Potassium tris(triflyl)methide (KCTf<sub>3</sub>): a broadly applicable promoter for cationic metal catalysis
作者:Junbin Han、Zhichao Lu、Weibo Wang、Gerald B. Hammond、Bo Xu
DOI:10.1039/c5cc05306d
日期:——
KCTf3 enhanced the reaction rates and the chemical yields of a wide spectrum of cationic metalcatalyzed reactions in consistent and significant manner. These reactions include traditional Lewis acid catalysis and transition metal catalysis. KCTf3 is an easily handled neutral salt that is commercially available.
Enzymatickineticresolution of (±)-hydroxytetrahydropyrans has been achieved for the first time by means of lipase-mediated transesterification to afford optically active (2S,4R)-tetrahydropyranyl acetates and (2R,4S)-tetrahydropyranols in excellent yields with high enantioselectivity. Absolute configurations of the tetrahydropyranyl acetates were assigned as (S) by chemical correlation.
Scandium triflate catalyzed in situ Prins-type cyclization: formations of 4-tetrahydropyranols and ethers
作者:Wen-Chun Zhang、Ganapathy S. Viswanathan、Chao-Jun Li
DOI:10.1039/a808960d
日期:——
The reaction of aldehydes with homoallyl alcohols catalyzed by scandium triflate generates tetrahydropyran-4-ol and ethers in good yields.
在三酸钪催化下,醛与均烯丙基醇发生反应,生成四氢吡喃-4-醇和醚,产率很高。
ARYL SUBSTITUTED HETEROCYCLYL SULFONES
申请人:GRÜNENTHAL GMBH
公开号:US20150291573A1
公开(公告)日:2015-10-15
The invention relates to aryl substituted heterocyclyl sulfones as voltage gated calcium channel blockers, to pharmaceutical compositions containing these compounds and also to these compounds for use in the treatment and/or prophylaxis of pain and further diseases and/or disorders.
Efficient transesterification resolution of 2-(4-chlorophenyl)-4-hydroxytetrahydropyran with magnetically separable immobilized lipase
作者:Ping Xue、Zhen-Zhen Kang、Xiao-Yong Lai、Guan-Qun Qu、Yuan-Yuan Li
DOI:10.1016/j.cclet.2013.07.005
日期:2013.12
We report an efficient kinetic resolution of racemic 2-(4-chlorophenyl)-4-hydroxytetrahydro-pyran (CLP-4-HTHP) via Pseudomonas cepacia lipase (PSL)-catalyzed transesterification, where PSL is immobilized on a core-shell MnFe2O4@SiO2-(CH2)(3)-HH2 carrier and used as a magnetically separable catalyst. The as-synthesized PSL/MnFe2O4@SiO2-(CH2)(3)-NH2 catalyst exhibits enhanced catalytic activity for resolving racemic CLP-4-HTHP to the corresponding optically pure (2R,4S)-CLP-4-HTHP compared to the free PSL. The ee(s) for the former is 2.3 times larger than that for the latter under optimized conditions (99.4% and 44.1%, respectively), although the ee(p) for them are same (99.2%). Meanwhile, the PSL/MnFe2O4@SiO2-(CH2)(3)-NH2 catalyst possesses a high saturate magnetization of 59.7 emu/g and could be easily recovered by magnetic separation and reused. The catalytic activity in six recycling tests did not significantly decrease, suggesting its great potential for industrial applications. (C) 2013 Ping Xue. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.