improved generation of chiral cationic iridium catalysts for the asymmetricisomerization of primaryallylicalcohols is disclosed. The design of these air‐stable complexes relied on the preliminary mechanistic information available, and on Charton analyses using two preceding generations of iridium catalysts developed for this highly challenging transformation. Sterically unbiased chiral aldehydes
Stereoselective synthesis of terminal 1,3-butadienes by the condensation reaction of aldehydes and ketones with .gamma.-trimethylsilyl-substituted allylboranes
作者:Kung K. Wang、Chin Liu、Yu Gui Gu、Friedrich N. Burnett、Prem D. Sattsangi
DOI:10.1021/jo00005a045
日期:1991.3
Allylboranes 7-12, readily prepared from allenylsilanes 1-6 by hydroboration with 9-borabicyclo[3.3.1]nonane, smoothly condense with aldehydes and ketones to afford, after basic or acidic workup to promote the Peterson olefination reaction, a variety of terminal 1,3-butadienes. The dienes derived from aldehydes have high isomeric purity except in the cases with allylborane 12. Apparently, high diastereoselectivity was obtained during the condensation step with 7-11 to form 14. In each case, by simply changing the workup conditions to induce syn or anti elimination of hydroxytrimethylsilane, either the Z or the E isomer of the diene was obtained.
KIM, KEE D.;MAGRIOTIS, PLATO A., TETRAHEDRON LETT., 31,(1990) N3, C. 6137-6140
作者:KIM, KEE D.、MAGRIOTIS, PLATO A.
DOI:——
日期:——
WANG, KUNG K.;LIU, CHIN;GU, YU GUI;BURNETT, FRIEDRICH;N. , SATTSANGI PREM+, J. ORG. CHEM., 56,(1991) N, C. 1914-1922
作者:WANG, KUNG K.、LIU, CHIN、GU, YU GUI、BURNETT, FRIEDRICH、N. , SATTSANGI PREM+