Asymmetric Michael Addition of <i>N</i>-<i>tert</i>-Butanesulfinyl Imidate with α,β-Unsaturated Diesters: Scope and Application to the Synthesis of Indanone Derivatives
作者:Jinfang Wang、Yu Zhou、Lei Zhang、Zeng Li、Xianjie Chen、Hong Liu
DOI:10.1021/ol400277h
日期:2013.4.5
An additive-free and highly diastereoselective Michaeladdition reaction of an N-tert-butanesulfinyl imidate to α,β-unsaturated diesters has been developed using LDA as a base with good to excellent yields. The utility of this chemistry is further demonstrated by the asymmetric synthesis of 3-substituted indanone derivatives 8a, 8d, 8e, and 8i with high enantiomeric excess, which are potential building
Catalytic enantioselective conjugate additions with easily accessible alkenylboronic acid pinacol esters as nucleophiles promoted by chiral copper complexes of N-heterocyclic carbenes are presented. These processes constitute an unprecedented instance of conjugate additions of a variety of functionalized alkenyl groups and afford desired products that are otherwise difficult to access in up to 98%
[3+3] Annulation via Ring Opening/Cyclization of Donor-Acceptor Cyclopropanes with (Un)symmetrical Ureas: A Quick Access to Highly Functionalized Tetrahydropyrimidinones
straight‐forward access to pharmacologically privileged tetrahydropyrimidinones exploiting readily available Donor–Acceptorcyclopropanes (DACs) is reported. This methodology involves the Lewis acid catalyzed synthesis of uriedo‐malonates from (un)symmetrical and unsymmetrical ureas and DACs followed by I2‐base mediated cyclization to form their corresponding tetrahydropyrimidinones in moderate to excellent
Catalytic Asymmetric Conjugate Addition of a Borylalkyl Copper Complex for Chiral Organoboronate Synthesis
作者:Won Jun Jang、Jaesook Yun
DOI:10.1002/anie.201909712
日期:2019.12.9
We report the catalytic enantioselectiveconjugateaddition of a borylalkyl copper nucleophile generated in situ from a 1,1-diborylmethane derivative to α,β-unsaturated diesters. In the presence of a chiral N-heterocyclic carbene (NHC)-copper catalyst, this method facilitated the enantioselective incorporation of a CH2 Bpin moiety at the β-position of the diesters to yield β-chiral alkyl boronates
Asymmetric Conjugate Addition of Chiral Secondary Borylalkyl Copper Species
作者:Won Jun Jang、Jeongkyu Woo、Jaesook Yun
DOI:10.1002/anie.202014425
日期:2021.2.23
We report the diastereo‐ and enantioselective conjugateaddition of chiral secondary borylalkyl copper species derived from borylalkenes in situ to α,β‐unsaturated diesters. In the presence of a chiral bisphosphine‐ligated CuH catalyst, the conjugateaddition provides a direct access to enantioenriched alkylboron compounds containing two contiguous carbon stereogenic centers in good yield with high