Transition-Metal-Mediated Cascade Reactions: The Water-Accelerated Carboalumination−Claisen Rearrangement−Carbonyl Addition Reaction
作者:Peter Wipf、David L. Waller、Jonathan T. Reeves
DOI:10.1021/jo051211v
日期:2005.9.1
water-accelerated catalytic carboalumination, a Claisen rearrangement, and a nucleophilic carbonyl addition converts terminal alkynes and allyl vinyl ethers into allylic alcohols containing up to three contiguous asymmetric carbon centers. Stoichiometric quantities of water as an additive increase the rate of the [3,3] sigmatropicrearrangement as well as the diastereoselectivity of the carbonyl addition
Highly regioselective [3,3] rearrangement of aliphatic allyl vinyl ethers catalyzed by a metalloporphyrin complex, Cr(TPP)Cl
作者:Toshikatsu Takanami、Mikiko Hayashi、Kazuhiro Iso、Hirose Nakamoto、Kohji Suda
DOI:10.1016/j.tet.2006.07.051
日期:2006.10
Claisen rearrangement of simple aliphatic allyl vinyl ethers catalyzed by a metalloporphyrin, Cr(TPP)Cl, is described. The porphyrin-based Lewis acid catalyst can effectively accelerate the rearrangement via a concerted [3,3] pathway with a minimal degree of bond ionization of the substrates, providing the corresponding Claisen products in moderate to high yields and almost perfect regioselectivity at low