Michael acceptors for intermolecular reactions
-
leahciM! The N-heterocyclic carbene catalyzed umpolung of Michael acceptors proceeds through the formation of a deoxy-Breslow intermediate (see scheme; EWG=electron-withdrawing group). This nucleophilic species can react with other Michael acceptors in an intermolecular fashion, thereby resulting in the formation of homo- or heterodimeric olefins. This "Michael umpolung" should become a valuable method for the formation of densely functionalized olefins.
- Biju, Akkattu T.,Padmanaban, Mohan,Wurz, Nathalie E.,Glorius, Frank
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p. 8412 - 8415
(2011/10/31)
-
- Ligand-free reusable palladium-catalyzed heck-type coupling reactions of hypervalent iodine reagents under mild conditions
-
Highly effective palladium-catalyzed Heck-type couplings of hypervalent iodine reagents are reported for the first time. It is noteworthy that such reactions could be carried out in the absence of ligand at 40 °C and the catalytic system could be easily reused for five times. Copyright
- Qu, Xiaoming,Sun, Peng,Li, Tingyi,Mao, Jincheng
-
supporting information; experimental part
p. 1061 - 1066
(2011/07/09)
-
- Fluorinated β2- and β3-amino acids: Synthesis and inhibition of α-chymotrypsin
-
The synthesis of a series of -fluorinated β2- and β3-amino acid derivatives is described. Stereoselective fluorination at the -carbon of the β3-amino acids was achieved by deprotonation with lithium diisopropylamide followed by treatment with N-fluorobenzenesulfonimide. Fluorination of β2-amino acids employed the chiral auxiliary (4R)-4-benzyl-2-oxazolidinone. The α-fluorinated amino acids and their non-fluorinated precursors were found to competitively inhibit α-chymotrypsin. Georg Thieme Verlag Stuttgart New York.
- Peddie, Victoria,Pietsch, Markus,Bromfield, Karen M.,Pike, Robert N.,Duggan, Peter J.,Abell, Andrew D.
-
body text
p. 1845 - 1859
(2010/10/18)
-
- Palladium(0) nanoparticle catalyzed cross-coupling of allyl acetates and aryl and vinyl siloxanes
-
(Chemical Equation Presented) The cross-coupling of allyl acetates and aryl and vinyl siloxanes proceeds readily by the catalysis of in situ generated palladium(0) nanoparticles. The reactions are stereoselective, and (E)-coupling products are obtained both from cis and trans allyl acetates. The coupling with vinyl siloxanes provides a novel protocol for the synthesis of 1,4-pentadienes.
- Dey, Raju,Chattopadhyay, Kalicharan,Ranu, Brindaban C.
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experimental part
p. 9461 - 9464
(2009/04/06)
-
- Radical-polar crossover domino reactions involving organozinc reagents and β-(allyloxy)-enoates
-
Organozinc reagents (organozinc halides, diorganozincs and mixed copper-zinc reagents) react with β-(allyloxy)-enoates via a radical-polar crossover process to afford substituted furans in one single synthetic step following a domino reaction involving Michael addition and carbocyclisation. Reversal of diastereoselectivity can be obtained varying the organometallic and/or the reaction conditions.
- Giboulot, Steven,Pérez-Luna, Alejandro,Botuha, Candice,Ferreira, Franck,Chemla, Fabrice
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p. 3963 - 3966
(2008/09/20)
-
- Discovery of potent HIV-1 protease inhibitors incorporating sulfoximine functionality
-
Based on the unique property of sulfoximine and the homodimeric C2 structural symmetry of HIV-1 protease, a novel class of sulfoximine-based pseudosymmetric HIV-1 protease inhibitors was designed and synthesized. The sulfoximine moiety was demonstrated to be important for HIV-1 protease inhibitor potency. The most active stereoisomer (2S,2′S) displays a potency of 2.5 nM (IC50) against HIV-1 protease and an anti-HIV-1 activity of 408 nM (IC50). A possible mode of action is proposed.
