Carbene and Acid Cooperative Catalytic Reactions of Aldehydes and o-Hydroxybenzhydryl Amines for Highly Enantioselective Access to Dihydrocoumarins.

@article{Chen2017CarbeneAA,
  title={Carbene and Acid Cooperative Catalytic Reactions of Aldehydes and o-Hydroxybenzhydryl Amines for Highly Enantioselective Access to Dihydrocoumarins.},
  author={Xingkuan Chen and Runjiang Song and Yingguo Liu and Chong Yih Ooi and Zhichao Jin and Tingshun Zhu and Hongling Wang and Lin Hao and Yonggui Robin Chi},
  journal={Organic letters},
  year={2017},
  volume={19 21},
  pages={
          5892-5895
        }
}
A highly enantioselective method for quick access to dihydrocoumarins is reported. The reaction involves a cooperative catalytic process with carbene and in situ generated Brønsted acid as the catalysts. α-Chloro aldehyde and readily available and stable o-hydroxybenzhydryl amine substrates were used to generate reactive azolium ester enolate and ortho-quinone methide (o-QM) intermediates, respectively, to form dihydrocoumarins with exceptionally high diastereo- and enantioselectivities. The… CONTINUE READING
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