Positional Selectivity in C–H Functionalizations of 2-Benzylfurans with Bimetallic Catalysts

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• 作者：Jiadi Zhang ; Sheng-Chun Sha ; Ana Bellomo ; Nisalak Trongsiriwat ; Feng Gao ; Neil C. Tomson ; Patrick J. Walsh
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：March 30, 2016
• 年：2016
• 卷：138
• 期：12
• 页码：4260-4266
• 全文大小：499K
• ISSN：1520-5126

文摘

Metal-catalyzed carbon–carbon bond-forming reactions are a mainstay in the synthesis of pharmaceutical agents. A long-standing problem plaguing the field of transition metal catalyzed C–H functionalization chemistry is control of selectivity among inequivalent C–H bonds in organic reactants. Herein we advance an approach to direct site selectivity in the arylation of 2-benzylfurans founded on the idea that modulation of cooperativity in bimetallic catalysts can enable navigation of selectivity. The bimetallic catalysts introduced herein exert a high degree of control, leading to divergent site-selective arylation reactions of both sp² and sp³ C–H bonds of 2-benzylfurans. It is proposed that the selectivity is governed by cation−π interactions, which can be modulated by choice of base and accompanying additives [MN(SiMe₃)₂, M = K or Li·12-crown-4].