An efficientenantioselectiveinsertion of α-diazoesters and α-diazoketones into O–H bonds of carboxylic acids was realized by the use of Rh2(OAc)4 and a chiral guanidine. Optically active α-acyloxy carbonyl compounds were generated under mild reaction conditions in high yields (up to 99%) and good enantioselectivities (up to 97.5:2.5 er).
Catalyst-free, visible-light-promoted S–H insertion reaction between thiols and α-diazoesters
作者:Jingya Yang、Ganggang Wang、Shuwen Chen、Ben Ma、Hongyan Zhou、Menghui Song、Cai Liu、Congde Huo
DOI:10.1039/d0ob02006k
日期:——
A visible-light-promoted S–H insertion reaction betweenthiols and α-diazoesters was developed. The reaction proceeded smoothly at room temperature with a broad substrate scope, affording various thioethers in moderate to excellent yields. The catalyst- and additive-free nature, sustainable energy source and mild reaction conditions make this strategy more eco-friendly.
The development of an efficient method for the site‐selective substitution of unprotected phenols has long been considered as an attractive but challenging task. Herein, we describe a highly chemo‐ and ortho‐selective substitution reaction of phenols with α‐aryl α‐diazoacetates with commercially available (C6F5)3B as the catalyst. This reaction proceeds under simple and mild conditions with high efficiency
长期以来,人们一直认为开发一种有效的方法来对未保护的酚进行位点选择性取代是一项有吸引力的任务,但具有挑战性。本文中,我们描述了苯酚与α-芳基α-重氮乙酸酯的高度化学和邻位选择性取代反应,并以市售(C 6 F 5)3 B作为催化剂。该反应在简单温和的条件下以高效率进行,它具有广泛的底物范围,并且易于扩大规模。
Three-Component Ring-Opening Reactions of Cyclic Ethers, α-Diazo Esters, and Weak Nucleophiles under Metal-Free Conditions
作者:Lin Lu、Chuwei Chen、Huanfeng Jiang、Biaolin Yin
DOI:10.1021/acs.joc.8b02091
日期:2018.12.7
A protocol for three-component reactions of cyclic ethers, α-diazo esters, and weak nitrogen, oxygen, carbon, and sulfur nucleophiles (pKa = 2.2–14.8) to afford a variety of structurally complex α-oxyalkylated esters is reported. These reactions involve intermolecular activation of the cyclic ether (present in excess) by the α-diazo ester to form an oxonium ylide under metal-free conditions, followed
据报道,存在一种用于环醚,α-重氮酯与弱氮,氧,碳和硫亲核试剂(p K a = 2.2–14.8)的三组分反应的协议,该反应可提供多种结构复杂的α-氧基烷基化酯。这些反应包括在无金属条件下,α-重氮酯对环状醚(过量存在)进行分子间活化,形成叶立德叶立酮,然后由亲核试剂开环。