Enantioselective Synthesis of Multisubstituted Allenes by Cooperative Cu/Pd‐Catalyzed 1,4‐Arylboration of 1,3‐Enynes

2019/11/28 by Yang Liao, Xuemei Yin, Xihong Wang +5
Chemistry · #Catalytic C–H Functionalization Methods #Organoboron and organosilicon chemistry #Asymmetric Hydrogenation and Catalysis

paper · doi:10.1002/ange.201912703

Abstract

Abstract A cooperative Cu/Pd‐catalyzed enantioselective synthesis of multisubstituted allenes is established. By employing chiral sulfoxide phosphine (SOP)/Cu and PdCl 2 (dppf) complexes as catalysts, the 1,4‐arylboration of 1,3‐enynes provides an efficient approach to trisubstituted chiral allenes with up to 92 % yield and 97:3 er. Furthermore, by using 2‐substituted 1,3‐enynes as substrates, the tetrasubstituted chiral allenes were successfully generated using this strategy. Finally, theoretical calculations indicate that the transmetallation of the allenylcopper species is the rate‐limiting step of this transformation.

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