Reactions of (vinylimino)-λ5-phosphanes and related compounds. Part 29. Synthesis and chemical and structural properties of 11H-cyclohepta[b]indeno[2,1-d]pyrrole and acenaphtho[1,2-b]cyclohepta[d]pyrrole

Abstract

The reaction [(inden-3-yl)imino]- and [(acenaphthylen-1-yl)imino]-tributyl-λ⁵-phosphanes with 2-chlorotropone gave novel 11H-cyclohepta[b]indeno[2,1-d]pyrrole 2 and acenaphtho[1,2-b]cyclohepta[d]pyrrole 5, respectively. A deuterium exchange reaction of 2 suggested the intermediacy of 18π electronic anion 3. Compound 2 was converted into 11H-cyclohepta[b]indeno[2,1-d]pyrrol-11-one 14 and -11-ol 13. These compounds are stable in acidic media and no 16π electronic system 4 was observed. Compound 5 is composed of naphthalene and 1-azaazulene moieties. The reduction potentials and the basicities of 2, 13, 14 and 5 were measured to clarify their electronic properties and are discussed on the basis of AM1 calculations.