The effects of C–S and C–Se bonds on torquoselectivity: stereoselective olefination of α-thio and α-selenoketones with ynolates
摘要:
Highly Z-selective olefination of acyclic alpha-thio and alpha-selenoketones with ynolates has been achieved, and the theoretical calculations of the transition states in the ring-opening of the intermediates, the beta-lactone enolates, revealed that the torquoselectivity was controlled by the secondary orbital interactions between the sigma orbital of the C-S bond or a lone pair orbital on the S and sigma* orbitals of the breaking C-O bond, and the sigma orbital of the breaking C-O bond or a lone pair orbital on the O on the ring and the sigma* orbitals of the C-S bond. The synthetic applications of the resulting olefins are also shown. (c) 2009 Elsevier Ltd. All rights reserved.
The effects of C–S and C–Se bonds on torquoselectivity: stereoselective olefination of α-thio and α-selenoketones with ynolates
作者:Takashi Yoshikawa、Seiji Mori、Mitsuru Shindo
DOI:10.1016/j.tet.2009.08.060
日期:2009.10
Highly Z-selective olefination of acyclic alpha-thio and alpha-selenoketones with ynolates has been achieved, and the theoretical calculations of the transition states in the ring-opening of the intermediates, the beta-lactone enolates, revealed that the torquoselectivity was controlled by the secondary orbital interactions between the sigma orbital of the C-S bond or a lone pair orbital on the S and sigma* orbitals of the breaking C-O bond, and the sigma orbital of the breaking C-O bond or a lone pair orbital on the O on the ring and the sigma* orbitals of the C-S bond. The synthetic applications of the resulting olefins are also shown. (c) 2009 Elsevier Ltd. All rights reserved.
Rhenium-Catalyzed Regio- and Stereoselective Synthesis of γ-Thio-α,β-unsaturated Ketones via Insertion of Terminal Alkynes into the C–S Bond
作者:Mitsumi Nishi、Yoichiro Kuninobu、Kazuhiko Takai
DOI:10.1021/ol302810u
日期:2012.12.7
α-thioketones and alkynes in the presence of a rhenium catalyst, [HRe(CO)4]n, gave γ-thio-α,β-unsaturatedketones in excellent yields. The alkynes were inserted into the carbon–sulfur bond of the α-thioketones, and isomerization of a double bond provided the products with high regio- and stereoselectivities. This reaction also proceeded in an intramolecular fashion.