Catalysis in Organic Syntheses 1977 PDF
Preview Catalysis in Organic Syntheses 1977
Catalysis in Organic Syntheses 1977 EDITED BY Gerard V. Smith Department of Chemistry and Biochemistry Southern Illinois University. Carbondale, Illinois ACADEMIC PRESS, INC. New York San Francisco London 1977 A Subsidiary of Harcourt Brace Jovanovich, Publishers Academic Press Rapid Manuscript Reproduction Copyright © 1977, by Academic Press, Inc. ALL RIGHTS RESERVED. NO PART OF THIS PUBLICATION MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM OR BY ANY MEANS, ELECTRONIC OR MECHANICAL, INCLUDING PHOTOCOPY, RECORDING, OR ANY INFORMATION STORAGE AND RETRIEVAL SYSTEM, WITHOUT PERMISSION IN WRITING FROM THE PUBLISHER. ACADEMIC PRESS, INC. Ill Fifth Avenue, New York, New York 10003 United Kingdom Edition published by ACADEMIC PRESS, INC. (LONDON) LTD. 24/28 Oval Road. London NW1 Library of Congress Cataloging in Publication Data Conference on Catalysis in Organic Syntheses, 6th, Boston, 1976. Catalysis in organic syntheses 1977. Includes indexes. 1. Catalysis—Congresses. 2. Chemistry, Organic—Synthesis—Congresses. I. Smith, Gerard V. II. Title. QD505.C66 1976 547'.2 77-20217 ISBN 0-12-650550-0 PRINTED IN THE UNITED STATES OF AMERICA List of Contributors Numbers in parentheses indicate the pages on which the authors' contributions begin. John C. Bailar, Jr. (1), University of Illinois, Champaign, Illinois 61801 Dennis J. Baker (1), University of Illinois, Champaign, Illinois 61801 F. Behbahany (95), National Iranian Oil Company, Tehran, Iran Carl H. Brubaker, Jr. (25), Michigan State University, East Lansing, Michigan 48824 Alan J. Chalk (139), Givaudan Corporation, Clifton, New Jersey 07014 M. Djalali (95), National Iranian Oil Company, Tehran, Iran G. A. Doldouras (189), Merck, Sharp & Dohne Research Laboratories, Rahway, New Jersey 07065 T. R. Engelmann (175), Southern Illinois University, Carbondale, Illinois 62901 R. Fellows(175), Southern Illinois University, Carbondale, Illinois 62901 Nissim Garti (9), University of Arkansas, Fayetteville, Arkansas 72701 D. Grote (165), Ashland Chemical Research & Development, Dublin, Ohio 43216 Laurence L. Ho (197), Southern Illinois University, Carbondale, Illinois 62901 L. Jennings (175), Southern Illinois University, Carbondale, Illinois 62901 W. H. Jones (189), Merck, Sharp & Dohne Research Laboratories, Rah way, New Jersey 07065 George W. Keulks (109), University of Wisconsin, Milwaukee, Mil waukee, Wisconsin 53201 Vera M. Kolb (197), Southern Illinois University, Carbondale, Illinois 62901 J. Kollonitsch (189), Merck, Sharp & Dohne Research Laboratories, Rahway, New Jersey 07065 Steven A. Magennis (139), Givaudan Corporation, Clifton, New Jersey 07014 V vi LIST OF CONTRIBUTORS T. Mason (165), Ashland Chemical Research & Development, Dublin, Ohio 43216 Walters. Matthews (197), Southern Illinois University, Carbondale, Il linois 62901 Cal Y. Meyers (197), Southern Illinois University, Carbondale, Illinois 62901 William S. Millman (33), Southern Illinois University, Carbondale, Il linois 62901 M. Moronski (175), Southern Illinois University, Carbondale, Illinois 62901 Thomas E. Parady (197), Southern Illinois University, Carbondale, Il linois 62901 Randall Partridge (153), Mobil Research Corporation, Paulsboro, New Jersey T. J. Pinnavaia (131), Michigan State University, East Lansing, Michigan 48824 Steven L. Regen (119), Marquette University, Milwaukee, Wisconsin 53233 S. Salajegheh (95), National Iranian Oil Company, Tehran, Iran Vladislav A. Seleznev (153), Institute of Chemical Physics, Moscow, USSR Z. Sheikhrezai (95), National Iranian Oil Company, Tehran, Iran Samuel Siegel (9), University of Arkansas, Fayetteville, Arkansas 72701 D. W. Slocum (175), Southern Illinois University, Carbondale, Illinois 62901 Gerard V. Smith (33), Southern Illinois University, Carbondale, Illinois 62901 B. Trivedi (165), Ashland Chemical Research & Development, Dublin, Ohio 43216 P. B. Venuto (67), Mobil Research & Development Corporation, Prince ton, New Jersey 08540 Alvin H. Weiss (153), Worcester Polytechnic Institute, Worcester, Mas sachusetts 01609 Preface Catalysis in Organic Syntheses 1977 is the result of the Sixth Confer ence on Catalysis in Organic Syntheses held by the Organic Reactions Catalysis Society in Boston on May 10 and 11, 1976. Because the Fifth Conference was held one year later than usual and because the Society wished to stagger its biennial meeting with that of The Catalysis Soci ety, only one year lapsed between the Fifth and Sixth Conferences. Consequently the timing was such that several manuscripts were com pleted in 1977. This collection of papers offers the organic