- Lu, Ding,Vince, Robert
-
p. 5614 - 5619
(2008/03/13)
-
- Substituted piperidine compounds and methods of their use
-
Certain 4-aryl-piperidine compounds, including N-substituted 9β-substituted-5-(3-substituted-phenyl)morphans and N-substituted octahydro-4a-(3-hydroxyphenyl)-10a-methyl-benzo[g]isoquinolines, pharmaceutical compositions, and methods of their use, inter alia, as opioid antagonists are disclosed.
- -
-
Page/Page column 25-26
(2008/06/13)
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- Tetraphosphine/palladium-catalyzed Heck reactions of aryl halides with disubstituted alkenes
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cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/ [PdCl(C3H5)]2 efficiently catalyses the Heck reaction of disubstituted alkenes such as methyl crotonate, ethyl cinnamate, methyl methacrylate or α-methylstyrene with a variety of aryl halides. In the presence of 1,2-disubstituted alkenes the stereoselectivities of the reactions strongly depend on the substituents of the alkenes. Selectivities up to 97% in favor of E-isomers can be obtained for the addition to methyl crotonate. With the 1,1-disubstituted alkenes methyl methacrylate or α-methylstyrene mixtures of products are obtained.
- Kondolff, Isabelle,Doucet, Henri,Santelli, Maurice
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p. 8487 - 8491
(2007/10/03)
-
- (α-aminophosphino) peptide derivatives, method for making same and therapeutic applications thereof
-
The invention concerns compounds derived from (α-aminophosphino) peptides, of general formula (I), in which R1and R2each represents a hydrogen atom or taken together form an imine with the adjacent nitrogen atom; R3represents an alkyl group, an alkenyl group, a phenyl group, a benzyl group, all these groups capable of being substituted or not, a hydrogen atom, a cycloalkyl group, a cycloalkylmethyl group or finally, a methyl group substituted by a heterocyclic, aromatic or saturated group; R4represents a phenyl group, a benzyl group, these groups capable of being substituted or not, a hydrogen atom, an alkyl group, analkenyl group or a cycloalkyl group; R5represents an alkyl group, an alkenyl group, a phenyl group, a benzyl group, all these groups capable of being substituted or not, a hydrogen atom, a cycloalkyl, cycloalkylmethyl group or finally a methyl group substituted by a heterocyclic, aromatic or saturated group; R6, R7and R8can in particular represent a hydrogen atom, an alkyl group, a phenyl group substituted or not . . . n is equal to 0 or 1, in the form of enantiomers, diastereoisomers or racemic mixtures, their salts, their method of preparation and their therapeutic applications.
- -
-
-
- Enantioselective synthesis of phosphinyl peptidomimetics via an asymmetric Michael reaction of phosphonic acids with acrylate derivatives
-
Asymmetric Michael reaction of phosphinic or aminophosphinic acids with acrylate derivatives afforded phosphinyl dipeptidomimetics in excellent yields (>90 percent). Chiral induction of substituents at the α-position of acrylate derivatives of Evans oxazolidinone type auxiliaries was obtained in moderate to excellent diastereomeric and enantiomeric excesses (50-98 percent). Pure diastereomers and enantiomers of phosphinyl dipeptidomimetics 16-19 were also successfully separated by HPLC.
- Lui, Xuewei,Hu, Eric,Tian, Xinrong,Mazur, Adam,Ebetino, Frank H.
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p. 212 - 222
(2007/10/03)
-
- Preparation of phosphinodipeptide analogs as building blocks for pseudopeptides synthesis
-
A simple and effective preparation of phosphinodipeptides, in good overall yields, has been developed. This one pot procedure, allowing the variation of the substituents in α and/or β position to the phosphorus atom and also in α position to the nitrogen atom, consists in the addition of alkyl hypophosphites to imines, followed by Michael-addition on acrylates. To show the value of phosphinodipeptides analogs 1 as synthetic intermediates, selective deprotections of the three functional groups are described.
