Insertion of carbon fragments into P(III)-N bonds in aminophosphines and aminobis(phosphines): synthesis, reactivity, and coordination chemistry of resulting phosphine oxide derivatives. Crystal and molecular structures of (Ph(2)P(O)CH(2))(2)NR (R = Me, (n)Pr, (n)Bu), Ph(2)P(O)CH(OH)(n)()Pr, and cis-[MoO(2)Cl(2)((Ph(2)P(O)CH(2))(2)NEt-kappaO,kappaO)].
Reactions of N-aryl and N-alicyclic derivatives of aminophosphines with paraformaldehyde lead to methylene insertion into P-N bond followed by oxidation of phosphorus from the P(III) to P(V) state. When N-alkyl derivatives are reacted with paraformaldehyde, dimerization takes place to afford bis(phosphine oxide)s of the type Ph(2)P(O)CH(2)N(R)CH(2)P(O)Ph(2) (R = Me, (n)Pr, (n)Bu). Aminobis(phosphines) also undergo methylene insertion when treated with paraformaldehyde to give bis(phosphine oxides) Ph(2)P(O)CH(2)N(R)CH(2)P(O)Ph(2) (R = Me, Et, (n)()Pr, (i)()Pr, (n)Bu) in good yield. The reaction of aminophosphines with aromatic aldehydes ArCHO leads to insertion of "ArCH" into the P-N bond to give Ph(2)P(O)CH(R)N(H)Ph (R = C(6)H(5), furfuryl, o-C(6)H(4)OH), but with aliphatic aldehydes such as butanal, P-N bond cleavage takes place to afford alpha-hydroxy phosphine oxide. The reaction of aminobis(phosphines) with both aromatic and aliphatic aldehydes leads to the formation of alpha-hydroxy phosphine oxides through P-N bond cleavage whereas the reaction with furfural leads to the P-N bond insertion. The structure of the alpha-hydroxy derivative Ph(2)P(O)CR(H)(OH)(n)()Pr shows intermolecular hydrogen bonding between OH and P=O oxygen. The phosphine oxide derivatives act as bidentate ligands and form chelate complexes with Co(II), Mo(VI), Th(IV), and U(VI) derivatives. The crystal structure of the molybdenum complex, cis-[MoO(2)Cl(2)((OPPh(2)CH(2))(2)NEt-kappaO,kappaO)], shows the distorted octahedral geometry around Mo with two oxo groups cis to each other.
Priya
Srinivasan
S
Department of Chemistry, Indian Institute of Technology, Bombay, Mumbai 400 076, India.
Balakrishna
Maravanji S
MS
Mague
Joel T
JT
Mobin
Shaikh M
SM