Synthesis and Rearrangement of P ‐Nitroxyl‐Substituted P III and P V Phosphanes: A Combined Experimental and Theoretical Case Study

Low‐temperature generation of P ‐nitroxyl phosphane 2 (Ph 2 POTEMP), which was obtained by the reaction of Ph 2 PH ( 1 ) with two equivalents of TEMPO, is presented. Upon warming, phosphane 2 decomposed to give P ‐nitroxyl phosphane P ‐oxide 3 (Ph 2 P(O)OTEMP) as one of the final products. This facile synthetic protocol also enabled access to P ‐sulfide and P ‐borane derivatives 7 and 13 , respectively, by using Ph 2 P(S)H ( 6 ) or Ph 2 P(BH 3 )H ( 11 ) and TEMPO. Phosphane sulfide 7 revealed a rearrangement to phosphane oxide 8 (Ph 2 P(O)STEMP) in CDCl 3 at ambient temperature, whereas in THF, thermal decomposition of sulfide 7 yielded salt 10 ([TEMP‐H 2 ][Ph 2 P(S)O]). As well as EPR and detailed NMR kinetic studies, indepth theoretical studies provided an insight into the reaction pathways and spin‐density distributions of the reactive intermediates.