Cyclic (Alkyl)(amino)carbene Ligands Enable Cu‐Catalyzed Markovnikov Protoboration and Protosilylation of Terminal Alkynes: A Versatile Portal to Functionalized Alkenes**
作者:Yang Gao、Sima Yazdani、Aaron Kendrick、Glen P. Junor、Taeho Kang、Douglas B. Grotjahn、Guy Bertrand、Rodolphe Jazzar、Keary M. Engle
DOI:10.1002/anie.202106107
日期:2021.9
donating cyclic (alkyl)(amino)carbene (CAAC) ligands. Using this method, both alkyl- and aryl-substituted alkynes are coupled with a variety of boryl and silyl reagents with high α-selectivity. The reaction is scalable, and the products are versatile intermediates that can participate in various downstream transformations. Preliminary mechanistic experiments shed light on the role of CAAC ligands in this
<b>
Synthesis of Acrylonitriles
<i>via</i>
Mild Base Promoted Tandem Nucleophilic
<scp>Substitution‐Isomerization</scp>
of
<scp>α‐Cyanohydrin</scp>
Methanesulfonates
</b>
作者:Shiwen Liu、Lingling Meng、Xiaojun Zeng、Gerald B. Hammond、Bo Xu
DOI:10.1002/cjoc.202000579
日期:2021.4
Main observation and conclusion We have developed an efficient synthesis of acrylonitriles via mild base promoted tandem nucleophilic substitution‐isomerization of α‐cyanohydrin methanesulfonates with alkenylboronic acids. This transition metal‐free protocol works under simple and mild conditions and offers good chemical yields for a wide range of substrates and demonstrates good functional group tolerance
Cobalt‐Catalyzed Markovnikov‐Type Selective Hydroboration of Terminal Alkynes
作者:Jieping Chen、Xuzhong Shen、Zhan Lu
DOI:10.1002/anie.202012164
日期:2021.1.11
Markovnikov‐type hydroboration of terminal alkynes with HBpin to access α‐alkenyl boronates with good regioselectivity and atom economy is reported. A new ligand has been developed for the cobalt hydride catalyst that has been used for a unique Markovnikov selective insertion of terminal alkynes into metal hydride bond. This operationally simple protocol exhibits excellent functional group tolerance