Highly enantioselective hydrogenation of new 2-functionalized quinoline derivatives
摘要:
The asymmetric hydrogenation of a new series of 2-functionalized quinolines has been developed in the presence of in situ generated catalysts obtained from [Ir(cod)Cl](2)/(R)-bisphosphine/I-2 combinations. The enantioselectivity levels were as high as 84-94% ee for the synthesis of 1,2,3,4-tetrahydroquinolines. (c) 2012 Elsevier Ltd. All rights reserved.
Water-removable ynamide coupling reagent for racemization-free syntheses of peptides, amides, and esters
作者:Tao Liu、Xue Zhang、Zejun Peng、Junfeng Zhao
DOI:10.1039/d1gc03498g
日期:——
A novel ynamide coupling reagent, the by-product of which can be removed by water, was reported. It promotes the direct coupling between carboxylic acids and amines, alcohols or thiols to provide amides, peptides, esters and thioesters, respectively. No detectable racemization was observed for all the coupling reactions of carboxylic acids containing an α-chiral center. Importantly, a simple acidic
作者:Radha Bam、Alexandros S. Pollatos、Austin J. Moser、Julian G. West
DOI:10.1039/d0sc05925k
日期:——
Herein we report a light-driven B12-based catalytic system that leverages this reactivity to convert alkyl electrophiles to olefins under incredibly mild conditions using only earth abundant elements. Further, this process exhibits a high level of regioselectivity, producing terminal olefins in moderate to excellent yield and exceptional selectivity. Finally, we are able to access a hitherto-unknown
脱卤化氢或消除卤化氢等价物仍然是安装生物学上重要的烯烃官能团的最简单方法之一。然而,这种转化通常需要苛刻的强碱性条件、稀有贵金属或两者兼而有之,限制了其在复杂分子合成中的适用性。Nature 在新型维生素 B 12依赖性光感受器 CarH 中寻求一种补充方法,其中钴-碳键的光解导致在温和的生理相关条件下选择性形成烯烃。在这里,我们报告了一个光驱动的 B 12基于催化系统,利用这种反应性在极其温和的条件下仅使用地球丰富的元素将烷基亲电子试剂转化为烯烃。此外,该工艺表现出高水平的区域选择性,以中等至优异的收率和出色的选择性生产末端烯烃。最后,我们能够使用两种钴催化剂串联使用迄今为止未知的转化,远程消除来生产具有优异区域选择性的亚末端烯烃。我们一起展示了维生素 B 12是开发温和烯烃形成反应的强大平台。
WATER-SOLUBLE YNAMIDE COUPLING REAGENT AND PREPARATION METHOD AND USE THEREOF
申请人:Xi'an Easy Peptide Biotechnology Co., Ltd.
公开号:US20220144793A1
公开(公告)日:2022-05-12
The present disclosure discloses a water-soluble ynamide coupling reagent and a method for using the water-soluble ynamide coupling reagent in the synthesis of amide, polypeptide, ester and thioester compound. The ynamide coupling reagent has the structure represented by the following formula (I):
and in the formula (I), R is one selected from the group consisting of methylsulfonyl, benzenesulfonyl, p-toluenesulfonyl, trifluoroacetyl and other electron withdrawing groups.
Synthesis of new chiral 2-functionalized-1,2,3,4-tetrahydroquinoline derivatives via asymmetric hydrogenation of substituted quinolines
作者:Anna M. Maj、Isabelle Suisse、Christophe Hardouin、Francine Agbossou-Niedercorn
DOI:10.1016/j.tet.2013.07.090
日期:2013.11
The asymmetrichydrogenation of a series of quinolines substituted by a variety of functionalized groups linked to the C2 carbon atom is providing access to optically enriched 2-functionalized 1,2,3,4-tetrahydroquinolines in the presence of in situ generated catalysts from [Ir(cod)Cl]2, a bisphosphine, and iodine. The enantioselectivity levels were as high as 96% ee.