Condensation Reactions of Chlorophosphanes with Chalcogenides

Abstract

A high-yielding and facile synthesis for diphosphane monochalcogenides (1(Ch)((R))) and their constitutional isomers, diphosphanylchalcoganes (2(Ch)((R))), was developed, featuring a condensation reaction between chlorophosphanes (R2PCl) and sodium chalcogenides (Na2Ch, Ch = S, Se, (Te)). The optimized protocol selectively yields either 1(Ch)((R)) (R2(Ch)PPR2) or 2(Ch)((R)) (Ch(PR2)2) depending upon the steric demand of the substituents R. Reaction pathways consistent with the distinct reaction outcomes are proposed. The application of 1(Ch)((R)) and 2(Ch)((R)) as an interesting class of ligands is exemplarily demonstrated by the preparation of selected transition metal complexes.

Exploiting the Ring Strain of Diphosphetanes: A Synthetic and Computational Approach towards 1,2,5‐Selenadiphospholanes

“…The C cluster −C cluster bond length as well as the bond angles around the phosphorus atoms in both compounds have similar values to those found in diphospholane diselenide III and are comparable to previously published carborane‐substituted bisphosphanes ,,. The P−Se and P=Se bond lengths as well as the P−Se−P angles observed in both compounds are within the range of published values for diphospholane diselenides Ia , Ib and III , as well as the open‐chain diphosphaselenanes VI . Furthermore, the envelope geometry of the C 2 P 2 Se rings is stabilised by several intramolecular C−H⋅⋅⋅Se interactions with H⋅⋅⋅Se distances ( 2‐ meso : 2.89–3.01 Å, 4‐ meso : 2.82–2.93 Å, Figure ) being well within the sum of the van der Waals radii (3.00 Å) .…”

“…Consequently, the 77 Se{ 1 H} NMR spectrum shows two triplets at 132.7 ( 2‐ meso ) and 178.4 ( 2‐ rac ) ppm with matching coupling constants. The measured coupling constants are within the range of values observed for P−Se single bonds ,. It is noteworthy that the 13 C{ 1 H} NMR spectrum can be analysed as a first‐order spectrum despite the formal presence of four ABX (cluster carbon atoms and the quaternary t Bu carbon atoms of each isomer) spin systems.…”

“…Ia , b were synthesised by reacting Woollins reagent with dienes, II was obtained by treatment of dppe with a Se II source and III was isolated as a side product in the reaction between ortho ‐carborane‐1,2‐bis(selenoate) and dichlorophenylphosphine . In contrast, the open‐chain analogues of selenadiphospholanes, diphosphaselenanes VI , are readily accessible by treatment of chlorophosphanes IV with sodium selenide or reaction of elemental selenium with diphosphanes V bearing bulky substituents (Scheme ) –. Part of the driving force of the latter reaction might be attributed to reduction of steric interaction.…”

Synthesis of Bis(phosphanyl)alkane Monosulfides by the Addition of Diphosphane Monosulfides to Alkenes under Light

“…Diphosphane monosulfide 4 a generated from Ph 2 PCl and (Me 3 Si) 2 S in situ was also effective in this reaction and gave 2.0 g of bis‐adduct 8 ag in 84 % yield (Scheme ).…”

“…The wide scope of 4 facilitates highly selective additions of unsymmetrically substituted diphosphane monosulfides to alkenes. Several unsymmetrical diphosphane monosulfides 4 h – 4 j were synthesized by a modification of the method reported by Burford, Weigand et al The starting diphosphanes can be used in the next step without strict purification (see Supporting Information), as shown in Table . The reaction of dicyclohexyl(diphenylphosphanyl)phosphane sulfide ( 4 h ) with 2 n afforded the corresponding BPSO 10 hn in good yield.…”