- Cristau, Henri-Jean,Coulombeau, Agnès,Genevois-Borella, Arielle,Sanchez, Frédéric,Pirat, Jean-Luc
-
p. 381 - 391
(2007/10/03)
-
- The Baylis-Hillman chemistry in aqueous media: A convenient synthesis of 2-methylenealkanoates and alkanenitriles
-
A convenient, general and efficient synthesis of 2-methylenealkanoates and alkanenitriles is accomplished via the regioselective nucleophilic (SN2′) addition of hydride ion from NaBH4 to (2Z)-2-(bromomethyl)alk-2-enoates and 2-(bromomethyl)alk-2-enenitriles respectively in the presence of DABCO in environment friendly aqueous media. Synthesis of two hypoglycemic agents is also described.
- Basavaiah, Deevi,Kumaragurubaran, Nagaswamy
-
p. 477 - 479
(2007/10/03)
-
- Design and synthesis of isoxazoline derivatives as factor Xa inhibitors. 2
-
Intravascular clot formation is an important factor in a number of cardiovascular diseases. Therefore, the prevention of blood coagulation has become a major target for new therapeutic agents. One attractive approach is the inhibition of factor Xa (FXa),
- Quan, Mimi L.,Ellis, Christopher D.,Liauw, Ann Y.,Alexander, Richard S.,Knabb, Robert M.,Lam, Gilbert,Wright, Matthew R.,Wong, Pancras C.,Wexler, Ruth R.
-
p. 2760 - 2773
(2007/10/03)
-
- Palladium catalysed regio and stereoselective reduction of Baylis- Hillman coupling products derived allylic acetates
-
Acetates derived from a variety of the Baylis-Hillman products undergo reduction with HCOOH in the presence of Et3N, Pd(OAc)2, and dppe (or tri- isopropylphosphite) to yield the corresponding trisubstituted Z-olefins in good yields d
- Pachamuthu, Kandaswamy,Vankar, Yashwant D.
-
p. 5439 - 5442
(2007/10/03)
-
- Subsituted 4-(2-alkenylsulfinyl)morpholines : preparation and conversion into the corresponding sulfinic acids and esters. Stereochemistry of olefin formation by hydrolytic desulfinylation of allylic sulfinamides.
-
By reaction with 4-(chlorosulfenyl)morpholine in the presence of triethylamine, several substituted allylic alcohols have been converted into the title sulfinamides.As a complementary method, the new α-lithio allylic sulfinamides have been prepared and efficiently alkylated with organic halides.The boron trifluoride-etherate catalyzed treatment of the allylic sulfinamides with simple saturated alcohols provided the corresponding alkyl sulfinates while propargylic and allylic alcohols opened a route to various α,α'-bis-unsaturated sulfones.Efficient conditions for the acid-catalyzed hydrolysis of allylic sulfinamides are described and some allylic sulfinic acids bearing an electron-withdrawing group were isolated.Smooth fragmentation of the homoconjugated sulfinic acids gave the corresponding (E)-olefins stereoselectively. - Key words: sigmatropic rearrangement / allylic sulfinamide / allylic sulfinic ester / organolithium derivative / sulfone / retro-ene reaction / sulfur dioxide elimination / stereochemistry
- Baudin, Jean-Bernard,Julia, Sylvestre
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p. 196 - 214
(2007/10/02)
-
- Palladium-catalyzed cross-coupling of aryl and alkenyl boronic acids with alkenes via oxidative addition of a carbon-boron bond to palladium(0)
-
