of aldehyde by the catalysis of a chiraltitaniumcomplex derived from DTBP-H8-BINOL. The reaction is performed with good stoichiometry [1.5 equiv each of Grignard reagents and ClTi(OiPr)3] at a low catalyst loading (2 mol %), affording a variety of chiral secondary alcohols in high enantioselectivity and yields and, hence, realizing an asymmetric version of the Grignard reaction in an indirect manner
由格氏试剂和ClTi(O i Pr)3原位生成的烷基钛试剂可通过催化衍生自DTBP-H 8 -BINOL的手性钛配合物用于醛的对映选择性烷基化反应,而无需进一步操作。该反应以良好的化学计量[1.5当量的格氏试剂和ClTi(O i Pr)3 ]在低催化剂负载量(2mol%)下进行,从而以高对映选择性和收率提供了多种手性仲醇,因此,间接实现格氏反应的不对称形式。
Tandem α-Alkylation/Asymmetric Transfer Hydrogenation of Acetophenones with Primary Alcohols
作者:Oleksandr O. Kovalenko、Helena Lundberg、Dennis Hübner、Hans Adolfsson
DOI:10.1002/ejoc.201403032
日期:2014.10
A tandem -alkylation/asymmetric transferhydrogenation of acetophenones with primary alcohols, mediated by a single ruthenium catalyst, is described. Under optimized reaction conditions and with use of [Ru(p-cymene)Cl-2](2) in combination with an amino acid hydroxyamide ligand, the chiral secondary alcohol products were isolated in moderate yields and in moderate to good enantiomeric excess (up to