117984-82-4

Basic information

• Product Name: {((PP₃)Rh)2(PCHO)}(BPh₄)2
• Synonyms: {((PP₃)Rh)2(PCHO)}(BPh₄)2
• CAS NO: 117984-82-4
• Molecular Weight: 2475.96
• Mol File: 117984-82-4.mol

Chemical Properties

• CAS DataBase Reference: {((PP₃)Rh)2(PCHO)}(BPh₄)2(CAS DataBase Reference)
• NIST Chemistry Reference: {((PP₃)Rh)2(PCHO)}(BPh₄)2(117984-82-4)
• EPA Substance Registry System: {((PP₃)Rh)2(PCHO)}(BPh₄)2(117984-82-4)

Safety Data

• Hazardous Substances Data: 117984-82-4(Hazardous Substances Data)

Upstream product

• 109786-30-3 {(PP₃)RhH} 
• 50777-76-9 (2-formylphenyl)(diphenyl)phosphine 

Relevant articles and documents

Oxidative addition/reductive elimination of aldehydes and ketones at rhodium

The trigonal-bipyramidal, TBP, monohydrides [(NP3)RhH] and [(PP3)RhH] undergo electrophilic attack by MeOSO2CF3 in THF to give CH4 and the 16-electron fragments (NP3)Rh+ and (PP3)Rh+, respectively [NP3 = N(CH2CH2PPh2)3; PP3 = P(CH2CH2PPh2)3]. The (NP3)Rh+ fragment inserts across sp2 C-H bonds of aliphatic and aromatic aldehydes to yield stable Rh(III) cis hydrido acyl complexes of general formula [(NP3)Rh(H)(COR)]+ (R = H, Me, Ph, 4-MeC6H4, 4-MeOC6H4, CH=CHCH=CO, trans-MeCH=CH, trans-PhCH=CH). These can be isolated as tetraphenylborate salts. Under the same conditions, the (PP3)Rh+ fragment is unable either to directly activate aldehydes or to keep hydride (or alkyl) and acyl groups in mutually cis positions of the coordination sphere. As a matter of fact, protonation with HOSO2CF3 or alkylation with ROSO2CF3 (R = Me, Et) of the TBP σ-acyl complexes [(PP3)Rh(COR)] (R = Me, Ph) promotes the reductive elimination of aldehydes or ketones, respectively. Reaction of the (PP3)Rh+ fragment with HCHO in THF results in the decarbonylation of formaldehyde and formation of the TBP carbonyl [(PP3)Rh(CO)]+. Both the NP3Rh and the PP3Rh systems react with acrolein to yield, regardless of the temperature, the η2-alkene derivatives [LRh{η2-CH2=CH(CHO)}]+ (L = NP3, PP3), which exhibit fluxional behavior in solution. When propargylaldehyde, HC≡CCHO, is used, cis hydrido acetylide derivatives of formula [LRh(H)(C≡CCHO)]+ are obtained (L = NP3, PP3), thus indicating that the cleavage of the sp C-H bond prevails over that of the formyl sp2 C-H bond. The (NP3)Rh+ and (PP3)Rh+ fragments react with o-(diphenylphosphino)benzaldehyde, PCHO, yielding cis hydrido acyl complexes, in which a phosphine donor of the tripodal ligands is replaced by the PCHO phosphorus atom.