<i>B</i>-Allenyl- and <i>B-</i>(γ-Trimethylsilylpropargyl)- 10-phenyl-9-borabicyclo[3.3.2]decanes: Asymmetric Synthesis of Propargyl and α-Allenyl 3°-Carbinols from Ketones
作者:Eliud Hernandez、Carlos H. Burgos、Eyleen Alicea、John A. Soderquist
DOI:10.1021/ol061596j
日期:2006.8.1
Simple and efficient Grignard procedures are reported for the syntheses of B-allenyl-10-(phenyl)-9-borabicyclo[3.3.2]decane (1) and its B-(gamma-trimethylsilylpropargyl) counterpart (2) in both enantiomeric forms. Both add selectively to ketones, providing propargyl- and alpha-silylallenyl 3-degree-carbinols, respectively (i.e., 6 (61-93% ee) and 9 (64-98% ee)). The air-stable boron byproduct is efficiently
Three-Dimensional Correlation of Steric and Electronic Free Energy Relationships Guides Asymmetric Propargylation
作者:Kaid C. Harper、Matthew S. Sigman
DOI:10.1126/science.1206997
日期:2011.9.30
An unexpected synergy between a ligand's
steric bulk and its electronic structure improves a stereoselective catalyst.
一个配体的空间体积和电子结构之间意外产生的协同作用提高了立体选择性催化剂。
Prediction of Catalyst and Substrate Performance in the Enantioselective Propargylation of Aliphatic Ketones by a Multidimensional Model of Steric Effects
作者:Kaid C. Harper、Sarah C. Vilardi、Matthew S. Sigman
DOI:10.1021/ja4001807
日期:2013.2.20
The effectiveness of a new asymmetriccatalytic methodology is often weighed by the number of diverse substrates that undergo reaction with high enantioselectivity. Here we report a study that correlates substrate and ligand steric effects to enantioselectivity for the propargylation of aliphatic ketones. The mathematical model is shown to be highly predictive when applied to substrate/catalyst combinations
Method for preparing (+)R-2-methyl-hexane-1,2-diol
申请人:MILES INC.
公开号:EP0198352A2
公开(公告)日:1986-10-22
A method for preparing important stereospecific intermediates in the synthesis of prostaglandin analogs is disclosed. Said intermediates are (+)R-2-methyl-hexane-1,2-diol and (-)S-2-methyl-hexane-1,2-diol and are prepared via an asymmetric halolactonization reaction utilizing L-proline and D-proline, respectively as the chiral agent.