Efficient Generation and Increased Reactivity in Cationic Gold via Brønsted Acid or Lewis Acid Assisted Activation of an Imidogold Precatalyst
作者:Junbin Han、Naoto Shimizu、Zhichao Lu、Hideki Amii、Gerald B. Hammond、Bo Xu
DOI:10.1021/ol501443m
日期:2014.7.3
Brønsted or Lewis acid assisted activation of an imidogold precatalyst (L-Au-Pht, Pht = phthalimide) offers a superior way to generate cationic gold compared with the commonly used silver-based system. It is also broadly applicable for most common gold-catalyzed reactions. For reactions that require milder conditions, milder acids can be used for optimized efficiency.
Carboxylative cyclization of substituted propenyl ketones using CO<sub>2</sub>: transition-metal-free synthesis of α-pyrones
作者:Wen-Zhen Zhang、Ming-Wang Yang、Xiao-Bing Lu
DOI:10.1039/c6gc01346e
日期:——
Carbon dioxide is a green carboxylative reagent with regard to its non-toxic and renewable property. Described herein is a carboxylative cyclization of substituted 1-propenyl ketones via [gamma]-carboxylation using CO2, which...
A Highly Efficient and Broadly Applicable Cationic Gold Catalyst
作者:Deepika Malhotra、Mark S. Mashuta、Gerald B. Hammond、Bo Xu
DOI:10.1002/anie.201310239
日期:2014.4.22
Goldcatalysts capable of promoting reactions at low‐level loadings under mild conditions are the exception rather than the norm. We examined reactions where the regeneration of cationicgoldcatalyst (e.g., protodeauration) was the turnover limiting stage. By manipulating electron density on the substituents around phosphorus and introducing steric handles we designed a phosphine ligand that contains
Enhanced Reactivity in Homogeneous Gold Catalysis through Hydrogen Bonding
作者:Weibo Wang、Manish Kumar、Gerald B. Hammond、Bo Xu
DOI:10.1021/ol403584e
日期:2014.1.17
those instances where protodeauration is the rate-determining step. The efficiency of additives capable of hydrogen-bonding-assisted protodeauration correlated with their standing in a scale of hydrogenbonding basicity (measured by pKBHX). All additives used in the study are commercially available.
在原型脱氢是决定速率的步骤的情况下,良好的氢键受体添加剂可提高金催化反应的效率。能够进行氢键辅助原型脱氢的添加剂的效率与其在氢键碱度(以p K BHX衡量)中的地位相关。研究中使用的所有添加剂都是可商购的。