Tetra-cationic imidazoliumyl-substituted phosphorus–sulfur heterocycles from a cationic organophosphorus sulfide

Abstract

The reaction of imidazoliumyl-substituted P((III)) cations of type [L((R,Me))PCl2](+) (3a,b(+); L(R,Me) = imidazolium-2-yl a: R = Me; b: R = iPr) with (Me3Si)2S leads to the formation of tetra-cationic, eight-membered phosphorus sulfur heterocycles [L((R,Me))PS]4(4+) (9a,b(4+)), which can be explained by the tetramerization of the intermediately formed cationic phosphorus monosulfide [L((R,Me))PS](+) (8a,b(+)). The P4S4 ring adopts a crown conformation as observed for cyclo-S8. The Lewis base DMAP (4-dimethylaminopyridine) initiates a deoligomerization- and dismutation reaction of 9a,b(4+) to give P((I)) centered cation [L((R,Me))2P](+) (12a,b(+)) and phosphorus disulfide [(DMAP)2PS2](+) (14(+)).

Isolation and Characterization of the Free Phenylphosphinidene Chalcogenides C6H5P=O and C6H5P=S, the Phosphorous Analogues of Nitrosobenzene and Thionitrosobenzene

“…As found for phosphinidene oxides and sulfides, dioxophosphoranes (phosphinidene dioxides, R−PO 2 ) and thiooxophosphoranes (R−PS 2 ) are unstable molecules thought to be generated in the thermolysis of suitable organophosphorus precursors . These transient species are highly electrophilic at the phosphorus atom and have thus found use as efficient phosphorylating agents.…”

Preparation and Characterization of P2BCh Ring Systems (Ch=S, Se) and Their Reactivity with N‐Heterocyclic Carbenes

“…The recently reported 6‐membered phosphorus‐chalcogen rings 9Ch (Scheme , bottom) contain the same general formula as 1Ch (i.e. (RPCh) n ) and have long been considered as precursors to phosphinidene chalcogenides, although no experimental evidence has supported this claim. We utilized the same approach employed for 1Ch and 3Ch , and attempted the degradation of these larger P−Ch heterocycles into base‐stabilized phosphinidene chalcogenides using NHCs.…”

Recent Advances in Imidazoliumyl‐Substituted Phosphorus Compounds

“…The reaction of 96 a , b [OTf] with (Me 3 Si) 2 S gives the triflate salts of tetracationic, eight‐membered phosphorus sulfur heterocycles 99 a , b 4+ (Scheme ) . The formation of these compounds can be rationalized by a tetramerization reaction of the intermediately formed cationic mono (thioxo)phosphane 100 + .…”

“…The reaction of 96 a,b[OTf] with (Me 3 Si) 2 Sg ives the triflate salts of tetracationic, eight-membered phosphorus sulfur heterocycles 99 a,b 4 + (Scheme 30). [82] The formationo ft hesec ompounds can be rationalized by at etramerization reaction of the intermediately formed cationic mono (thioxo)phosphane 100 + .T he 31 PE XSY (exchange spectroscopy)N MR experiments of the dissolved compounds 99 a,b[OTf] 4 suggestt wo conformationali somers (crown( C 4v )v s. boat-chair (C S )) in solution in which one of the sulfur bridges reversibly changes its relative position. [82] However,t he molecular structures of the P 4 S 4 rings in tetracations 99 a,b 4 + adopt ac rown conformationa so bserved for cyclo-S 8 .…”