NiH‐Catalyzed Migratory Defluorinative Olefin Cross‐Coupling: Trifluoromethyl‐Substituted Alkenes as Acceptor Olefins to Form
<i>gem</i>
‐Difluoroalkenes
a NiH-catalyzed migratory defluorinative coupling between two electronically differentiated olefins. A broad range of unactivated donor olefins can be joined directly to acceptor olefins containing an electron-deficient trifluoromethyl substituent in both intra- and intermolecular fashion to form gem-difluoroalkenes. This migratory coupling shows both site- and chemoselectivity under mild conditions
Copper-Catalyzed Carboxylation of Hydroborated Disubstituted Alkenes and Terminal Alkynes with Cesium Fluoride
作者:Martin Juhl、Simon L. R. Laursen、Yuxing Huang、Dennis U. Nielsen、Kim Daasbjerg、Troels Skrydstrup
DOI:10.1021/acscatal.6b03571
日期:2017.2.3
A protocol for the hydrocarboxylation of disubstituted alkenes and terminal alkynes providing access to different secondary carboxylicacids and malonic acid derivatives has been developed. This methodology relies on an initial hydroboration using 9-BBN followed by carboxylation with carbondioxide in the presence of a coppercatalyst and the additive, cesium fluoride. Different cyclohexene, styrene
Synthesis of Pyridines by Carbenoid-Mediated Ring Opening of 2<i>H</i>-Azirines
作者:Nicole S. Y. Loy、Alok Singh、Xianxiu Xu、Cheol-Min Park
DOI:10.1002/anie.201209301
日期:2013.2.18
a wide range of substituents on the resulting pyridinering using mild reaction conditions (see scheme; esp=α,α,α′,α′‐tetramethyl‐1,3‐benzenedipropionic acid). The formation of the key intermediate is catalyst‐controlled, and subsequent cyclization and oxidation affords pyridines in excellent yields. The method has been used for the efficient synthesis of polyarylpyridines.
Wacker‐Type Oxidation Using an Iron Catalyst and Ambient Air: Application to Late‐Stage Oxidation of Complex Molecules
作者:Binbin Liu、Fengli Jin、Tianjiao Wang、Xiaorong Yuan、Wei Han
DOI:10.1002/anie.201707006
日期:2017.10.2
air: A convenient and general iron-catalyzed oxidation of internal olefins, electron-deficient olefins, and styrenes to ketones by using 1 atm of air as the sole oxidant has been developed. This protocol efficiently incorporates atmospheric O2 into synthetically useful compounds under mild reaction conditions, which renders it environmentally benign, economical, and operationally simple.