- The Allylic Acetoxylation of 1,1-Disubstituted Alkenes Catalyzed by a Palladium(II)/Monothiadiazole Ligand System
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A palladium(II)/monothiadiazole ligand catalytic system and its application in catalyzing the acetoxylation of 1,1-disubstituted alkenes have been developed. With this newly designed monothiadiazole thioether ligand, the reaction showed a broad scope with respect to 1,1-disubstituted olefins, giving the corresponding products in yields of 30-86percent.
- Jin, Can,Li, Xiaohan,Sun, Bin,Wang, Jiayang,Yang, Jin,Yu, Chuangming,Zhang, Xun,Zhuang, Xiaohui
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supporting information
p. 1479 - 1483
(2019/07/15)
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- Formyloxyacetoxyphenylmethane and 1,1-diacylals as versatile O-formylating and O-acylating reagents for alcohols
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Formyloxyacetoxyphenylmethane, symmetric 1,1-diacylals and mixed 1-pivaloxy-1-acyloxy-1-phenylmethanes have been used as moisture stable O-formylating and O-acylating reagents for primary and secondary alcohols, allylic alcohols and phenols under solvent/catalyst free conditions to afford their corresponding esters in good yield.
- Chapman, Robert S.L.,Francis, Molly,Lawrence, Ruth,Tibbetts, Joshua D.,Bull, Steven D.
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p. 6442 - 6452
(2018/10/02)
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- Heteropoly acid catalysts for the synthesis of fragrance compounds from bio-renewables: Acetylation of nopol and terpenic alcohols
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The cesium salt of tungstophosphoric heteropoly acid, Cs2.5H0.5PW12O40, is an active and environmentally friendly heterogeneous catalyst for the liquid-phase acetylation of nopol and several biomass-derived terpenic alcohols (i.e., α-terpineol, nerol, geraniol, linalool, menthol, isoborneol, perillyl alcohol, carveol, isopulegol, carvacrol and nerolidol) with acetic anhydride. The resulting flavor and fragrance acetic esters, which are widely used in perfumery, household and food products, are obtained in good to excellent yields. The reactions occur at room temperature with low catalyst loadings without substantial catalyst leaching and can be performed with stoichiometric amounts of an acetylating agent in solvent free systems.
- Costa, Vinicius V.,Da Silva Rocha, Kelly A.,Oliveira, Luiz C. A.,Kozhevnikova, Elena F.,Kozhevnikov, Ivan V.,Gusevskaya, Elena V.
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p. 43217 - 43222
(2016/05/24)
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- Pd(OAc)2/M(NO3)n (M = Cu(II), Fe(III); n = 2, 3): Kinetic investigations of an alternative Wacker system for the oxidation of natural olefins
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Pd-catalyzed oxidative coupling of camphene by dioxygen afforded mainly a diene, which subsequently underwent oxidation to a ring-expanded β,γ-unsaturated ketone with LiNO3 as reoxidant. However, the instability of LiNO3 results to t
- da Silva, Márcio J.,Teixeira, Róbson Ricardo,Carari, Danielli Marcolan
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scheme or table
p. 3254 - 3261
(2010/01/11)
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- Process for making terpene esters
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A process for making terpene esters is disclosed. Reaction of a terpene alcohol with acetic anhydride in the presence of a high-boiling amine provides a terpene ester. Acetic acid, which is distilled from the reaction mixture as it forms can be recovered. The terpene ester is distilled from the high-boiling amine to provide a product that is substantially free of nitrogen-containing impurities. The reaction mixture can be reused for subsequent acylations. The simple, economical process gives high-quality terpene esters while avoiding waste-disposal issues of other common acylation procedures.
