The first catalytic enantioselective allylic substitution reaction with alkylboron compounds has been achieved. The reaction between alkyl-9-BBN reagents and primary allylic chlorides proceeded with excellent γ-selectivities and high enantioselectivities under catalysis of a Cu(I)-DTBM-SEGPHOS system. The protocol produces terminal alkenes with an allylic stereogenic center branched with functionalized
We have presented full details of our work on alkylboranes, which we have introduced as new reagents for copper-catalyzed SN2′-type enantioselectiveallylicsubstitutions. The copper catalysis delivered enantioenriched chiral products containing tertiary or quaternarycarbonstereogeniccenters branched with functionalized sp3-alkyl groups. The wide availability of alkylboranes via the established
我们已经介绍了我们在烷基硼烷上的全部工作细节,我们已将其引入作为铜催化的S N 2'型对映选择性烯丙基取代的新试剂。铜催化递送了富含对映体的手性产物,该手性产物包含带有官能化的sp 3-烷基的叔碳或季碳立体异构中心。通过已建立的烯烃加氢硼化反应,烷基硼烷的广泛可用性是这些转化的吸引人的特征。基板中可以容忍各种官能团。提出了一种通过烯丙基氯底物加成-消除中性烷基铜(I)物种的反应途径。
An enzyme-triggered enantio-convergent cascade-reaction
作者:Sandra F. Mayer、Andreas Steinreiber、Romano V.A. Orru、Kurt Faber
DOI:10.1016/s0957-4166(01)00010-6
日期:2001.2
The biocatalytic hydrolysis of the (+/-)-2,3-disubstituted cis-chloroalkyl epoxides 1a and 2a using resting cells of Rhodococcus sp. did not give the corresponding chloroalkyl vic-diols 1b, and 2b, respectively, but furnished the rearranged products (2R,3R)-1c and (2R,3R)-2c in high e.e. as the sole products via an enzyme-triggered enantio-convergent cascade-reaction. (C) 2001 Published by Elsevier Science Ltd. All rights reserved.
Allylic Chlorides. XXVI. The 1-Chloro-2-heptenes and 1-Chloro-4,4-dimethyl-2-pentenes
作者:LEWIS F. HATCH、HERBERT D. WEISS、TAO PING LI
DOI:10.1021/jo01060a013
日期:1961.1
Preparation of functionally substituted allenes from methylacetylenes via propargylic lithium alanate or lithium borate intermediates