Phosphorus-carbon bond forming reactions of iron tetracarbonyl-coordinated phosphenium ions

Abstract Abstraction of chloride from [Fe(CO) 4 (PPh 2 Cl)] ( 1 ) in the presence of PPh 3 leads to [Fe(CO) 4 (PPh 2 (PPh 3 ))][AlCl 4 ] ( 2 ), an iron complex of a phosphine-coordinated phosphenium ion. The PPh 3 is readily displaced by ferrocene, leading to an electrophilic aromatic substitution reaction, and formation of [Fe(CO) 4 {PPh 2 Fc}] ( 3 ) (Fc = ferrocenyl). Alternately, chloride abstraction from 1 in the presence of ferrocene leads directly to 3 , via a transient phosphenium ion complex. The transient phosphenium ion complex also reacts with N,N-diethylaniline, indole, and pyrrole to form the respective p -anilinyl, 3-indolyl, and 2-pyrryl phosphine complexes via electrophilic aromatic substitution. Chloride abstraction from [Fe(CO) 4 (PPhCl 2 )] in the presence of ferrocene leads to a double substitution reaction, forming [Fe(CO) 4 {PPhFc 2 }] ( 13 ).