手性铜( II )络合物催化丙二酸酯对β,γ-不饱和-α-酮酯的对映选择性迈克尔加成反应,实现了高产率(高达96%)和高ee(高达92%) 。手性配体同时利用了联萘基和脯氨酸部分,并且可以容忍具有不同电子和空间特征的取代基。反应可以在温和的条件下进行,并且可以在不损失产率和对映选择性的情况下实现克级反应。
A new ring for your indole: An unprecedented copper‐catalyzed enantioselectiveFriedel–Craftsalkylation/N‐hemiacetalization cascade reaction with indoles and β,γ‐unsaturated α‐ketoesters is reported. This mild strategy provides new access to various synthetically and biologically important 2,3‐dihydro‐1H‐pyrrolo[1,2‐a]indoles in a highlyenantioselective manner.
吲哚的新环:据报道,铜与吲哚和β,γ-不饱和α-酮酸酯发生了前所未有的铜催化对映选择性Friedel-Crafts烷基化/ N-半缩醛化级联反应。这种温和的策略以高度对映选择性的方式为各种合成和生物学上重要的2,3-二氢-1 H-吡咯并[1,2- a ]吲哚提供了新途径。
Neighboring Thioether Participation in Bioinspired Radical Oxidative C(sp<sup>3</sup>)–H α-Oxyamination of Pyruvate Derivatives
A bioinspired radical oxidative α-oxyamination of pyruvate with an oxoammonium salt through multiple-site concerted proton–electron transfer process has been developed, which was facilitated by anchoring the mercapoto chains as a “hopping” site at the γ-position of α-keto esters.
Catalytic Generation of Donor-Acceptor Cyclopropanes under <i>N</i>
-Heterocyclic Carbene Activation and their Stereoselective Reaction with Alkylideneoxindoles
作者:Liher Prieto、Eduardo Sánchez-Díez、Uxue Uria、Efraím Reyes、Luisa Carrillo、Jose L. Vicario
DOI:10.1002/adsc.201700198
日期:2017.5.17
Formylcyclopropanes undergo activation in the presence of an N‐heterocyclic carbene catalyst generating a donor‐acceptorcyclopropane intermediate with the ability to undergo ring‐opening followed by formal [4+2] cycloaddition with alkylideneoxindoles. This enables the direct enantio‐ and diastereoselective synthesis of tetrahydropyrano[2,3‐b]indoles through the use of a chiral NHC catalyst.
甲酰基环丙烷在N杂环卡宾催化剂的存在下发生活化,生成供体-受体环丙烷中间体,该中间体具有开环能力,然后与亚烷基亚氧吲哚进行正式的[4 + 2]环加成反应。这样可以通过使用手性NHC催化剂直接对映和非对映选择性合成四氢吡喃并[2,3- b ]吲哚。
Enantioselective phospha-Michael addition of diarylphosphines to β,γ-unsaturated α-ketoesters and amides
作者:Renta Jonathan Chew、Kai Yuan Teo、Yinhua Huang、Bin-Bin Li、Yongxin Li、Sumod A. Pullarkat、Pak-Hing Leung
DOI:10.1039/c4cc01610f
日期:——
A chiral palladacycle catalyzed hydrophosphination of β,γ-unsaturated α-ketoesters and amides has been developed; with up to 99% yield and 90% ee.
Highly Enantioselective Nickel-Catalyzed Oxa-[3+3]-annulation of Phenols with Benzylidene Pyruvates for Chiral Chromans
作者:Hai Ren、Xiang-Yang Song、Sunewang R. Wang、Lijia Wang、Yong Tang
DOI:10.1021/acs.orglett.8b01442
日期:2018.7.6
Nickel-catalyzed asymmetric annulation of oxygenated phenols and previously challenging 3-aminophenols with β,γ-unsaturated α-ketoesters is described, leading to rapid access to a variety of oxygenated and 7-aminated chromans in excellent yields with excellent diastereoselectivities and enantioselectivities under mild conditions. This method was readily scaled-up to gram scale and applied for a concise