by oxidation with selenium dioxide and by Vilsmeier formylation. The 2-(2′-nitrovinyl)indoles have been obtained by condensa tion of 2-formylindoles with nitroalkanes in the presence of ammonium chloride in good yields. In this reac tion, only the (E)-isomer of the 2-(2′-nitrovinyl)indoles was observed by 1H nmr and NOE experiments. Evidence for an extended conjugation through the double bond and the
由合适的甲基吲哚通过用二氧化硒氧化并通过Vilsmeier甲酰化来制备2-甲酰基吲哚。通过在氯化铵存在下2-甲酰基吲哚与硝基烷烃的缩合反应以良好的收率获得了2-(2'-硝基乙烯基)吲哚。在该反应中,通过1 H nmr和NOE实验仅观察到2-(2'-硝基乙烯基)吲哚的(E)异构体。通过双键和硝基延长共轭的证据可以通过对烯烃质子的去屏蔽作用来评估。此外,在紫外可见光谱中的非啤酒定律行为表明这些化合物存在某种复合物。
Diborane as a reducing agent - VI the novel reduction of indole-1-carboxaldehydes to 1-methyl- indoles, di(indolyimethyl) ethers and indolylmethyl indolines
作者:Kshetra M. Biswas、Rabindranath Dhara、Sumita Roy、Haimanti Mallik
DOI:10.1016/s0040-4020(01)98809-x
日期:——
ether() and the indolenine () as the minor products, except . This appears to be the first report on the formation of symmetric ethers in the borane/THF reduction of an oxygen function. The formation of and from and implies that electrophilicsubstitution takes place primarily at position 3 of 3-substitutedindoles, did not form the corresponding probably because of steric hindrance. These results are