Arylboronic acids react with alkenes in acetic acid at 25 deg C in the presence of a catalytic amount of palladium(II) acetate together with sodium acetate to give the corresponding aryl-substituted alkenes in high yields.Alkenylboronic acids react with alkenes under similar conditions to give the corresponding conjugated dienes stereospecifically, but the product yields are lower, compared with those from arylboronic acids.Similar treatment of sodium tetraphenylborate (NaBPh4) with alkenes also affords the corresponding phenylated alkenes in high yields together with biphenyl and benzene as side products.Oxidative addition of a carbon-boron bond to palladium(0), formed in situ, to give an organopalladium(II) species is assumed to be the key step of these cross-coupling reactions. Key words: Boronic acid; Aryl; Alkenyl; Alkene; Palladium; Oxidative addition
- Cho, Chan Sik,Uemura, Sakae
-
-
- Elimination of β-palladium hydroxide in the PdII-catalyzed reaction of methyl(α-hydroxymethyl)acrylate with alcohols
-
Exclusive elimination of β-Pd-OH takes place in the oxypalladation intermediate derived from methyl(α-hydroxymethyl)acrylate and alcohols with PdCl2 catalyst, and no β-Pd-H elimination occurs. Key words: Palladium; Hydroxide; Catalysis; Alkene; Mechanism
- Hosokawa, Takahiro,Sugafuji, Toshihiro,Yamanaka, Toshio,Murahashi, Shun-Ichi
-
p. 253 - 256
(2007/10/02)
-
- Studies directed toward the design of orally active renin inhibitors. 2. Development of the efficacious, bioavailable renin inhibitor (2S)-2-benzyl- 3-[[(1-methylpiperazin-4-yl)sulfonyl]propionyl]-3-thiazol-4-yl-L-alanine amide of (2S,3R,4S)-2-amino-1-cyc
-
Employing a set of empirical guidelines for the design of well-absorbed renin inhibitors, we have followed two strategies to improve potency while maintaining bioavailability. One process involved incorporation of an extended N-terminal residue bearing a
- Rosenberg,Spina,Condon,Polakowski,Yao,Kovar,Stein,Cohen,Barlow,Klinghofer,Egan,Tricarico,Perun,Baker,Kleinert
-
p. 460 - 467
(2007/10/02)
-
- Peptidyl difluorodiol renin inhibitors
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A renin inhibiting compound of the formula: wherein A is a functional group; W is (1)-C(O)-,(2)-CH(OH)-or(3)-N(R?)-wherein R? is hydrogen or loweralkyl; U is (1)-C(O)-,(2)-CH?-or(3)-N(R?)-wherein R? is hydrogen or lower alkyl, with the proviso that when W is-CH(OH)-then U is-CH?-and with the proviso that U is-C(O)-or-CH?-when W is-N(R?)-; V is (1)-CH-,(2)-C(OH)-or(3)-C(halogen)-with the proviso that v is-CH--when U is-N(R?)-; Q is-CH(R?)-or-C(=CHR1a)-wherein R? is (1) loweralkyl,(2) cycloalkylalkyl,(3) arylalkyl,(4) (heterocyclic) alkyl,(5) 1-benzyloxyethyl,(6) phenoxy,(7) thiophenoxy or(8) anilino, provided that B is-CH?-or-CH(OH)-or A is hydrogen when R? is phenoxy, thiophenoxy or anilino and R1a is aryl or heterocyclic; R? is a functional group; R? is (1) loweralkyl,(2) cycloalkylmethyl or(3) benzyl; R? is-CH(OH)-or-C(O)-; R? is-CH(OH)-or-C(O)-; and Z is (1) lower alkyl,(2) aryl,(3) arylalkyl,(4) cycloalkyl,(5) cycloalkylalkyl,(6) heterocyclic or(7) (heterocyclic)alkyl; or a pharmaceutically acceptable salt, ester or prodrug thereof.
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- PEPTIDYL AMINODIOL RENIN INHIBITORS
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A renin inhibiting compound having an aminodiol functional group is useful for treating hypertension, congestive heart failure and glaucoma and inhibits retroviral protease.
