Rylander

Catalytic hydrogenation is mostly used to convert C—C triple bonds into C C double bonds and alkenes into alkanes or to replace allylic or benzylic hetero atoms by hydrogen (H. Kropf, 1980). Simple theory postulates cis- or syn-addition of hydrogen to the C—C triple or double bond with heterogeneous (R. L. Augustine, 1965, 1968, 1976 P. N. Rylander, 1979) and homogeneous (A. J. Birch, 1976) catalysts. Sulfur functions can be removed with reducing metals, e. g. with Raney nickel (G. R. Pettit, 1962 A). Heteroaromatic systems may be reduced with the aid of ruthenium on carbon. 

Rylander, P. N, 1979, Catalytic Hydrogenation in Organic Syntheses, Academic Press New York London... 

P. N. Rylander, Hydrogenation Methods, Academic Press, Inc., Orlando, Fla., 1985. 

M. Ereifelder, in Catalytic Hydrogenation in Organic Synthesis Procedures and Commentay, ]ohrs Wiley Sons, Inc., New York, 1978, Chapts. 5, 7. P. N. Rylander, Inc., Catalytic Hydrogenation in Organic Syntheses, Academic Press, New York, 1979. 

P. Rylander, Chemical Catalyst News, the Engelhard Corporation, Isebn N.J., Oct. 1989. 

DJERASSI RYLANDER Oxidation Ru04 in oxidative cleavage ot phenols or alkenes oxidation ol aromatics to quinones oxidation ol alkyl amides to irmdes or ol ethers lo esters... 

Catalysis of Organic Reactions, edited by Paul N. Rylander, Harold Greenfield, and Robert L. Augustine... 

P. N. Rylander and X. Vaflor, paper presented at the New York-New England Catalysis Society, Spring Symposium, New Haven, Connecticut, March, 1974. 

Platinum, especially platinum oxide, has been used by many investigators (5), Platinum oxide, when used with aldehydes is apt to be deactivated before reduction is completed. Deactivation is inhibited by small amounts of ferrous or stannous chlorides (59,82). This type of promoter can also sharply curtail hydrogenolysis if it is a troublesome reaction (Rylander and Starrick, 1966). Deactivated systems can often be regenerated by shaking the reaction mixture with air (2,8,21 J3,96). The usefulness of this regenerative technique transcends aldehyde reductions it frequently is worth resorting to. 

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