The Conversion of Carbonyl Compounds into Pentadienylamines by a Julia-Kocienski Olefination Procedure
作者:Richard Taylor、Reyhan Bastin、Mélanie Liron
DOI:10.1055/s-2008-1078011
日期:2008.8
Julia-Kocienski olefination has been successfully employed to convert carbonylcompounds into the corresponding Boc-protected 1,3-pentadienyl amines in a C 4 N homologation process. Good to excellent yields are achieved in THF using MHMDS as base to deprotonate the precursor l-phenyl-1H -tetrazol-5-ylsulfone reagent. The nature of the metallic countercation dramatically affects the stereoselectivity
Julia-Kocienski 烯化已成功用于在 C 4 N 同系化过程中将羰基化合物转化为相应的 Boc 保护的 1,3-戊二烯基胺。使用 MHMDS 作为碱使前体 1-苯基-1H-四唑-5-基砜试剂去质子化,在 THF 中实现了良好到极好的产率。金属抗衡阳离子的性质显着影响新形成的烯烃的立体选择性:使用 KHMDS 实现了良好水平的 2E,4E-立体选择性,而 LiHMDS 提供了 2E,4Ζ-二烯基产物的优势。
Benzotriazole-Mediated Stereoselective Olefination of Carboxylic Esters: Transformation of α-Amino Acid Esters into Chiral Allylamines
作者:Alan R. Katritzky、Dai Cheng、Jianqing Li
DOI:10.1021/jo971546f
日期:1998.5.1
Diastereoselective trans-olefinations of carboxylic esters 3a-h have been accomplished using benzylic or allylic benzotriazole derivatives la-e to prepare alpha-(benzotriazol-1-yl) ketones 4a-i, for the subsequent reduction of 4a-i, and finally for low-valent titanium-effected dehydroxybenzotriazolylation.(1) N-Protected alpha-amino acid esters 9a-c and 15 thus give allylamines 13a-e and 19 with virtually full retention of chirality. Mechanistic aspects of the dehydroxybenzotriazolylation are discussed.
MEYERS A. I.; LAWSON J. P.; CARVER D. R., J. ORG. CHEM., 1981, 46, NO 15, 3119-3123