65416-24-2Relevant articles and documents
Copper-catalyzed enantioselective carbenoid insertion into S-H bonds
Zhang, Yong-Zhen,Zhu, Shou-Fei,Cai, Yan,Mao, Hong-Xiang,Zhou, Qi-Lin
, p. 5362 - 5364 (2009)
An asymmetric carbenoid insertion into S-H bonds catalyzed by copper-chiral spiro bisoxazoline complexes has been developed, in which a series of α-mercaptoesters were produced in high yields with moderate to good enantioselectivities (up to 85% ee); this
Electrochemical anion pool synthesis of amides with concurrent benzyl ester synthesis
Mevan Dissanayake,Melville, Alex D.,Vannucci, Aaron K.
supporting information, p. 3165 - 3171 (2019/06/18)
An electrosynthesis method for amide bond formation has been developed in an attempt to increase the atom economy for this class of reactions. This "anion pool" method electrochemically generates strong nucleophiles from amine substrates. The amine nucleophiles then react with acid anhydrides to generate amides, and the by-product from this reaction undergoes further chemical transformations to generate pharmaceutically relevant benzoic esters. These one-pot reactions are operationally simple, are performed at room temperature, and avoid rare transition metals and added bases. The amide synthesis is amenable to primary and secondary amines and a variety of anhydrides with yields up to 90% obtained. Atom economy and process mass index (PMI) values calculated for this procedure indicate that this process can be considered greener compared to traditional amide synthesis routes used by industry. Furthermore, this electrochemical approach showed unique selectivity when substrates that contained two inequivalent amine moieties were examined.
Carboxylative Suzuki coupling reactions of benzyl chlorides with allyl pinacolborate catalyzed by palladium nanoparticles
Sun, Jian,Wang, Jiasheng,Feng, Xiujuan,Yamamoto, Yoshinori,Almansour, Abdulrahman I.,Arumugam, Natarajan,Kumar, Raju Suresh,Bao, Ming
, p. 1258 - 1262 (2018/06/21)
Palladium-catalyzed carboxylative Suzuki coupling reactions of benzyl chlorides with allyl pinacolborate were successfully conducted in the absence of any extra ligand to produce β,γ-unsaturated esters in satisfactory to good yields. The carboxylative Suzuki coupling reaction proceeded smoothly under mild conditions in the presence of palladium nanoparticles generated in situ through the formation of a π-benzylpalladium chloride intermediate.
Chemoselective Transesterification of Acrylate Derivatives for Functionalized Monomer Synthesis Using a Hard Zinc Alkoxide Generation Strategy
Nakatake, Daiki,Yazaki, Ryo,Ohshima, Takashi
supporting information, p. 3696 - 3699 (2016/08/20)
A new practical method for the synthesis of functionalized acrylate derivatives with the view to prepare functional polymers was explored. Hard zinc alkoxide generation enabled the highly chemoselective transesterification of acrylate derivatives over the undesired conjugate addition, which caused polymerization. The combined use of the catalytic zinc cluster Zn4(OCOCF3)6O and 4-(dimethylamino)pyridine delivered various functionalized acrylate derivatives through the transesterification of commercially available methyl acrylate derivatives with functionalized alcohols under mild conditions.
Use of diethoxymethane as a solvent for phase-transfer esterification of carboxylic acids
Coleman, M. Todd
scheme or table, p. 1911 - 1913 (2012/06/04)
The esterification of carboxylic acids with selected primary alkyl halides in diethoxymethane (DEM) utilizing solid-liquid phase-transfer catalysis has been studied. The use of DEM as the solvent simplifies the process in that a single solvent can be used for both reaction and workup.
Well-defined binuclear chiral spiro copper catalysts for enantioselective N-H insertion
Zhu, Shou-Fei,Xu, Bin,Wang, Guo-Peng,Zhou, Qi-Lin
supporting information; experimental part, p. 436 - 442 (2012/03/07)
An asymmetric N-H insertion of α-diazoesters with anilines catalyzed by well-defined copper complexes of chiral spiro bisoxazoline ligands was studied in detail. The copper-catalyzed asymmetric N-H insertion of a wide range of α-alkyl-α-diazoacetates with anilines was accomplished with excellent enantioselectivity (up to 98% ee) and provided an efficient method for the preparation of optically active α-amino acid derivatives. A correlation study of the electronic properties of the substrates with the enantioselectivity of the N-H insertion reaction supports a stepwise insertion mechanism, and the significant first-order kinetic isotope effect proves that the proton transfer is most likely the rate-limiting step. A binuclear chiral spiro copper catalyst having 14-electron copper centers, a trans coordination model, a perfect C2-symmetric chiral pocket, and significant Cu-Cu interaction was isolated and extensively studied. The novel structure of the binuclear chiral spiro copper catalyst leads to unique reactivity as well as enantioselectivity in the N-H insertion reaction.
Scalable synthesis of enantiomerically pure syn -2,3-dihydroxybutyrate by sharpless asymmetric dihydroxylation of p -phenylbenzyl crotonate
Smaltz, Daniel J.,Myers, Andrew G.
body text, p. 8554 - 8559 (2011/12/03)
An efficient four-step synthetic route to the useful chiral building block (2R,3S)-dihydroxybutyric acid acetonide in >95% ee is detailed. The sequence is readily scaled, requires no chromatography, and allows for efficient recycling of p-phenylbenzyl alcohol, an expedient for enantio- and diastereoenrichment by recrystallization.
PREPARATION OF ALKENES BY MILD THERMOLYSIS OF SULFOXIDES
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Page/Page column 5, (2010/07/02)
Embodiments of this disclosure, among others, encompass methods for generating alkenes under mild thermolytic conditions that can provide almost total conversion of a precursor compound to an alkene without isomerization or the need to chromatographically purify the final product By selectively blocking the amino and carboxy groups of the depvatized amino acid, the methods of the disclosure provide for the synthesis of a peptide having the vinylglycine moiety at either the carboxy or the amino terminus of the peptide The mild conditions for the thermolytic removal of an o-NO2-phenyl substituted aryl group ensure that there is minimal if any damage to thermally sensitive conjugates such as a peptide bearing the vinylglycine The methods of the present disclosure have practical applications for the preparation of unsaturated compounds under mild, thermolytic conditions.
The effect of fluoromethyl groups on the diastereoselectivity in the electrophilic alkylation
Tamura, Kenji,Yamazaki, Takashi,Kitazume, Tomoya,Kubota, Toshio
, p. 918 - 930 (2007/10/03)
The effect of fluoromethyl groups on the diastereoselectivity in the electrophilic alkylation is described. In particular, the electrophilic alkylation of enolates with a trifluoromethyl group was proceeded with highly diastereofacial selectivity based on the steric and/or electrostatic effect of substituent with strong electron withdrawing.
