Carboxylate-Directed Highly Stereoselective Homogeneous Hydrogenation of Cyclic Olefins with Wilkinson's Catalyst

Abstract

A highly efficient diastereoselective, carboxylate-directed homogeneous hydrogenation of cyclic olefins with use of Wilkinson's catalyst is described. Under the optimized reaction conditions, better than 99% de was achieved. The experimental protocol is very simple and readily amenable to scale-up. [reaction: see text]

Experimental and Theoretical Studies of the Potential Interconversion of the Amine–Borane iPr2NH·BH(C6F5)2 and the Aminoborane iPr2N=B(C6F5)2 Involving Hydrogen Loss and Uptake

“…Transition-metal-catalysed olefin hydrogenation is an exceptionally well-developed field within which various metals have now been shown to be effective, [80] with the recent focus mainly on enantioselective hydrogenations. [81,82] With a view to probing the catalytic hydrogenation of 2 we selected representative examples of homo-and heterogeneous rhodium catalysts, Rh(PPh 3 ) 3 Cl (Wilkinson's catalyst), [83] and Rh/Al 2 O 3 , for initial investigation. Catalytic alkene hydrogenation can often be achieved at room temperature under 1 bar or less of H 2 , [83,84] but in our own system, no reaction prevailed using 3 mol-% of either catalyst at 20°C over 24 h under 1 or 100 bar of H 2 according to analysis by 11 B NMR spectroscopy.…”

Synthesis of the mixed acetal segment of S-glyceroplasmalopsychosine

“…The reduction of the internal double bond of 25 was achieved by hydrogenation using Wilkinson’s catalyst21,22 to produce the compound 4 in quantitative yield (Scheme 7). …”

Substituted indanylacetic acids as PPAR-α–γ activators

“…These methods have been detailed in a separate publication. 7 These intermediates could be further substituted as shown in Scheme 2. Bromination of the phenols gave mainly 6-bromo products, with small amounts of the 4,6-dibromo adducts.…”

“…This method along with X-ray crystallographic analysis of a chiral a-methylbenzylamine salt (see footnote 11 in Ref. 7) provided the assignments in Table 6.…”