An Iterative Catalytic Route to Enantiopure Deoxypropionate Subunits: Asymmetric Conjugate Addition of Grignard Reagents to α,β-Unsaturated Thioesters
作者:Renaud Des Mazery、Maddalena Pullez、Fernando López、Syuzanna R. Harutyunyan、Adriaan J. Minnaard、Ben L. Feringa
DOI:10.1021/ja053020f
日期:2005.7.1
A highly enantioselective (up to 96% ee) conjugate addition of Grignard reagents, in particular, MeMgBr, to alpha,beta-unsaturated thioesters is provided as well as its application to a diastereo- and enantioselective iterative route to syn- and anti-1,3-dimethyl arrays and deoxypropionate subunits. The versatility of the method is illustrated in the synthesis of (-)-lardolure, a multimethyl-branched
Highly Versatile Enantioselective Conjugate Addition of Grignard Reagents to α,β-Unsaturated Thioesters
作者:Beatriz Maciá Ruiz、Koen Geurts、M. Ángeles Fernández-Ibáñez、Bjorn ter Horst、Adriaan J. Minnaard、Ben L. Feringa
DOI:10.1021/ol702425a
日期:2007.11.1
for the asymmetric copper-catalyzed conjugateaddition of Grignard reagents to alpha,beta-unsaturated thioesters. MeMgBr adds to aromatic alpha,beta-unsaturated thioesters with excellent enantioselectivities and moderate to good yields using Josiphos/CuBr and Tol-BINAP/CuI complexes. The use of bulky Grignard reagents leads to unprecedented enantioselectivities in the 1,4-addition to a broad range
A new method for synthesizing α,β-acetylenic ketones by palladium-mediated coupling of thiol esters with 1-alkynes is described. The reaction could be applied to coupling of thiol esters bearing various functional groups,such as aromatic bromides, and ketones, with functionalized terminal acetylenes.
A variety of ketones have been prepared by a palladium-catalyzed reaction of ethanethiol esters with organozinc reagents. Various functional groups, including esters, ketones, aromatic halides and aldehydes, tolerate the reaction conditions. The reaction can also be applied to the synthesis of α-amino ketones using the corresponding L-α-amino thiol esters without racemization.
Asymmetric conjugate addition of alkylzirconium reagents to α,β-unsaturated thioesters: access to fragrances and acyclic stereochemical arrays
作者:Zhenbo Gao、Stephen P. Fletcher
DOI:10.1039/c7cc05433e
日期:——
Copper-catalyzed asymmetric conjugateaddition of alkylzirconium species to α,β-unsaturated thioesters is reported. A variety of functioanlized alkyl nucleophiles were introduced with yields around 70% and ee’s over 92%. The method was applied to the straightforward syntheses of the commercially important fragrances phenoxanol (both enantiomers 97% ee), and hydroxycitronellal (98% ee). The 1,4-addition