A simple method for the removal of phenolic hydroxy-groups

Hydrogenation and hydrogenolysis in synthetic organic chemistry

“…+ I ++ + + palladium gave mainly trans-l,2-dimethylcyclohexane, whilst with platinum as the catalyst the cis-isomer was obtained 47 • Hydrogenation of 1,2-dimethylcyclopentene revealed a somewhat different pattern: Raney nickel gave preferently cis-l,2-dimethylcyclopentane, whereas palladium and platinum gave about 70% of the trans-isomer 48 • A similar problem is encountered in the hydrogenation of 4-t-butylmethylenecyclohexane for example. Chernisorption or coordination of the exocyclic double bond is for steric reasons expected to occur mainly from the equatorial direction (the t-butyl group acts as a 'holding group'), with formation of cis-4-t-butyl-l-methylcyclohexane (methyl group axial).…”

Reduction of aryl diethyl phosphates with titanium metal: a method for deoxygenation of phenols

“…Recrystallization from etherpentane gave 0.400 g (98%) of estradiol 3-(diethyl phosphate): mp 112.5-114.0 °C [lit.12d mp 113.5-115.5 °C]; IR (CHC13) 3600, 3400 (OH), 1600 (aromatic), 1270, 1035, 960 cm"1 (PO(OR)3); NMR (CDC13) 6 0.80 (s, 3 H, CH3), 2.50-1.20 (m, 21 H, -CH2-and CH3CH20), 2.81 (m, 3 H. benzylic), 3.42 (s, 1 H, OH), 3.71 (m, 1 H, CHOH), 4.10 (m, 4 H, CH3CH20), 7.05 (m, 4 H, aromatic). This aryl phosphate ester was then reduced with freshly prepared, highly activated titanium metal as in the above procedure for 18 h to afford 0.215 g (85.6%) of estra-l,3,5(10)-triene-17d-ol: mp 115-117 °C [lit.12d mp 117-118.5 °C]; IR (CHC13) 3600,3460 (OH), 900 cm-1 (aromatic); NMR (CDCI3) 0.79 (s, 3 H, CH3), 2.50-1.15 (m, 15 H, -CH2-), 2.80 (m, 3 H, benzylic), 3.60 (m, 1 H,OH), 3.65 (m, 1 H, CHOH), 7.00 (m, 4 H, aromatic).…”

Reductive Deoxygenation of Alcohols: Catalytic Methods Beyond Barton–McCombie Deoxygenation

“…[21] Nickel(0) has d 10 configuration, which is often found to be highly active in catalysis, and similar to palladium, it is used as a catalyst for C-C bond-coupling reactions. [23] Later, the use of Raney nickel as a catalyst for the transfer hydrogenation of aryl and vinyl perfluoroalkyl sulfonates was compared with palladium and PtO 2 catalysts, and a very high potential for deoxygenation by using this catalyst was found. [23] Later, the use of Raney nickel as a catalyst for the transfer hydrogenation of aryl and vinyl perfluoroalkyl sulfonates was compared with palladium and PtO 2 catalysts, and a very high potential for deoxygenation by using this catalyst was found.…”