Asymmetric alkynylation of seven-membered cyclic imines by combining chiral phosphoric acids and Ag(I) catalysts: synthesis of 11-substituted-10,11-dihydrodibenzo[b,f][1,4]oxazepine derivatives.
Asymmetric alkynylation of seven-membered cyclic imine dibenzo[b,f][1,4]oxazepines is successfully achieved by combining chiral phosphoric acid and Ag(I) catalysts. Various arylacetylenes, conjugated enynes, and terminal 1,3-diynes are good substrates for this reaction, and aliphatic hexyne is also a suitable donor at elevated temperature. Optimization of this approach has provided a facile method to synthesize optically active 11-substituted-10,11-dihydrodibenzo[b,f][1,4]oxazepine derivatives containing a carbon-carbon triple bond with 63-99% ee. Subsequent transformations of the carbon-carbon triple bond for the heterocyclic products have been disclosed.
Provincial Key Laboratory of Natural Medicine and Immuno-Engineering, Henan University , Kaifeng, Henan, 475004, China.
Yuan-Yuan
YY
Ren
You-Qing
YQ
Wang
Shuang
S
Liu
D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D007097:Imines / Q000737:chemistry*; D010077:Oxazepines / Q000138:chemical synthesis* / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013237:Stereoisomerism
C000599114:10,11-dihydrodibenzo(b,f)(1,4)oxazepine; D000480:Alkynes; D006571:Heterocyclic Compounds; D007097:Imines; D010077:Oxazepines; D010756:Phosphoric Acids; D012834:Silver; C030242:phosphoric acid