Abstract
The synthesis of the first phosphirane was reported in 1963 and the synthesis of the first phosphirene in 1982. Since then, the chemistry of these systems and their related derivatives (phosphirene imides, phosphiranium, phoshirenium, and phosphirenylium salts) has been under intense investigations. In contrast to 1H-azirines, 1H-phosphirenes are not antiaromatic, since phosphorus has a pyramidal configuration which prevents full conjugation. Phosphirenium ions are stabilized energetically by σ*-aromaticity and the parent phosphoranylium ion is an aromatic 2π-system. The halo substituent of 1-halophosphirenes can easily exchange by a nucleophilic substitution process yielding a series of new phosphirenes. Some phosphiranes, especially if incorporated in a polycylic system, form transient metal complexes which are active catalysts. Stable phosphirane and phosphirene complexes were obtained by trapping transient terminal phosphinidene complexes, generated either from 7-phosphanorbornadiene or azaphosphirene complexes of group 6 transient metals with alkenes or alkynes, respectively. Free phosphiranes or phosphirenes were obtained by mild decomplexation of the corresponding complexes. Reduction of phosphirenium salts provides a further straightforward access to phosphirenes. Phosphaalkenes and phosphaalkynes are suitable starting materials for the synthesis of phosphiranes and phosphirenes by cycloaddition reactions with diazo compounds.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call