(Bicyclo[2.2.1]hepta‐2,5‐diene)[1,4‐bis(diphenylphosphino)butane]rhodium(I) Tetrafluoroborate

[82499-43-2] C35H36BF4P2Rh (MW 708.4) InChI = 1S/C28H28P2.C7H8.BF4.Rh/c1-5-15-25(16-6-1)29(26-17-7-2-8-18-26)23-13-14-24-30(27-19-9-3-10-20-27)28-21-11-4-12-22-28;1-2-7-4-3-6(1)5-7;2-1(3,4)5;/h1-12,15-22H,13-14,23-24H2;1-4,6-7H,5H2;;/q;;-1;+1 InChIKey = FVKIJNAEINIHMG-UHFFFAOYSA-N (reagent for catalytic hydrogenation;9-11 hydrosilylation,26 hydroboration,27, 28 and aldol condensation32) Physical Data: mp 211–212 °C (dec). Solubility: insol Et2O, pentane; sol CH2Cl2, MeOH, etc. Form Supplied in: orange crystalline powder. Drying: used as supplied in anhydrous solvent. Analysis of Reagent Purity: 31P NMR indicates presence of free phosphine ligand and phosphine oxides; the characteristic 103Rh coupled doublet (JRhP = 155 Hz) demonstrates pure material. Preparative Method: a solution of [Rh(nbd)acac] in THF is treated with fluoroboric acid, followed by addition of 1,4-bis(diphenylphosphino)butane (dppb). The solution becomes deep red and ether is added to precipitate the catalyst, which is then isolated by filtration.3a The unpurified product is generally adequately pure for most applications. Recrystallization from methanol can be performed to obtain orange needles of [Rh(nbd)(dppb)]BF4. Although air-sensitive in solution, the crystalline complex is indefinitely stable when prepared pure and stored under N2 or Ar below 0 °C. A convenient preparation of the corresponding trifluoromethanesulfonate has been described.3b The cyclooctadiene (cod) analog has been characterized by X-ray crystallography,4 and the dynamic solution structure of related systems has been studied by multinuclear NMR techniques.5 Handling, Storage, and Precautions: store under argon in freezer; stable as solid; solutions are air sensitive. Literature describes the use of perchlorate salts but their use cannot be recommended due to risk of detonation. Use in a fume hood.