Brønsted acid catalysed chemo- and <i>ortho</i>-selective aminomethylation of phenol
作者:Zhiqiong Tang、Dongdong Li、Yidi Yue、Dan Peng、Lu Liu
DOI:10.1039/d1ob00820j
日期:——
We have developed a Brønsted acidcatalysed highly ortho-selective functionalization of free phenols with readily available N,O-acetals under mild conditions, furnishing various corresponding aminomethylated phenol products in moderate to excellent yields. The salient features of this transformation include mild conditions, good substrate scope, excellent ortho-selectivity, high efficiency, and ease
A novel zinc-catalyzed reduction of tertiary amides was developed. This system shows remarkable chemoselectivity and substrate scope tolerating ester, ether, nitro, cyano, azo, and keto substituents.
The modified-Mannich reaction: Conversion of arylboronic acids and subsequent coupling with paraformaldehyde and amines toward the one-pot synthesis of Mannich bases and benzoxazines
作者:Juan Liu、Gaoqing Yuan
DOI:10.1016/j.tetlet.2017.02.081
日期:2017.4
A modified Mannichreaction has been developed for the synthesis of Mannichbases and benzoxazines via the oxidative hydroxylation of arylboronic acids and subsequent coupling with paraformaldehyde and amines in one pot. This modified Mannichreaction is easily carried out to afford the target products in good to excellent yields and tolerates a variety of functional groups.
Mild and Rapid Method for the Generation of <i>ortho</i>-(Naphtho)quinone Methide Intermediates
作者:Abdul kadar Shaikh、Alexander J. A. Cobb、George Varvounis
DOI:10.1021/ol203196n
日期:2012.1.20
A new mild method has been devised for generating o-(naphtho)quinonemethidesvia fluoride-induced desilylation of silyl derivatives of o-hydroxybenzyl(or 1-naphthylmethyl) nitrate. The reactive o-(naphtho)quinonemethideintermediates were trapped by C, O, N, and S nucleophiles and underwent “inverse electron-demand” hetero-Diels–Alder reaction with dienophiles to give stable adducts. The method has
Mild and Selective Et<sub>2</sub>Zn-Catalyzed Reduction of Tertiary Amides under Hydrosilylation Conditions
作者:Oleksandr O. Kovalenko、Alexey Volkov、Hans Adolfsson
DOI:10.1021/ol503430t
日期:2015.2.6
(Et2Zn) can be used as an efficient and chemoselective catalyst for the reduction of tertiary amides under mild reaction conditions employing cost-effective polymeric silane (PMHS) as the hydride source. Crucial for the catalytic activity was the addition of a substoichiometric amount of lithium chloride to the reaction mixture. A series of amides containingdifferent additional functionalgroups were reduced