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- Novel amino acid derivatives possessing renin-inhibitory activities
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An amino acid derivative of the general formula: wherein, R1? is a lower alkyl group and R11 is (wherein R111 is a lower alkyl group and n is an integer of 1 to 5) or a lower alkyl group which may be substituted by hydroxy group or methoxyethoxymethoxy group, or R1? and R11 are combinedly together with the adjacent nitrogen atom; R12 is a hydrogen atom, CnH2n+ 1-O-CO-(n is as defined above) or R13 is a lower alkyl group which may be substituted by substituent(s) selected from HOOC-(H?C)n-O-, R12-NH-(n and R12 are as defined above) and pyridyl group; X is-CH?-,-O-or-NH-and Y is-O-or-NH-; wherein (wherein Z is-O-,-S-,-S(O)-,-S(O)?-,-CH?-,-CH(OH)-,---,-NH-or and a and b are independently an integer of 1 to 4 and the total of a and b is not more than 5) ; R2 is an aralkyl group which may be substituted by lower alkyl group(s); R3 is a hydrogen atom or a lower alkyl group; R? is a lower alkyl group; and A is hydroxy group and B is a hydrogen atom, or A and B are carbonyl group combinedly together with the adjacent carbon atom, a pharmaceutically acceptable acid addition salt or an ester thereof is described. The compounds of the invention possess inhibitory activities against renin and are useful as an antihypertensive agent.
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- Renin-inhibiting functionalized peptidyl aminodiols and - triols
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A renin inhibiting compound of the formula: or a pharmaceutically acceptable salt, ester or prodrug thereof.
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- SIMPLE SYNTHESIS OF α-METHYLENE ESTERS AND AMIDES FROM METHACRYLIC DERIVATIVES VIA TOSYLATED INTERMEDIATES
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α-(Tosylmethyl)acrylic acid methyl ester or N-isopropylamide (obtained by a tandem iodosulfonylation-dehydroiodination of methyl methacrylate or N-isopropylacrylamide) react with Grignard reagents or sodium diethyl malonate to give the corresponding α-met
- Najera, Carmen,Mancheno, Balbino,Yus, Miguel
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p. 3837 - 3840
(2007/10/02)
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- Renin-inhibiting peptidyl heterocycles
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A renin inhibiting compound of the formula:*(formula 01)* wherein A is a substituent; W is C=O, CHOH or NR2 wherein R2 is hydrogen or loweralkyl; U is C=O, CH2 or NR2 wherein R2 is hydrogen or loweralkyl, with the proviso that when W is CHOH then U is CH2 and with the proviso that U is C=O or CH2 when W is NR2; V is CH, C(OH) or C(halogen) with the proviso that V is CH when U is NR2; R1 is loweralkyl, cycloalkylalkyl, benzyl, (alpha, alpha)-dimethylbenzyl, 4-methoxybenzyl, halobenzyl, 4-hydroxybenzyl, (1-naphthyl)methyl, (2-naphthyl)methyl, (unsubstituted heterocyclic)methyl, (substituted heterocyclic)methyl, phenethyl, 1-benzyloxyethyl, phenoxy, thiophenoxy or anilino, provided that B is CH2 or CHOH or A is hydrogen when R1 is phenoxy, thiophenoxy or anilino; R3 is loweralkyl, loweralkenyl, ((alkoxy)alkoxy)alkyl, carboxyalkyl, (thioalkoxy)alkyl, azidoalkyl, aminoalkyl, (alkyl)aminoalkyl, dialkylaminoalkyl,(alkoxy)(alkyl)aminoalkyl, (alkoxy)aminoalkyl, benzyl or heterocyclic ring substituted methyl; R4 is loweralkyl, cycloalkylmethyl or benzyl; R5 is OH or NH2; and Z is a substituent. Also disclosed are compositions for and a method of treating hypertension, methods of making the renin inhibiting compounds and intermediates useful in making the renin inhibiting compounds.
