Base-catalyzed diborylation of alkynes: synthesis and applications of cis-1,2-bis(boryl)alkenes
作者:Zhijie Kuang、Guoliang Gao、Qiuling Song
DOI:10.1007/s11426-018-9344-4
日期:2019.1
An efficient, transition-metal free, and practical approach to cis-bis(boryl)alkenes from various alkynes was disclosed in the presence of a catalytic amount of K2CO3 under mild conditions. Meanwhile, tetrasubstituted alkenes and phenanthrene derivatives were readily constructed from the target diborylalkenes via Suzuki-Miyaura cross coupling.
公开了在温和条件下在催化量的K 2 CO 3存在下从各种炔烃制得的有效,无过渡金属且实用的方法来从各种炔烃中制备顺式-双(硼基)烯烃。同时,通过铃木-宫浦(Suzuki-Miyaura)交叉偶合容易地由目标二硼烷基烯烃构建四取代的烯烃和菲衍生物。
Iridium-Catalyzed Enantioselective Hydrogenation of Alkenylboronic Esters
作者:Adnan Ganić、Andreas Pfaltz
DOI:10.1002/chem.201200246
日期:2012.5.29
iridium complex derived from a phosphino–imidazoline ligand is a highly efficient catalyst for the asymmetric hydrogenation of terminal vinyl boronic esters (see scheme). On the other hand, trisubstituted alkenyl‐boronates can be reduced with high activity and good to excellent enantioselectivity employing a pyridine–phosphinite ligand.
Mixed Diboration of Alkynes Catalyzed by LiOH: Regio- and Stereoselective Synthesis of <i>cis-</i>1,2-Diborylalkenes
作者:Sihan Peng、Guixia Liu、Zheng Huang
DOI:10.1021/acs.orglett.8b02830
日期:2018.12.7
A diboration of terminal alkynes with an unsymmetrical diboron reagent pinBBdan has been achieved using LiOH as the catalyst in the presence of stoichiometric amounts of MeOH, affording 1,2-diborylalkenes with different boryl groups. The reaction proceeds in a highly regio- and stereoselective manner through cis-addition of pinBBdan to the C–C triple bond, with the Bdan moiety being incorporated at
alkynes and alkenes undersolvent‐ and ligand‐freeconditions in air. The cis‐1,2‐diborylalkenes and 1,2‐diborylalkanes were obtained in moderate to excellent yields following, in most cases, a simple filtration workup protocol. The versatility of the cis‐1,2‐diboronvinyl compounds was demonstrated in a series of organic transformations, including the Suzuki–Miyauracrosscoupling and the boron–halogen
Catalytic Enantioselective Hydrogenation of Vinyl Bis(boronates)
作者:Jeremy B. Morgan、James P. Morken
DOI:10.1021/ja044396g
日期:2004.12.1
Catalytic enantioselectivehydrogenation of prochiral vinylmetallic reagents can provide an attractive alternative to hydrometalation and bismetalation of alkenes. In this contribution, the first highlyenantioselectivehydrogenation of vinyl boronic esters is described. The chiral reduction products are versatile intermediates for chemical synthesis.