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Page/Page column 6
(2008/06/13)
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- Enantiomeric differentiation of oxygenated p-menthane derivatives by 13C NMR using Yb(hfc)3
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The 13C NMR behaviour of 21 p-menthanic terpene bearing an oxygenated function (alcohol, ketone, acetate) was examined in the presence of a chiral lanthanide shift reagent (Yb(hfc)3). For each monocyclic compound, we measured the lanthanide-induced shift (LIS) on the signals of the carbons and the splitting of signals allowing the enantiomeric differentiation. Some general features were found about their LIS behaviour: experimental data establishing distinct patterns for carvomenthone-like compounds and menthone-like compounds. The enantiomeric splitting was observed for the majority of signals in the spectrum of each compound. In the case of alcohols and acetates, the influence of the relative stereochemistry (cis vs trans) of isopropyl(ene) and the binding function was discussed. Copyright
- Lanfranchi, Don Antoine,Blanc, Marie-Cecile,Vellutini, Muriel,Bradesi, Pascale,Casanova, Joseph,Tomi, Felix
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experimental part
p. 1188 - 1194
(2009/05/26)
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- Palladium catalyzed oxidation of monoterpenes: NMR study of palladium(II)-monoterpene interactions
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Reactions of the monoterpenes β-pinene, limonene and myrcene with Pd(II) complexes in acetic acid solutions were studied by 1H NMR spectroscopy. Various π-allyl palladium complexes were detected in situ and their interaction with CuCl2 has been investigated. The results clarify the mechanism of allylic oxidation of these substrates mediated by Pd(II)/Cu(II)-based catalytic systems. Originally introduced to regenerate reduced palladium species, CuCl2 has been shown to play an important role in the formation and/or decomposition of key reaction intermediates - π-allyl palladium complexes. β-Pinene and myrcene readily react with Pd(OAc)2 giving corresponding π-allyls, with two complexes acyclic and cyclic being formed from myrcene. On the other hand, the formation of π-allyl complexes from limonene occurs at a significant rate only in the presence of CuCl2. NMR observations, including selective paramagnetic enhancement of spin-lattice relaxation, indicate that π-allyl palladium intermediates specifically interact with Cu(II) ions in the reaction solutions. Such interaction probably involves Cu(II) bonding to Pd(II) via bridging ligands, and seems to be responsible for the accelerative effect of CuCl 2 in the palladium catalyzed oxidation of the monoterpenes. Indeed, most of these reactions do not occur at all in the absence of CuCl2.
- Gon?alves, José Ailton,Da Silva, Márcio José,Piló-Veloso, Dorila,Howarth, Oliver W.,Gusevskaya, Elena V.
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p. 2996 - 3003
(2007/10/03)
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- Oxidative esterification of alkenes via π- and σ-organopalladium complexes: New pathways for the reaction
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New mechanistic data on the oxidative esterification of alkenes were obtained in the study of the reaction of Pd(II) acetate with hex-1-ene, methylcyclohex-1-ene and racemic α-pinene in a chloroform solution. High yields of unsaturated esters with terminal alcohol group were found in the oxidation of hex-1-ene, while the exocyclic methyl groups in methylcyclohex-1-ene and α-pinene remain untouched.
- Kozitsyna, N.Yu.,Bukharkina,Martens,Vargaftik,Moiseev
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- Iodine as an Acetyl Transfer Catalyst
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Iodine catalyses the acetylation of amines, phenols and alcohols, including tertiary ones, with acetic anhydride in excellent yield.
- Borah, Ruli,Deka, Nabajyoti,Sarma, Jadab C.
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p. 110 - 111
(2007/10/03)
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- Cobalt(II)-Catalyzed Conversion of Allylic Alcohols/Acetates to Allylic Amides in the Presence of Nitriles
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Various secondary allylic alcohols or their acetates and tertiary allylic alcohols can be converted to the corresponding transposed allylic amides in the presence of a catalytic quantity of cobalt(II) chloride and acetic anhydride in acetonitrile.Tertiary alcohols undergo complete rearrangement whereas secondary ones afford a mixture of regioisomers.Moderate yields of amides are also obtained by reacting acrylonitrile with secondary alcohols in 1,2-dichloroethane.The presence of acetic anhydride or acetic acid is crucial to the formation of amides as the absence of the former affords no amides and the allylic alcohols are mainly recovered as regioisomeric mixtures.The regioselectivity during amide formation can be enhanced by using cobalt complexes 14-16 in acetic acid medium.Some preliminary studies indicate that these reactions are proceeding via an ?-allyl complex or tight ion pair rather than a sigmatropic rearrangement of acetamidate obtained in a Pinner reaction.
- Mukhopadhyay, Manoj,Reddy, M. Madhava,Maikap, G. C.,Iqbal, Javed
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p. 2670 - 2676
(2007/10/02)
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- COBALT(II) CHLORIDE CATALYSED CONVERSION OF ALLYLIC ALCOHOLS TO REARRANGED ALLYLIC AMIDES
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Secondary and tertiary allylic alcohols can be converted to the corresponding allylically rearranged amides and acetates in presence of a catalytic quantity of cobalt(II) chloride and acetic anhydride in acetonitrile.Tertiary alcohols undergo complete rearrangement whereas the secondary ones yield a mixture of regioisomers.
- Nayyar, Naresh K.,Reddy, M. Madhava,Iqbal, Javed
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p. 6965 - 6968
(2007/10/02)
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- FACILE FRAGMENTATION OF PINENES USING DIMETHYL SULFOXIDE ACTIVATED BY PHENYL DICHLOROPHOSPHATE OR PHOSPHORUS OXYCHLORIDE. EFFICIENT CONVERSION OF α-PINENE TO CARVONE
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Treatment of pinenes with dimethyl sulfoxide in the presence of phenyl dichlorophosphate or phosphorus oxychloride resulted in facile fragmentation giving rise to limonene derivatives.The fragmentation reaction serves as a key step in the efficient conversion of α-pinene (1) to carvone (7).
