Electronic properties of tri-, tetra-, and pentacoordinate phosphorus substitutents

Pyramidal Inversion at Phosphorus Facilitated by the Presence of Proximate Lewis Acids. Coordination Chemistry of Group 13 Elements with the Macrocyclic Bis(amidophosphine) Ligand [P2N2] ([P2N2] = [PhP(CH2SiMe2NSiMe2CH2)2PPh])

“…Consequently, the p-orbital can engage in overlap with orbitals on adjacent atoms to stabilize the transition state and lower the barrier to inversion. Most often this interaction has been viewed as a π-overlap as in arylphosphines (p π −p π ), ,, diphosphines, ,,− or silylphosphines (p π −d π ). , For arylphosphines, a lowering of the barrier of approximately 2−3 kcal mol -1 per aryl substituent 1 has been estimated. Incorporation of the phosphorus center into a phosphole ring results in 6π-electron systems in which electron delocalization is at a maximum in the planar transition state relative to the pyramidal ground state. − This results in barriers to inversion most often in the range of 15−18 kcal mol -1 .…”

Phosphonitrilic derivatives. XX. Electronic properties of fluorophosphonitrilic substituents

“…The parameters have also been shown to be applicable to substitution at a phosphorus center. 22 The 1SF chemical shifts of the fluorophenyl parts of the new compounds are given in Table III. ppm relative to CC13F (internal standard).…”

A “green” variation of the Hirao reaction: the P–C coupling of diethyl phosphite, alkyl phenyl-H-phosphinates and secondary phosphine oxides with bromoarenes using a P-ligand-free Pd(OAc)2catalyst under microwave and solvent-free conditions

“…All aryldiphenylphosphine oxides (4a-d) have been known from the literature. [48][49][50][51] Finally, a few dialkylphenylphosphine oxides (6a-c) were synthesized by the reaction of dialkylphosphine oxides (5a-c) with bromobenzene under the conditions of the P-ligand-free Hirao reaction at 175 C (Scheme 5). It was advantageous to use acetonitrile as the solvent to avoid the decomposition observed under solvent-free conditions.…”