Enantioselective Intermolecular [2 + 2 + 2] Cycloadditions of Ene–Allenes with Allenoates
摘要:
An enantioselective [2 + 2 + 2] cycloaddition of ene-allenes with allenoates is described, which transforms simple pi-components into stereochemically complex carbocycles in a single step. The rhodium(I)-catalyzed cycloaddition proceeds with good levels of enantioselectivity, and with high levels of regio-, chemo-, and diastereoselectivity. Our results are consistent with a mechanism involving an enantioselective intermolecular allene-allene oxidative coupling.
Rhodium(I)-Catalyzed Ene-Allene-Allene [2+2+2] Cycloadditions: Stereoselective Synthesis of Complex trans-Fused Carbocycles
作者:Andrew T. Brusoe、Erik J. Alexanian
DOI:10.1002/anie.201100272
日期:2011.7.11
A complex situation: The title reaction was utilized for the construction of a variety of trans‐fused hydrindanes and decalins in a highly convergent manner (see scheme; binap=2,2′‐bis(diphenylphosphanyl)‐1,1′‐binaphthyl, Tf=trifluoromethanesulfonate), with three σ bonds, two rings, and up to four contiguous stereocenters generated in a regio‐ and stereoselective fashion.
Enantioselective Intermolecular [2 + 2 + 2] Cycloadditions of Ene–Allenes with Allenoates
作者:Andrew T. Brusoe、Rahul V. Edwankar、Erik J. Alexanian
DOI:10.1021/ol303024q
日期:2012.12.7
An enantioselective [2 + 2 + 2] cycloaddition of ene-allenes with allenoates is described, which transforms simple pi-components into stereochemically complex carbocycles in a single step. The rhodium(I)-catalyzed cycloaddition proceeds with good levels of enantioselectivity, and with high levels of regio-, chemo-, and diastereoselectivity. Our results are consistent with a mechanism involving an enantioselective intermolecular allene-allene oxidative coupling.