A stereoselectivesynthesis of the C1–C16 segment of biofilm inhibitor carolacton has been achieved. The syntheticstrategy involves Sharpless asymmetric epoxidation, Roush crotylation, Steglich esterification, RCM reaction and selective reduction of a disubstituted olefin in the presence of a trisubstituted olefin using in situ generated diimide.
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 invention concerns compounds of general formula (X) in which Y represents in particular —CONHOH, R1 represents in particular a C1-C5 alkyl group, AA represents an amino acid, or an amino acid sequence, and R3 represents in particular a group of formula —NH—(CH2)2—SCH3. The invention also concerns the pharmaceutical compositions containing them, and the methods for obtaining them.
Asymmetric Allylboration of Acyl Imines Catalyzed by Chiral Diols
作者:Sha Lou、Philip N. Moquist、Scott E. Schaus
DOI:10.1021/ja075204v
日期:2007.12.1
is directly applied to the synthesis of Maraviroc, the selective CCR5 antagonist with potent activity against HIV-1 infection. Mechanistic investigations of the allylboration reaction including IR, NMR, and mass spectrometry studies indicate that acyclic boronates are activated by chiral diols via exchange of one of the boronate alkoxy groups with activation of the acyl imine via hydrogen bonding.
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%.