The Iridium-catalyzed enantioselective couplingreaction of vinyl azides and allylic electrophiles is presented and provides access to β-chiral carbonyl derivatives. Vinyl azide are used as acetamide enolate or acetonitrile carbanion surrogates, leading to γ,δ-unsaturated β-substituted amides as well as nitriles with excellent enantiomeric excess. The products are readily transformed into chiral N-containing
Iridium-Catalyzed Enantioselective Synthesis of α-Chiral Bicyclo[1.1.1]pentanes by 1,3-Difunctionalization of [1.1.1]Propellane
作者:Songjie Yu、Changcheng Jing、Adam Noble、Varinder K. Aggarwal
DOI:10.1021/acs.orglett.0c02017
日期:2020.7.17
3-difunctionalization of [1.1.1]propellane with Grignard reagents and allyl carbonates using iridium catalysis. This mild protocol proceeds via initial organometallic addition to [1.1.1]propellane followed by asymmetric allylic substitution, providing the products with high enantioselectivities over a broad range of substrates. Further derivatization of the products demonstrates the applicability of this method
Iridium-Catalyzed Enantioselective Allylic Substitution with Aqueous Solutions of Nucleophiles
作者:Tobias Sandmeier、F. Wieland Goetzke、Simon Krautwald、Erick M. Carreira
DOI:10.1021/jacs.9b05830
日期:2019.8.7
The iridium-catalyzed asymmetric allylic substitution under biphasic conditions is reported. This approach allows the use of various unstable and/or volatile nucleophiles including hydrazines, methyl-amine, t-butyl hydroperoxide, N-hydroxylamine, α-chloroacetaldehyde and glutaraldehyde. This transformation pro-vides rapid access to a broad range of products from simple starting materials in good yields
报道了双相条件下铱催化的不对称烯丙基取代。这种方法允许使用各种不稳定和/或挥发性亲核试剂,包括肼、甲胺、叔丁基过氧化氢、N-羟胺、α-氯乙醛和戊二醛。这种转变提供了从简单的起始材料以良好的产率和高达 > 99% ee 和 20:1 dr 快速获得广泛产品的途径。此外,这些产品可以有效地加工成多种环状和非环状化合物,最多可带有四个立体中心。
Cobalt-Catalyzed Diastereo- and Enantioselective Reductive Allyl Additions to Aldehydes with Allylic Alcohol Derivatives via Allyl Radical Intermediates
enantioenriched homoallylic alcohols with a remarkably broad scope of allyl groups that can be introduced. Mechanistic studies indicated that allyl radical intermediates were involved in this process. These new discoveries establish a new strategy for development of enantioselective transformations through capture of radicals by chiral Co complexes, pushing forward the frontier of Co complexes for enantioselective
Generation and Application of (Diborylmethyl)zinc(II) Species: Access to Enantioenriched <i>gem</i>
-Diborylalkanes by an Asymmetric Allylic Substitution
作者:Yeosan Lee、Jinyoung Park、Seung Hwan Cho
DOI:10.1002/anie.201805476
日期:2018.9.24
We report the successful generation of (diborylmethyl)zinc(II) species by transmetallation beteween isolable (diborylmethyl)lithium and zinc(II) halide (X=Br, Cl) and their application in the synthesis of enantioenriched gem‐diborylalkanes bearing a stereogenic center at the β‐position of the diboryl groups by an asymmetric allylic substitution reaction. The reaction has a broad substrate scope, and