Borylation of Propargylic Substrates by Bimetallic Catalysis. Synthesis of Allenyl, Propargylic, and Butadienyl Bpin Derivatives
摘要:
Bimetallic Pd/Cu and Pd/Ag catalytic systems were used for borylation of propargylic alcohol derivatives. The substrate scope includes even terminal alkynes. The reactions proceed stererospecifically with formal S(N)2' pathways to give allenyl boronates. Opening of propargyl epoxides leads to 1,2-diborylated butadienes probably via en allenylboronate intermediate.
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