A Fe2(CO)9-mediated [5+1] cycloaddition of vinylcyclopropanes (VCPs) and CO to α, β-cyclohexenones has been developed. The reaction can tolerate aryl and aliphatic groups at the α-position of VCPs, while VCP substrates with vinyl or alkynyl substitutions are not suitable ones. In addition, this reaction can also be used to synthesize bicyclic rings if an aryl group is attached to the vinyl moiety of
Tuning of Vinylborane Dienophilicity. Optimization of Reactivity, Regioselectivity, endo-Stereoselectivity, and Reagent Stability
作者:Daniel A. Singleton、Jose P. Martinez、José V. Watson、Grace M. Ndip
DOI:10.1016/s0040-4020(01)90174-7
日期:1992.7
Diels-Alder reactions are compared. Vinyl-3,6-dimethylborepane was the most stable simple vinylborane examined, and appears to be indefinitely stable at 25°C. Surprisingly, trivinylborane is the most reactive, and reacts about 18 times faster than the vinyldialkylboranes with cyclopentadiene. Vinyl-9-BBN is the most regioselective dienophile, in keeping with principally steric control of regioselectivity
Vinylboranes are omniphilic dienophiles. Some unusual and useful properties of vinylboranes in diels-alder reactions
作者:Daniel A. Singleton、Jose P. Martinez、José V. Watson
DOI:10.1016/s0040-4039(00)91848-3
日期:1992.2
The rate of Diels-Alder reactions with vinyl-9-BBN is uniquely insensitive to diene substituent effects, and high reactivity is observed with both electron-rich and electron-poor dienes. The regioselectivity of these reactions is controlled mainly by steric effects.