Catalytic Cyclization/Silylation of Dienes Containing 1,1-Disubstituted Olefins Using Organolanthanide and Group 3 Organometallic Complexes
摘要:
The catalytic cyclization/silylation reaction of hindered dienes has been investigated using the relatively unhindered complexes Me2Si(C5H3SiMe3)(2)YCH(TMS)(2) and [Cp(2)(TMS)LnMe](2) (Ln = Y, Lu). A nide variety of dienes and trienes bearing a number of functional groups were cyclized, affording silanes containing quaternary centers in a diastereoselective fashion and in good yield. The products can be oxidized using one of several different protocols, yielding alcohols for further functionalization.
High-Yielding and Rapid Carbon-Carbon Bond Formation from Alcohols: Allylation by Means of TiCl4
作者:Alfred Hassner、Chennakesava Bandi
DOI:10.1055/s-0033-1338746
日期:——
TiCl4 efficientlypromotes high yield (80–99%) replacement of OH in tertiary, benzylic, and allylic alcohols, and even nonactivated secondary alcohols, by an allyl group. The reaction usually proceeds within minutes at room temperature.