Clarification on the Reactivity of Diaryl Diselenides toward Hexacyclohexyldilead under Light

Abstract

In this study, the reactivity of organochalcogen compounds toward a representative alkyl-lead bond compound under light was investigated in detail. Under light irradiation, the Cy-Pb bond of Cy6Pb2 (Cy = cyclohexyl) undergoes homolytic cleavage to generate a cyclohexyl radical (Cy•). This radical can be successfully captured by diphenyl diselenide, which exhibits excellent carbon-radical-capturing ability. In the case of (PhS)2 and (PhTe)2, the yields of the corresponding cyclohexyl sulfides and tellurides were lower than that of (PhSe)2. This probably occurred due to the low carbon-radical-capturing ability of (PhS)2 and the high photosensitivity of the cyclohexyl-tellurium bond.

Heterometathesis of diphosphanes (R2P–PR2) with dichalcogenides (R′E–ER′, E = O, S, Se, Te)

“…The higher rate observed with the diselenide than with the disulfide reflects the ease with which homolysis of the weak Se–Se bond takes place compared to the homolysis of either the S–S or P–P bonds. 39–41…”

“…The higher rate observed with the diselenide than with the disulfide reflects the ease with which homolysis of the weak Se-Se bond takes place compared to the homolysis of either the S-S or P-P bonds. [39][40][41] Attempted diphosphane-ditelluride and diphosphaneperoxide metatheses When Ph 2 P-PPh 2 and PhTe-TePh were mixed in C 6 D 6 , no heterometathesis reaction (Scheme 2) was observed even after 12 days. The compound Ph 2 P-TePh has not been previously reported, although its P(V) isomer Ph 3 PvTe is readily prepared.…”

Recent Progress in Synthetic and Biological Application of Diorganyl Diselenides

“…In one case, light irradiation promoted the homolytic cleavage of CÀ Pb bond in the hexacyclohexyl lead compounds to generate a cyclohexyl radical, which diorganyl diselenides can capture to afford cyclohexyl aryl selenides 113 in good yields (Scheme 106). [164] Cross-coupling of diorganyl diselenides with aryl halides is suitable for preparing diorganyl selenides. In one approach, substituted arylselenoesters 114 were synthesized by employing palladium-catalyzed carbonylative cross-coupling of diaryl diselenides with aryl iodides (Scheme 107).…”

“…In one case, light irradiation promoted the homolytic cleavage of C−Pb bond in the hexacyclohexyl lead compounds to generate a cyclohexyl radical, which diorganyl diselenides can capture to afford cyclohexyl aryl selenides 113 in good yields (Scheme 106). [164] …”

Transition-Metal-Free Synthesis of Unsymmetrical Diaryl Tellurides via SH2 Reaction of Aryl Radicals on Tellurium

“…Aryl radicals generated in air by the oxidation of arylhydrazine hydrochlorides or photoirradiation of triarylbismuthines were successfully trapped with I 2 or BBr 3 in dimethyl sulfoxide (DMSO) to give the corresponding aryl halides with high yields ( Scheme 1 a,b) [ 5 , 6 ]. This system was also applicable for the formation of unsymmetrical sulfides and selenides by trapping aryl radicals with (R–X) 2 (X = S, Se) ( Scheme 1 c) [ 7 , 8 , 9 , 10 ]. In addition, we recently reported the preliminary results regarding the trapping of aryl radicals with diaryl ditellurides (ArTe) 2 [ 11 ].…”