Nickel-Catalyzed [4+2+2]-Type Annulation Reaction of Cyclobutanones with Diynes and Enynes
作者:Shinji Ashida、Masahiro Murakami
DOI:10.1246/bcsj.81.885
日期:2008.7.15
In the presence of a nickel(0) catalyst, cyclobutanones reacted with diynes to produce bicyclic eight-membered ring ketones. Cyclobutanones acted as a C4 unit in the formal [4+2+2]-type annulation reaction, which proceeded through a ring-expansion of a spirocyclic seven-membered oxanickelacycle to a nine-membered nickelacycle via β-carbon elimination. A similar annulation reaction was also examined with enynes.
Asymmetric catalysis: The rhodium‐catalyzed asymmetric [2+2+2] cyclization of 1,6‐enynes and aldehydes was achieved by using a cationicrhodium(I)/(R)‐binapcomplex as a catalyst (see scheme; cod=1,5‐cyclooctadiene). Coordination of the substrate heteroatom to the cationicrhodium plays an important role in this cyclization reaction.
Use of Rhodium N-Heterocyclic Carbene Complexes in Catalytic Cyclization and Hydrosilylation of 1,6-Enynes to 2-Methyl-1-silylmethylidene-2-cyclopentane
作者:Kang Hyun Park、So Yeon Kim、Seung Uk Son、Young Keun Chung
Enantioselective Cyclization/Hydrosilylation of 1,6-Enynes Catalyzed by a Cationic Rhodium Bis(phosphine) Complex
作者:Harinath Chakrapani、Cong Liu、Ross A. Widenhoefer
DOI:10.1021/ol027196n
日期:2003.1.1
[reaction: see text] Reaction of 4,4-dicarbomethoxy-1-octene-6-yne (1) with triethylsilane and a catalytic 1:1 mixture of [Rh(COD)(2)](+) SbF(6)(-) and (R)-BIPHEMP (5 mol %) at 70 degrees C for 90 min gave (Z)-1,1-dicarbomethoxy-3-(1-triethylsilyl)ethylidene-4-methylcyclopentane (2) in 81% isolated yield with 98% de and 92% ee.
One-Pot Cycloisomerization/Hetero-Diels–Alder Reaction of 1,6-Enynes with Aldehydes Catalyzed by Rhodium and a Brønsted Acid
作者:Mana Ishida、Ken Tanaka
DOI:10.1021/ol4005849
日期:2013.5.3
A rhodium and Bronsted acid catalyzed one-pot cycloisomerization/hetero-Diels-Alder reaction of 1,6-enynes with unactivated aldehydes was established under mild conditions. This one-pot catalytic protocol produced a wide variety of annulated dihydropyrans from readily available starting materials in a highly atom economical manner.