- Liu, Hsing-Jang,Nyangulu, James M.
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p. 5097 - 5098
(2007/10/02)
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- Microbial Allyl Rearrangement and Resolution of Acetates of Unsaturated Cyclic Terpene Alcohols by Pseudomonas sp. NOF-5 Strain
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Microbial hydrolysis of the acetates of unsaturated cyclic terpene alcohols by Pseudomonas sp.NOF-5 isolated from soil was investigated. (+/-)-trans-Carveyl acetate ((+/-)-trans-3) was enantioselectively hydrolyzed with NOF-5 strain to give (-)-trans-carveol ((-)-trans-2 of 86.6percent optical purity).However, the hydrolysis of (+/-)-cis-3 was less enantioselective, while (+/-)-piperitylacetate ((+/-)-6, a cis and trans mixture) was hydrolyzed to give the (-)-trans- and (-)-cis-piperitols ((-)-trans-5 and (-)-cis-5) in a poor optical yield.In this case, other tert-alcohols, (+)-trans- and (-)-cis-2-p-menthen-1-ols ((+/-)-trans-7 and (-)-cis-7, were also produced.Furthermore, microbial and enzymic allyl rearrangements of (+)-trans-6 and (-)-trans-verbenylacetate ((-)-trans-11) were studied.Biological treatment of (+)-trans-6 and (-)-trans-11 with NOF-5 or its esterase gave (+)-trans- and (-)-cis-7 and (+)-cis-3-pinen-2-ol ((+)-cis-12), respectively.
- Inagaki, Takashi,Ueda, Hiroo
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p. 2635 - 2640
(2007/10/02)
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- Reactions of d-Limonene with t-Butyl Hypochlorite
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Investigation of the title reaction under different conditions of temperature, solvents and catalysis has led to its optimisation with respect to the yield of (-)-trans-carvyl chloride (2).Other products formed in the reaction have been identified as 1,2-dichloro-p-menth-8-ene (5), 10-chloro-p-mentha-1,8-diene (6), 2-chloro-p-mentha-1(7)8-diene (10) and 6,10-dichloro-p-mentha-1,8-diene (11).The reaction proceeds almost entirely by electrophilic halogenation with no evidence of competition from a radical mechanism.
- Ravindranath, B.,Srinivas, P.
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p. 163 - 165
(2007/10/02)
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- Some Novel Esters of Carveol
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Reaction of limonene (1) with t-butyl hypochlorite yields carvyl chloride as the major product, which is readily converted into carvyl acetate, carveol and carvone.Several novel esters of carveol, namely cis and trans carvyl benzoate, cinnamate, phenoxyacetate and phenylacetate have also been prepared for the first time in a one-pot reaction of carvyl chloride with the corresponding zinc carboxylate.
- Ravindranath, B.,Srinivas, P.
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p. 666 - 667
(2007/10/02)
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- NUCLEOPHILIC SUBSTITUTION OF ALKYL HALIDES BY ZINC SALTS-3 PREPARATION OF TERTARY ALKYL ESTERS AND ETHERS UNDER NON-SOLVOLYTIC CONDITIONS
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Zinc salts of carboxylic acids, phenols and alcohols are found to react with tertiary alkyl halides in nonpolar solvents and in presence of a base yielding the corresponding esters and ethers in moderate to good yields.
- Ravindranath, B.,Srinivas, P.
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p. 1623 - 1628
(2007/10/02)
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- SOLVOLYTIC DISPLACEMENT OF ALKYL HALIDES BY METAL SALTS. PREPARATIVE PROCEDURES FOR ALLYL-, BENZYL- AND TERTIARY ALKYL-OXY DERIVATIVES USING THE ZINC SALTS
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Reaction of allylic, benzylic and tertiary alkyl halides with zinc oxide in protic solvents leads to the formation of the corresponding alcohols, ethers and esters in good yields.The scope and limitations of this reaction have been examined.The possible involvement of ion quadruplets in the reaction is suggested.
- Gurudutt, K. N.,Ravindranath, B.,Srinivas, P.
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p. 1843 - 1846
(2007/10/02)
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- Enzymic Resolution of (+/-)-Unsaturated Cyclic Terpene Alcohols via Asymmetric Hydrolysis of Corresponding Acetates by Microorganisms
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Asymmetric hydrolysis of the acetates of (+/-)-cis and trans-carveols by microorganisms or their esterase produced chiral cis and trans-carveols and the acetates of their enantiomers.The enantioselectivity of the microbial hydrolysis and the optical purities of the products varied with the species of microorganisms.This method was also applied in separation of diastereomeric mixtures of (-)-carveols and (-)-7-epi-α-cyperols.
- Oritani, Takayuki,Yamashita, Kyohei
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p. 2637 - 2642
(2007/10/02)
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