Reductive elimination of alkylpalladium formate intermediates formed in enyne cyclizations
摘要:
Various enynes under the palladium catalysts,were successfully cyclized to the alkylpalladium intermediates, which then were reduced by the hydrogen in a formate ligand (C) 1999 Elsevier Science Ltd. All rights reserved.
A short synthesis of (±)-laurene: mechanistic reinvestigation in palladium-catalyzed cycloreductions of 1,6-enynes
作者:Chang Ho Oh、Je Wook Han、Joo Sung Kim、Sung Yong Um、Hyung Hoon Jung、Won Hyung Jang、Ho Shik Won
DOI:10.1016/s0040-4039(00)01484-2
日期:2000.10
Two palladium-catalyzed cycloreduction strategies have been applied for the synthesis of laurene. Palladium-catalyzedcyclizations of 1,6-enynes initially form the corresponding alkylpalladium intermediates. While triethylsilane could directly reduce the intermediates to lead to the corresponding cycloreduced products, the intermediates in the presence of even excess formic acid underwent β-elimination
Reductive elimination of alkylpalladium formate intermediates formed in enyne cyclizations
作者:Chang Ho Oh、Hyung Hoon Jung
DOI:10.1016/s0040-4039(98)02704-x
日期:1999.2
Various enynes under the palladium catalysts,were successfully cyclized to the alkylpalladium intermediates, which then were reduced by the hydrogen in a formate ligand (C) 1999 Elsevier Science Ltd. All rights reserved.
Regio- and stereoselectivity in palladium-catalyzed cycloreductions of 1,6-enynes in the presence of formic acid or triethylsilane
作者:Chang Ho Oh、Hyung Hoon Jung、Hye Rhyan Sung、Jung Duk Kim
DOI:10.1016/s0040-4020(01)00008-4
日期:2001.2
Palladium catalyzed 1,6-enyne cycloreductions in the presence of 1.2 equiv. of formic acid (method A) would involve cycloalkylpalladium formates which proceed via two consecutive steps: beta -elimination of alkylpalladium intermediates and then reduction at the less hindered olefins regio- and stereoselectivity. Triethylsilane, however, directly reduced the alkylpalladium intermediates to give the corresponding cycloreduced products (method B). (C) 2001 Elsevier Science Ltd. All rights reserved.