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Download fileOrganocatalyzed Asymmetric 1,6-Conjugate Addition of para-Quinone Methides with Dicyanoolefins
journal contribution
posted on 04.02.2016, 16:06 authored by Xuanyi Li, Xiuyan Xu, Weiwei Wei, Aijun Lin, Hequan YaoA chiral thiourea
catalyzed asymmetric 1,6-conjugate addition of para-quinone methides with dicyanoolefins has been developed.
The reaction provided an efficient approach to the synthesis of chiral
diarylmethine skeletons in good yields (up to 99% yield) with high
diastereo- and enantioselectivity (>20:1 dr and up to 99.5:0.5
er),
also on a gram scale. The preliminary mechanistic study showed that
the remote stereocontrol was achieved through intermolecular hydrogen-bond
interaction between the chiral thiourea catalyst and the para-quinone methides directly for the first time.