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Upstream product

• 72091-01-1 (RS)-o-phenylenebis(methylphenylphosphine) 
• 72098-92-1 (RS)-2,3-dihydro-1,3-dimethyl-1,3-diphenyl-1,3-diphosphoniaindene bis(hexafluorophosphate) 
• 72098-92-1 (RR;SS)-2,3-dihydro-1,3-dimethyl-1,3-diphenyl-1,3-diphosphoniaindene bis(hexafluorophosphate) 
• 72091-03-3 (RR;SS)-2,3-dihydro-1,3-dimethyl-1,3-diphenyl-1,3-diphosphoniaindene dibromide 
• 72091-03-3 (RS)-2,3-dihydro-1,3-dimethyl-1,3-diphenyl-1,3-diphosphoniaindene dibromide 

Relevant academic research and scientific papers

Carbodiphosphorane Isomers Based on a 1,3-Diphosphaindane Skeleton, and Their Precursors

In a search for ring-strained carbodiphosphoranes , the diastereomeric bis-phosphanes 1a(RR, SS, RS) and the symmetrical analogue 1c have been converted into the corresponding cyclic methylene-bridged bis-phosphonium bromides 2a,c and hexafluorophosphates 2b. 2a(RR;SS) and 2a(RS) were separated by fractional crystallization.Treatment of 2a-c with base (NH3 or n-BuLi) yields, in a first step, the semi-ylide salts 3a-c which, unexpectedly, undergo hydrolytic or ammonolytic cleavage at the ylidic PCHP bridge resulting in formation of the phosphane oxide or phosphane imine salts 5a, c and 6a, respectively.The second deprotonation step, using (C2H5)3P=CHCH3 as a transylidating agent, affords the conjugated bis-ylide 7a in the case of 2a, 3a(RS), but gives the carbodiphosphorane 4c in the case of the methyl-free 2c, 3c.With n-BuLi, 2a(RS) also yields the analogous species 4a(RS), probably as an Li(+) adduct, as proven by its conversion into the symmetrical methylated product 8a(RS).- 1c is methylated with CH3I at one P centre only.The resulting phosphonium salt 10 gives the mono-ylide 11 on treatment with NaNH2.