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
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
Enantioselective Reactions of 2‐Sulfonylalkyl Phenols with Allenic Esters: Dynamic Kinetic Resolution and [4+2] Cycloaddition Involving
<i>ortho</i>
‐Quinone Methide Intermediates
作者:Ping Chen、Kai Wang、Wengang Guo、Xianghui Liu、Yan Liu、Can Li
DOI:10.1002/anie.201700250
日期:2017.3.20
report herein a dynamic kinetic resolution (DKR) involving ortho‐quinone methide (o‐QM) intermediates. In the presence of Et3N and the cinchonine‐derived nucleophilic catalyst D, the DKR of 2‐sulfonylalkyl phenols with allenic esters afforded chiral benzylic sulfones in 57–79 % yield with good to excellent enantioselectivity (85–95 % ee). Furthermore, with 2‐(tosylmethyl)sesamols or 2‐(tosylmethyl)naphthols
ammonium ylides and o-quinone methides for the synthesis of a variety of 2,3-dihydrobenzofurans has been developed. The key factors controlling the reactivity and stereoselectivity were systematically investigated by experimental and computational means and the energy profiles obtained provide a deeper insight into the mechanistic details of this reaction.