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- UNSATURATED SULFINAMIDES III. CONVERSION OF SEVERAL 4-(2'-ALKENESULFINYL)-MORPHOLINES INTO THE CORRESPONDING SULFINATE ESTERS, UNSYMMETRICAL BISALLYLIC SULFONES AND OLEFINS. ISOLATION OF SOME FUNCTIONALISED 2-ALKENESULFINIC ACIDS.
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The boron trifluoride etherate-catalysed treatment of the unsaturated sulfinamides (1a-e) with simple saturated alcohols afforded the corresponding alkyl sulfinates 2 whereas allylic alcohols provided the bisallylic sulfones 4.Efficient conditions for the acid-catalysed hydrolysis of the unsaturated sulfinamides 1 are described and some allylic sulfinic acids bearing an electronwithdrawing group 6 were isolated.Smooth fragmentation of the homoconjugated sulfinic acids gave the corresponding olefins 5 and 7.
- Baudin, Jean-Bernard,Julia, Sylvestre A.
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p. 3255 - 3258
(2007/10/02)
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- Methyl 4-Oxothiolane-3-carboxylate and Methyl 2-Methyl-4-oxothiolane-3-carboxylate Anions as Synthetic Equivalents of α-Acrylate and α-Crotonate Anions. Formal Synthesis of Integerrinecic Acid
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The base-promoted fragmentation of the C-alkylation products (6a-h) and (8a-e) of methyl 4-oxothiolane-3-carboxylate (4) and methyl 2-methyl-4-oxothiolane-3-carboxylate (5) gave good yields of the α-substituted acrylates (7a-h) and α-substituted crotonate
- Baraldi, Pier Giovanni,Guarneri, Mario,Pollini, Gian Piero,Simoni, Daniele,Barco, Achille,Benetti, Simonetta
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p. 2501 - 2505
(2007/10/02)
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- A Novel α-Acrylate Anion Equivalent: A Useful Synthon for α-Substituted Acrylic Esters
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An efficient preparation of α-substituted acrylic esters is described, based on the Dieckmann-Michael retrograde reactions of the C-alkylation products of 4-methoxycarbonylthiolan-3-one (1).
- Baraldi, Pier Giovanni,Barco, Achille,Benetti, Simonetta,Moroder, Fabio,Pollini, Gian Piero,et al.
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p. 1265 - 1266
(2007/10/02)
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- STEREOCHEMICAL COURSE OF THE PALLADIUM-CATALYSED ARYLATION OF DISUBSTITUTED ACTIVATED ALKENES WITH BENZOYL CHLORIDE
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The palladium-catalysed arylation of ten 1,1- and 1,2-disubstituted activated alkenes with benzoyl chloride was studied.In most cases, more than one product was formed.The stereochemical course of the arylation appears to be controlled by the polarity of
- Spencer, Alwyn
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p. 209 - 216
(2007/10/02)
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- Doubly Deprotonated Methyl 3-Nitropropanoate, an Acrylic Ester d2-Reagent
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Methyl 3-nitropropanoate can be doubly deprotonated with LDA, both in the α-nitro and in the α-carbonyl position (-> 1).It is shown that the necessary cosolvent HMPT can be replaced by the cyclic urea DMPU, with almost equal results.The new reagent 1 is alkylated and hydroxyalkylated by alkyl halides and aldehydes, respectively, at the 2-position exclusively (see 2, 4, 6, 7).A double alkylation to methyl α,α-dialkyl-β-nitropropanoate 5 is possible.Elimination of HNO2 with DBN or even better with DBU in THF furnishes methyl α-methylenealkanoates 9 and methyl β-hydroxy-α-methylenealkanoates 10.
- Seebach, Dieter,Henning, Rainer,Mukhopadhyay, Triptikumar
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p. 1705 - 1720
(2007/10/02)
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