Chemo- and Regioselective Cyclohydrocarbonylation of α-Keto Alkynes Catalyzed by a Zwitterionic Rhodium Complex and Triphenyl Phosphite
摘要:
alpha-Keto alkynes react with CO and H-2 in the presence of catalytic quantities of the zwitterionic rhodium complex (eta(6)-C6H5BPh3)Rh--(+)(1,5-COD) and triphenyl phosphite affording either the 2-, 2(3H)-, or 2(5H)-furanones in 61-93% yields. The cyclohydrocarbonylation is readily accomplished using substrates containing alkyl, aryl, vinyl, and alkoxy groups at the acetylenic terminal, as well as a variety of primary, secondary, and tertiary alkyl, aryl, and heteroaryl groups connected to the ketone functionality. Structural and electronic properties present in the starting materials mediate the chemo- and regioselectivity of the reaction.
Photocycloaddition of Enynones (4-Acylbut-1-en-3-ynes) to Alkenes
作者:Inga Inhülsen、Paul Margaretha
DOI:10.1021/ol902827s
日期:2010.2.19
The title compounds undergo regio- and diastereoselective [2+2]-cycloaddition at the olefinic C-C bond on irradiation (350 nm) in the presence of either methacrylonitrile or 2,3-dimethylbuta-1,3-diene, affording hitherto unknown 1-cyclobutylalk-1-yn-3-ones or 1-bicyclo[4.2.0]octylalk-1-yn-3-ones, respectively.
Preparation of δ-Chloro-α-allenyl Ketones by Acylation of 3-Buten-1-ynes
AlC(l)3-mediated acylation of 3-buten-1-yne derivatives with acyl chlorides yields a mixture of 5-chloro-2,3-pentadienones and 3-chloro-2,4-pentadienones. The proportion of allenyl ketones vs conjugated dienic ketones depends on the substitution pattern of the starting enyne, Acylation of 5-acetoxy-3-buten-1-ynes leads to the corresponding allenyl ketones (6-acetoxy-5-chloro-2,3-pentadienones).
Chemo- and Regioselective Cyclohydrocarbonylation of α-Keto Alkynes Catalyzed by a Zwitterionic Rhodium Complex and Triphenyl Phosphite
作者:Bernard G. Van den Hoven、Bassam El Ali、Howard Alper
DOI:10.1021/jo000230w
日期:2000.6.1
alpha-Keto alkynes react with CO and H-2 in the presence of catalytic quantities of the zwitterionic rhodium complex (eta(6)-C6H5BPh3)Rh--(+)(1,5-COD) and triphenyl phosphite affording either the 2-, 2(3H)-, or 2(5H)-furanones in 61-93% yields. The cyclohydrocarbonylation is readily accomplished using substrates containing alkyl, aryl, vinyl, and alkoxy groups at the acetylenic terminal, as well as a variety of primary, secondary, and tertiary alkyl, aryl, and heteroaryl groups connected to the ketone functionality. Structural and electronic properties present in the starting materials mediate the chemo- and regioselectivity of the reaction.
BADANYAN SH. O.; MINASYAN T. T., AJKAKAN XIMIAKAN AMSAGIR, ARM. XIM. ZH., 1978, 31, HO 6 452-453