THE RELATIVE APICOPHILICITIES OF PSEUDOHALOGEN SUBSTITUENTS IN FIVE CO-ORDINATE PHOSPHORANES

Abstract
Variable temperature nmr spectroscopy on the 1:1-adduct of cyanodiphenylphosphine and perfluorobiacetyl and on the phosphoranes formed from tetrachloro-o-benzoquinone and various 2-substituted 4,4,5,5-tetramethyl-1,3,2-dioxaphospholans has led to an order of relative apicophilicity in these phosphoranes of CN > C1 ∼ NCO ∼ NCS > N3 > OPh. Hexafluoroacetone and 2-(2′,4′,6′-trimethylbenzoyl)-4,4,5,5-tetramethyl-1,3,2-dioxaphospholan gave the oxide (8).