Asymmetric Allylboration of Ketones Catalyzed by Chiral Diols
作者:Sha Lou、Philip N. Moquist、Scott E. Schaus
DOI:10.1021/ja0651308
日期:2006.10.1
Chiral BINOL-derived diols catalyze the enantioselective asymmetricallylboration of ketones. The reaction requires 15 mol % of 3,3‘-Br2-BINOL as the catalyst and allyldiisopropoxyborane as the nucleophile. The reaction products are obtained in good yields (76−93%) and high enantiomeric ratios (95:5−99.5:0.5). High diastereoselectivities (dr ≥ 98:2) and enantioselectivities (er ≥ 98:2) are obtained
The stereoselective crotylboration of alpha-oxocarboxylic acids
作者:Zhe Wang、Xian-Jun Meng、George W. Kabalka
DOI:10.1016/s0040-4039(00)93527-5
日期:1991.10
acids in a highly stereocontrolled manner. The reaction presumably proceeds through a bicyclictransitionstate. The alpha-carboxylic substituent exerts a remarkable effect on the rate, regio- and stereoselectivities of the reaction; homoallylic alpha-hydroxycarboxylic acids are formed with regio- and stereoselectivities approach 100%.
Stereoselective allyl- and crotylboration of alpha-hydroxyketones via neighboring group control
作者:Zhe Wang、Xian-Jun Meng、George W. Kabalka
DOI:10.1016/0040-4039(91)85008-s
日期:1991.4
Allylboronates and crotylboronates react with alpha-hydroxyketones to yield tertiary homoallylic alcohols in a highly stereocontrolled manner. The reaction presumably proceeds via a rigid bicyclic transition state. The alpha-hydroxy substituent exerts a remarkable and predictable effect on the diastereoselectivity of the reaction. Homoallylic alcohols are formed with diastereoselectivities approaching 100%.