Enzyme-promoted kinetic resolution of acetoxymethyl aryl sulfoxides
摘要:
A simple and efficient method of the synthesis of enantiomerically enriched, unknown acetoxymethyl aryl sulfoxides has been developed which is based on an enzyme-catalyzed hydrolysis of racemic substrates under the kinetic resolution conditions. The hydrolysis was performed not only in a buffer solution but also in diisopropyl ether in the absence of the external water added to give in some cases the products with ee up to 98%. The enantioselectivity of both procedures was dependent on the enzyme used and the aryl substituent, being lower for p-tolyl than for phenyl. A comparative asymmetric synthesis based on the oxidation of the corresponding sulfides using chiral oxidizing reagent turned out to be inferior to the method described. Absolute configuration of the newly synthesized compounds was ascribed on the basis of CD spectra. (C) 2015 Elsevier B.V. All rights reserved.
A highly selective, environmentally friendly, and scalable electrochemical protocol for the construction of α-acyloxy sulfides, through the synergistic effect of self-assembly-induced C(sp3)–H/O–H cross-coupling, is reported. It features exceptionally broad substrate scope, high regioselectivity, gram-scale synthesis, construction of complex molecules, and applicability to a variety of nucleophiles
Gold-Catalyzed, Iodine(III)-Mediated Direct Acyloxylation of the Unactivated C(sp<sup>3</sup>)-H Bonds of Methyl Sulfides
作者:Sheng-rong Guo、Pailla Santhosh Kumar、Yan-qin Yuan、Ming-hua Yang
DOI:10.1002/ejoc.201600632
日期:2016.9
An efficient reaction for the iodine(III)‐mediated acyloxylation of the unactivated C(sp3)–H bonds of methyl sulfides is reported. This strategy utilizes various hypervalent iodine reagents and involves an ionic pathway to deliver the desired products in excellent yields (DCE = 1,2‐dichloroethane).
Direct α-acyloxylation of organic sulfides with the hypervalent (diacyloxyiodo)benzene/tetra-n-butylammonium bromide (TBAB) reagent combination
作者:Dan Zhu、Denghu Chang、Shaoyan Gan、Lei Shi
DOI:10.1039/c6ra01799a
日期:——
A novel metal-free approach to directly synthesize α-acyloxy sulfides from readily available alkyl sulfides utilizing the hypervalent (diacyloxyiodo)benzene and TBAB reagent combination is reported. This transformation is characterized by its broad substrate scope in moderate to excellent yields, convenient operating conditions and outstanding functional group tolerance.