Manganese-Catalyzed Borylation of Unactivated Alkyl Chlorides
作者:Thomas C. Atack、Silas P. Cook
DOI:10.1021/jacs.6b03157
日期:2016.5.18
of (bis)pinacolatodiboron with a wide range of alkyl halides, demonstrating the first manganese-catalyzed coupling with alkyl electrophiles. This method allows access to primary, secondary, and tertiary boronic esters from the parent chlorides, which were previously inaccessible as coupling partners. The reaction proceeds in high yield with as little as 1000 ppm catalyst loading, while 5 mol % can
Bulky Cyclometalated Ruthenium Nitrates for Challenging
<i>Z</i>
‐Selective Metathesis: Efficient One‐Step Access to α‐Oxygenated
<i>Z</i>
‐Olefins from Acrylates and Allyl Alcohols
作者:Yan Xu、Quan Gan、Adrian E. Samkian、Jeong Hoon Ko、Robert H. Grubbs
DOI:10.1002/anie.202113089
日期:2022.1.21
metathesis is the lack of a widely applicable method that converts feedstock allyl alcohols and acrylates to valuable α-oxygenated Z-olefins. Here, enabled by bulky cyclometalated Ru-nitrate catalysts whose syntheses were newly unlocked, Z-selective metathesis between terminal olefins could now be used to access Z-allyl alcohols, Z-alkenyl esters, and Z-alkenyl acids in high yields and >20 : 1 Z : E selectivity
烯烃复分解的一个持久挑战是缺乏将原料烯丙醇和丙烯酸酯转化为有价值的α-氧化Z-烯烃的广泛适用的方法。在这里,通过新解锁合成的庞大的环金属化硝酸钌催化剂,末端烯烃之间的Z选择性复分解现在可以用于以高产率和 >20 : 1 Z : E选择性。
作者:Yan Xu、Jonathan J. Wong、Adrian E. Samkian、Jeong Hoon Ko、Shuming Chen、K. N. Houk、Robert H. Grubbs
DOI:10.1021/jacs.0c11334
日期:2020.12.16
cyclometalated ruthenium catalysts with bulky N-heterocycliccarbene (NHC) ligands. Superior reactivity and stereoselectivity are realized for the first time in this challenging transformation, allowing streamlined access to an important class of cis-Michael acceptors from readily available feedstocks. The kinetic preference for cross-metathesis is enabled by a pivalate anionic ligand, and the origin
通过使用具有庞大 N-杂环卡宾 (NHC) 配体的新型环金属化钌催化剂,开发了丙烯酰胺和普通末端烯烃之间的高效 Z 选择性交叉复分解。在这一具有挑战性的转化中首次实现了卓越的反应性和立体选择性,允许从现成的原料中简化获得一类重要的顺式迈克尔受体。交叉复分解的动力学偏好是由新戊酸盐阴离子配体实现的,这种效应的起源通过密度泛函理论计算得到阐明。
Nickel-Catalyzed Umpolung Arylation of Ambiphilic α-Bromoalkyl Boronic Esters
作者:Shang-Zheng Sun、Ruben Martin
DOI:10.1002/anie.201712428
日期:2018.3.26
A nickel‐catalyzed reductive arylation of ambiphilic α‐bromoalkyl boronic esters with aryl halides is described. This platform provides an unrecognized opportunity to promote the catalytic umpolung reactivity of ambiphilic reagents with aryl halides, thus unlocking a new cross‐coupling strategy that complements existing methods for the preparation of densely functionalized alkyl‐substituted organometallic
Convergent Catalytic Asymmetric Synthesis of Esters of Chiral Dialkyl Carbinols
作者:Ze-Peng Yang、Gregory C. Fu
DOI:10.1021/jacs.0c01324
日期:2020.3.25
Because chiral dialkyl carbinols, as well as their derived esters, are significant as intermediates and end points in fields such as organic, pharmaceutical, and biological chemistry, the development of efficient approaches to their asymmetric synthesis is an important endeavor. In this report, we describe a method for the direct catalytic enantioselective synthesis of such esters, beginning with an