A transition-metal-free multicomponent reaction towards constructing chiral 2<i>H</i>-1,4-benzoxazine scaffolds
作者:Lixiang Zhu、Xiaoyu Ren、Juan Du、Jia-Hong Wu、Jian-Ping Tan、Jixing Che、Jianke Pan、Tianli Wang
DOI:10.1039/d0gc02134b
日期:——
transition-metal-free multicomponent cascade reaction of readily available α-halogenated ketones, ortho-aminophenols, and aldehydes using a novel dipeptide-based phosphonium salt catalyst was developed for the efficient construction of various 2H-1,4-benzoxazine derivatives with excellent functional-group tolerance. The method represents an unprecedented approach for trapping active 1,5-bifunctional intermediates
本文中,开发了一种使用新型的基于二肽的phospho盐催化剂的易于获得的α-卤代酮,邻氨基酚和醛的无过渡金属的多组分级联反应,以有效地构建各种2 H -1,4-苯并恶嗪具有出色的官能团耐受性的衍生物。该方法代表了一种空前的方法,用于捕获具有α-卤代酮的活性1,5-双功能中间体,以访问具有两个非立体诱导中心且具有两个立体生成中心的生物学上重要的苯并恶嗪支架。
Neighboring phenolic group-activated <i>gem</i>-difluoroallylboration of imines for the catalyst-free synthesis of <i>gem</i>-difluorohomoallylamines
作者:Xing Yang、Feng Zhang、Yang Zhou、Yi-Yong Huang
DOI:10.1039/c8ob00541a
日期:——
We herein report an unprecedented addition reaction of pinacol gem-difluoroallylborates and imines enabled by a neighboring phenolic group in an N-protecting group under catalyst-free conditions, thus facilitating the construction of a wide range of racemic gem-difluorohomoallylamine derivatives. Based on the control experiments, a plausible transition state via the Zimmerman–Traxler model was proposed
An enantioselective bisvinylogous Mannich reaction of silyl ketene acetal with aldimines has been realized by using a chiral N,N′‐dioxide/Tm(OTf)3 complex as catalyst, providing an effective method to synthesize chiral ζ‐amino‐α,β,γ,δ‐unsaturated carbonyl compounds.
SDS/Ac<sub>2</sub>O/H<sub>2</sub>O: Surfactant‐Mediated Cleavage of Imines with Acetic Anhydride to Carbonyls and Acetanilides in Water
作者:Saikat Das Sharma、Pranjal Gogoi、Monalisa Boruah、Dilip Konwar
DOI:10.1080/00397910701459571
日期:2007.8
Surfactant ( SDS)-mediated cleavage of imines was achieved with acetic anhydride to the corresponding carbonyls ( aldehydes and ketones) and acetanilides in water at 25-30 degrees C with very good to excellent yields, thus contributing significantly to the green chemistry concept.
Mishra; Pandey, Indian Journal of Chemistry, Section A: Inorganic, Physical, Theoretical and Analytical, 2005, vol. 44, # 9, p. 1800 - 1805