摘要：

2-Vinyl-N,N-dialkylanilines react thermally in polar solvents and/or in the presence of Lewis acids via [1,5] or [1,6] hydrogen transfer followed by C-C bond formation to give heterotricyclic compounds. The reaction depends on the type of N,N-dialkylamino group and on the type and position of substituents of the vinyl moiety. 1-Pyrrolidinyl butenedioate 5a and (1-pyrrolidinyl)benzeneacetonitrile 7a undergo a thermal rearrangement to the pyrrolo[1,2-a]indoles 12a,b and 13a,b, respectively, while the 1-piperidinyl and 4-morpholinyl butenedioates 5b,c and the (4-morpholinyl)benzeneacetonitrile 7c do not react. The (1-piperidinyl)benzeneacetonitrile 7b yields in refluxing toluene in the presence of zinc chloride the pyrido[1,2-a]indole 14b and, by HCN elimination, pyrido[1,2-a]indole 15b. Under these conditions the cis- and trans-pyrrolo[1,2-a]indoles 13a and 13b also eliminate HCN to give 15a. Heating the 1-pyrrolidinyl propanedioate 10 and the 1-pyrrolidinyl, 1-piperidinyl, and 4-morpholinyl propanedinitriles 11a-c in 1-butanol gives the pyrrolo[1,2-a]quinolines 16a,b, benzo[c]quinolizine 17, and [1,4]oxazino[4,3-a]quinoline 18, respectively. The mechanisms of both types of cyclization, which are examples of the "tert-amino effect", are discussed.

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