<i>trans</i>-Hydroalumination/Alkylation: One-Pot Synthesis of Trisubstituted Allylic Alcohols
作者:Neil F. Langille、Timothy F. Jamison
DOI:10.1021/ol0613721
日期:2006.8.1
Described herein is a method of stereoselective synthesis of trisubstituted allylic alcohols by alkylation of alkenyl alanates, formed in situ through treatment of propargyl alcohols with Vitride (Red-Al). This technique represents the first of its kind to feature a trans-hydrometalation, and is particularly effective for the formation of 1,4-dienes. Applications involving primary, secondary, and tertiary alcohols are discussed, as well as limitations regarding both alkyne and electrophile components.
ISHINO, YOSHIO;WAKAMOTO, KOHJI;HIRASHIMA, TSUNEAKI, CHEM. LETT., 1984, N 5, 765-768
Bistrichloroacetimidates derived from 2-substituted but-2-ene-1,4-diols are transformed into 4-substituted 4-vinyloxazolines in high yields and excellent regioselectivities when Lewis acids AlCl3, FeCl3, TMSOTf, BF3ËOEt2, and AgBF4 are used as catalysts as well as with the Pd(PPh3)2Cl2/AgBF4 catalytic system. Lower regioselectivity is achieved with a neutral PdCl2(MeCN)2 catalyst and this could be a consequence of a switch to a competitive but less selective reaction mechanism. It is demonstrated that 4-substituted 4-vinyloxazolines can be efficiently transformed to N-Boc-protected C -quaternary vinylglycinols in a one-pot procedure.