Direct amination of 2-(1-tosylalkyl)phenols with aqueous ammonia: a metal-free synthesis of primary amines
摘要:
A metal-free and concise method for the selective synthesis of primary amines directly from 2-(1-tosylalkyl)phenols with aqueous ammonia under mild conditions has been developed. In addition, primary amine could be conveniently converted to benzoxazinone in good yield. (C) 2015 Elsevier Ltd. All rights reserved.
Formal Asymmetric Catalytic Thiolation with a Bifunctional Catalyst at a Water-Oil Interface: Synthesis of Benzyl Thiols
作者:Wengang Guo、Bo Wu、Xin Zhou、Ping Chen、Xu Wang、Yong-Gui Zhou、Yan Liu、Can Li
DOI:10.1002/anie.201409894
日期:2015.4.7
The transformation proceeds with high yield (up to 99 %) and stereoselectivity (up to 97:3 e.r.) using water as solvent under mild conditions. The catalyst system provides a new strategy for the synthesis of optically active benzyl mercaptans. Control experiments suggested that o‐QMs are generated by the tertiary amine moiety of the squaramide organocatalyst and that the water–oil biphase is crucial
Enantioselective γ-Addition-Driven Cascade of β,γ-Unsaturated Ketones by Ion-Pair Catalysis: Access to Chiral 1,3-Dioxolochroman Scaffolds
作者:Xuemei Wang、Liang Zhou、Hongkui Zhang、Xiaoyu Ren、Guowei Gao、Tianli Wang
DOI:10.1021/acs.orglett.1c03567
日期:2022.1.14
A highlyenantioselective γ-addition-driven cascade of β,γ-unsaturated carbonyl compounds by bifunctional ion-pair catalysis has been developed. With this protocol, a range of functionalized chiral 1,3-dioxolochroman derivatives were prepared in high yields with superior stereoselectivities (>99% ee and >20:1 dr). The utility of this method was demonstrated by one-pot synthesis, scaled-up preparation
developed. A variety of eight-membered cyclic ethers with two contiguous tertiary stereocenters were obtained in high yields with excellent stereoselectivities. This reaction not only provides a new strategy for constructing enantioenriched eight-membered cyclic ethers but also demonstrates the practicability of ynones as C4-syntons for the synthesis of chiral medium-membered rings.
Organocatalytic stereoselective conjugate addition of 3-substituted oxindoles with in situ generated ortho-quinone methides
作者:Weihong Liang、Wenhao Yin、Tingzhong Wang、Fayang G. Qiu、Junling Zhao
DOI:10.1016/j.tetlet.2018.03.069
日期:2018.5
A novel method for the stereoselectiveconjugateaddition of 3-substituted oxindoles to in situ generated o-QMs was described. This process was catalyzed efficiently by a cinchonidine-derived squaramide catalyst in oil-water phase, furnishing the corresponding 3,3-disubsituted oxindole derivatives in moderate to high yields (up to 98%) with high stereoselectivities (up to 95% ee, 15.4:1 dr). The utility
Straightforward Synthesis of Bifunctional Phosphorus Phenols via Phosphination of In Situ Generated o-Quinone Methides
作者:Zhangpei Chen、Qinglong Shi、Gongshu Wang、Siwen Chen、Jianshe Hu
DOI:10.3390/molecules23061240
日期:——
An efficient and practical approach towards bifunctional phosphorus phenols has been developed through a reaction of diphenylphosphine oxide and the o-quinone methides in situ generatedfrom 2-tosylalkyl phenols under basic conditions. This protocol features simple experimental procedures under mild conditions and is easily scaled up. With this method, a variety of diarylmethyl phosphine oxides can