Highly Regioselective Synthesis of Trisubstituted Allenes via Lithiation of 1-Aryl-3-alkylpropadiene, Subsequent Transmetalation, and Pd-Catalyzed Negishi Coupling Reaction
Jinbo Zhao, Yu Liu and Shengming Ma*
*Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, People's Republic of China, Email: masmmail.sioc.ac.cn
J. Zhao, Y. Liu, S. Ma, Org. Lett., 2008, 10, 1521-1523.
DOI: 10.1021/ol8001909 (free Supporting Information)
Lithiation of 1-aryl-3-alkylpropadienes and subsequent transmetalation with zinc bromide followed by Pd-catalyzed Negishi coupling reactions with halides afforded the corresponding trisubstituted allenes in a highly regioselective fashion with good yields. A plausible regioselective lithiation mechanism was proposed on the basis of deuterium labeling experiments.
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