Efficient catalytic isomerization of allylic alcohols to carbonyl compounds with water soluble rhodium complexes

Hydrogenation and Redox Isomerization of Allylic Alcohols Catalyzed by a New Water-Soluble Pd–tetrahydrosalen Complex

“…Blum and co-workers studied the catalytic properties of ion pairs obtained from PdSO 4 and Aliquat 336 in water and found a maximum TOF = 4.8 h –1 in the redox isomerization of oct-1-en-3-ol at 80 °C . The catalytic activity of the complex obtained from PdSO 4 and sulfonated bis(diphenylphosphino)propane, DPPPS, was characterized by a TOF = 228 h –1 in biphasic isomerization of hex-1-en-3-ol in water/heptene at 50 °C . It was gratifying, therefore, that [Pd(HSS)] catalyzed the hydrogenation/redox isomerization of various allylic alcohols under mild conditions with an overall activity in hydrogenation and redox isomerization of oct-1-en-3-ol up to TOF = 1980 h –1 at 9 bar of H 2 and 80 °C (Table , entry 13).…”

“…35 The catalytic activity of the complex obtained from PdSO 4 and sulfonated bis(diphenylphosphino)propane, DPPPS, was characterized by a TOF = 228 h −1 in biphasic isomerization of hex-1-en-3-ol in water/heptene at 50 °C. 36 It was gratifying, therefore, that [Pd(HSS)] catalyzed the hydrogenation/redox isomerization of various allylic alcohols under mild conditions with an overall activity in hydrogenation and redox isomerization of oct-1-en-3-ol up to TOF = 1980 h −1 at 9 bar of H 2 and 80 °C (Table 2, entry 13). This value exceeds most of the activities of hitherto reported Rh-and Rubased catalysts and is exceptionally high for a palladium complex catalyst.…”

Redox isomerisation of allylic alcohols catalysed by water-soluble ruthenium complexes in aqueous systems

“…The turnover frequencies determined under optimum conditions were generally less than 500 h À1 , with the notable exception of the catalyst prepared in situ from Rh 2 (SO 4 ) 3 and mtpptsNa 3 (TOF = 2520 h À1 in the reaction of oct-1-en-3-ol in THF at 80°C [34]). It should be noted that in the above studies no attempts were made to control the pH of the aqueous solutions (phases), e.g.…”

“…Several water-soluble rhodium(I) complexes were also applied as catalyst in such reactions [33][34][35]. The turnover frequencies determined under optimum conditions were generally less than 500 h À1 , with the notable exception of the catalyst prepared in situ from Rh 2 (SO 4 ) 3 and mtpptsNa 3 (TOF = 2520 h À1 in the reaction of oct-1-en-3-ol in THF at 80°C [34]).…”

Redox Isomerization of Allylic Alcohols Catalyzed by New Water-Soluble Rh(I)-N-Heterocyclic Carbene Complexes

“…Sasson and coworkers observed complete transformation of oct-1-en-3-ol to 3-octanone in benzene/water mixtures with 2% mol RhCl 3 [34]. Biphasic systems with water-soluble rhodium complexes of meta-trisulfonated triphenylphosphine (mtppts) derivatives were reported by de Bellefon [16,35]. Several other rhodium complexes were successfully applied in aqueous media for the redox isomerization of allylic alcohols [18,[36][37][38][39][40], however, no water-soluble Rh(I)-NHC-or Rh(I)-(NHC)-(phosphine) complexes have been reported for this purpose to date.…”