A copper(II)-catalyzed borylation of alkyl halides with bis(pinacolato)diboron (B2pin2) has been developed, which can be carried out in air, providing a wide range of primary, secondary, and some tertiary alkylboronates in high yields. A variety of functional groups are tolerated and the protocol is also applicable to unactivated alkyl chlorides (including 1,1- and 1,2-dichlorides). Preliminary mechanistic
A regiospecific allyl–allylcoupling reaction between 1,3-dienes and allylboronates has been demonstrated under nickel catalysis. Salient features of this method include the earth-abundant metal catalyst, excellent regioselectivity and good functional group tolerance. Notably, even congested allyl substrates can also be applied to this protocol, thus allowing for the rapid preparation of a series of
Photoinduced Cross-Coupling of Aryl Iodides with Alkenes
作者:Yuliang Liu、Haoyu Li、Shunsuke Chiba
DOI:10.1021/acs.orglett.0c03935
日期:2021.1.15
A protocol for photoinduced cross-coupling of aryliodides having polar π-functional groups or elongated π-conjugation with alkenes has been developed. The radical cascade mechanism involving generation of aryl radicals via C–I bond homolysis of photoexcited aryliodides and their subsequent addition to alkenes is proposed. The method enables iodide-selective cross-coupling over other halogen leaving
Synthesis of Benzyl-, Allyl-, and Allenyl-boronates via Copper-Catalyzed Borylation of Alcohols
作者:Lujia Mao、Kálmán J. Szabó、Todd B. Marder
DOI:10.1021/acs.orglett.7b00256
日期:2017.3.3
Alcohols are among the most abundant and readily available organic feedstocks in industrial processes. The direct catalytic functionalization of sp3 C–O bonds of alcohols remains the main challenge in this field. Here, we report a copper-catalyzed synthesis of benzyl-, allyl-, and allenyl-boronates from benzylic, allylic, and propargylic alcohols, respectively. This protocol exhibits a broad reaction
Iridium-Catalyzed Enantioselective Allyl–Allyl Cross-Coupling of Racemic Allylic Alcohols with Allylboronates
作者:Yu Zheng、Bei-Bei Yue、Kun Wei、Yu-Rong Yang
DOI:10.1021/acs.orglett.8b03627
日期:2018.12.21
catalytic system that allows asymmetric allyl–allylboronate cross-coupling with high enantioselectivity is reported. This transformation tolerates a large variety of racemic branched allylicalcohols and allylboronate substrates. The utility of the coupling is demonstrated in a concise catalytic asymmetric synthesis of (−)-preclamol.