Asymmetric 1,4-Dihydroxylation of 1,3-Dienes by Catalytic Enantioselective Diboration
作者:Heather E. Burks、Laura T. Kliman、James P. Morken
DOI:10.1021/ja809610h
日期:2009.7.8
studies reported in this communication suggest that both cyclic and acyclic substrates will participate in this reaction; however, dienes which are unable to adopt the S-cis conformation are unreactive. For most substrates, 1,4-addition is the predominant pathway. In addition to oxidation to the derived 2-buten-1,4-diol, stereoselective carbonyl allylation with the intermediate bis(boronate) ester is
The use of chiral alcohols to form the Lewis acid–base *RO− → bis(pinacolato)diboron adduct, in situ, provides an opportunity to induce asymmetry in the organocatalytic diboration of alkenes and complements the well established transition metal-mediated enantioselective diboration.
Modular Monodentate Oxaphospholane Ligands: Utility in Highly Efficient and Enantioselective 1,4-Diboration of 1,3-Dienes
作者:Christopher H. Schuster、Bo Li、James P. Morken
DOI:10.1002/anie.201102404
日期:2011.8.16
Tune it up! Tunable, chiral, monodentateoxaphospholaneligands (termed OxaPhos) are highly effective in the Pt‐catalyzed title reaction, providing the 1,4‐addition products in enantiomer ratios approaching 99:1 (see scheme). In the presence of enantiomerically pure cis‐iBu‐OxaPhos, a catalyst loading of only 0.02 mol % [Pt(dba)3] was sufficient for effective reaction. pin=pinacolato, dba=dibenzylideneacetone
作者:Lu Yan、Yan Meng、Fredrik Haeffner、Robert M. Leon、Michael P. Crockett、James P. Morken
DOI:10.1021/jacs.7b12316
日期:2018.3.14
A mechanistic investigation of the carbohydrate/DBU cocatalyzed enantioselective diboration of alkenes is presented. These studies provide an understanding of the origin of stereoselectivity and also reveal a strategy for enhancing reactivity and broadening the substrate scope.