Cooperative Activation of Alkyne and Thioamide Functionalities; Direct Catalytic Asymmetric Conjugate Addition of Terminal Alkynes to α,β-Unsaturated Thioamides
作者:Ryo Yazaki、Naoya Kumagai、Masakatsu Shibasaki
DOI:10.1002/asia.201100050
日期:2011.7.4
revealed that the intermediate copper‐thioamide enolate functioned as a Brønsted base to generate copper alkynylide from the terminal alkyne, thus driving the catalytic cycle through an efficient proton transfer between substrates. These findings led to the identification of a more convenient catalyst using potassium hexamethyldisilazane (KHMDS) as the Brønsted base, which was particularly effective for
Catalyticasymmetricconjugateaddition of nitroalkanes to α,β-unsaturated thioamides is promoted by a mesitylcopper/(R)-DTBM-Segphos precatalyst, affording γ-nitrothioamides in moderate to high syn-selectivity and excellent enantioselectivity. The intermediate Cu-thioamide enolate functions as a soft Lewis acid/hard Brønsted base cooperative catalyst to drive the catalytic cycle efficiently under
Soft Lewis acid/Brønsted base cooperative catalysts have enabled directcatalyticasymmetricvinylogous conjugate addition of α,β‐ and β,γ‐unsaturated butyrolactones to α,β‐unsaturated thioamides with perfect atom economy. When using α‐angelica lactone and its derivatives as pronucleophiles, as little as 0.5 mol % catalyst loading was sufficient to complete the reaction necessary to construct consecutive
Enantioselective Synthesis of a GPR40 Agonist AMG 837 via Catalytic Asymmetric Conjugate Addition of Terminal Alkyne to α,β-Unsaturated Thioamide
作者:Ryo Yazaki、Naoya Kumagai、Masakatsu Shibasaki
DOI:10.1021/ol102998w
日期:2011.3.4
route to a potent GPR40 agonist AMG 837 is described. The crucial catalyticasymmetricconjugateaddition of terminal alkyne was promoted by a soft Lewis acid/hard Brønsted base cooperative catalyst, allowing efficient construction of the requisite stereogenic center. The thioamide functional group is key to both activation in asymmetric alkynylation and facile transformation into carboxylic acid.
Copper(I)‐Catalyzed Conjugate Addition/Enantioselective Protonation with Selenols and α‐Substituted α,β‐Unsaturated Thioamides
作者:Hu Tian、Hong‐Ming Zhang、Liang Yin
DOI:10.1002/anie.202301422
日期:2023.6.12
A copper(I)-catalyzed conjugate addition/enantioselective protonation with selenols and α-substituted α,β-unsaturated thioamides is disclosed, which affords a series of chiral selenides in high to excellent enantioselectivity.