Asymmetric Alkynylation of Seven-Membered Cyclic Imines by Combining Chiral Phosphoric Acids and Ag(I) Catalysts: Synthesis of 11-Substituted-10,11-dihydrodibenzo[<i>b</i>,<i>f</i>][1,4]oxazepine Derivatives
作者:Yuan-Yuan Ren、You-Qing Wang、Shuang Liu
DOI:10.1021/jo5022037
日期:2014.12.5
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
Solvent-controlled and selective synthesis of mono- and bis-indolyl products in Brønsted acid catalyzed aza-Friedel–Crafts reactions of indoles with cyclic imines
dibenzo[b,f][1,4]oxazepines with various indoles have been carried out. In the presence of 10 mol % trifluoroacetic acid (TFA), the selectivity of this reaction can be controlled in different solvents, affording mono-indole substituted products in THF and bis-indole substituted products in DCM as major products. Unsymmetric bis-indole substituted products can be obtained via a sequential procedure. Structurally