chemist a glimpse at some novel catalytic systems as well as an update on more traditional sys tems. Starting with hydrogenation, a broad range of topics is covered. Both homogeneous and heterogeneous aspects of catalysis are ad dressed and, in addition to the more standard papers, two compre hensive reviews are included. Besides the individual authors and editor, others contributed in im portant ways to a successful meeting and the resulting book. Thanks are due to the session chairmen Paul N. Rylander, Gerald M. Jaffe, and Robert L. Augustine who did the real work of running the symposium. Harold Greenfield efficiently handled certain technical arrangements and chaired the Organic Reactions Catalysis Society business meeting. William Jones, as secretary-treasurer of the Society, superbly handled the finances, registration, and many other details. It is a pleasure to express thanks to Engelhard Industries, Intertec Associates, Parr Instrument Co., Autoclave Engineers, W. R. Grace and Co., Parke- Davis, and Matthey- Bishop for their support of the Sixth Conference. Shirley Huff, with her excellent typing skills, put together and pro duced the typed manuscript. Special thanks are due to Cynthia Kiriakos who not only put together the author index and made out the subject index cards, but also contributed in general ways to the finished man uscript. vii HETEROGENEOUS SELECTIVE CATALYSIS OF THE HYDROGENATION OF ENEYNES BY POLYMERIC PALLADIUM (II) COMPLEXES Dennis J. Baker and John C. Bailar, Jr. Department of Chemistry, University of Illinois Urbana, IL 61801 Palladium complexes of polymeric diphenylbenzylphosphine ligands are employed as catalysts for the heterogeneous selective hydrogenation of l-en-3-ynes to monoenes. The com plete product distribution was obtained for the l-hepten-3-yne reaction. Certain modes of hydrogen addition are found to be consistent with this distribution. The work which is reported here began with attempts to hydrogenate soybean methyl ester selectively in order to eliminate the linolenic ester which is present to the extent of about 9% and which imparts a bitter taste to the oil. Ideally, one would hydrogenate only the double bonds in the 15-position, without affecting the ethylenic bonds at the 9- and 12-positions. This would convert the linolenate to linoleate, which is the main component of soybean oil (about 50%) and which has a good flavor and is easily digested. The other components of the oil are oleate (27%), stearate (4%) and palmitate (10%). It is important that no hydrogenation to sterate take place, for stearate esters are not readily digested. Attempts to hydrogenate soybean oil selectively have been made by earlier workers, for it is a subject of importance to the food industry (12). Our early work was done with homogeneous catalysts and has been adequately reviewed ( ) . 2 These reviews also cover some work which was done on short chain polyunsaturated hydrocarbons. Later work on hydro carbons was described by Itatani and Bailar (7). The homogeneous catalysis which has been mentioned, utilized [Pt(Ρφ ) 012] + SnCl2r though it was found quite 3 2 possible to replace the platinum by palladium or nickel, the phosphorus by arsenic, antimony, sulfur or selenium, the phenyl groups by other aryl or alkyl or ester groups, and the chloride by bromide, iodide, cyanide, or other pseudo-halide 1 2 D. J. BAKER AND J. C. BAILAR, JR. groups. The tin can be replaced by lead or germanium, though these are not as effective as tin. If the chloride is re placed by iodide or cyanide, the addition of tin halide is not necessary (2a). The work with homogeneous catalysts led to the following conclusions: 1. In general, long chain polyunsaturates can be hydrogenated readily to the monoene stage with very little reduction to saturation. 2. The double bonds are free to migrate along the chain and, under mild reaction conditions, it is possible to isomerize the substrate without hydrogenation. 3. Double bonds which are not hydrogenated are con verted largely, though not exclusively, to the trans form. 4. In short chain olefins, at least, terminal double bonds tend to be hydrogenated, even if no other double bonds are present in the molecule. Ethylene is reduced rapidly, but the rate of hydrogenation falls off as the length of the chain is increased. 5. Short chain diolefins tend to isomerize to the conjugated form, which attaches itself to the catalyst so tightly that the latter becomes ineffective, Thus, the addition of a little 1,3-butadiene to ,5-hexadiene completely 1 blocks isomerization and reduction of the hexadiene (!). . The use of non-coordinating solvents (e.g., 6 CH CI or CHCI ) allows the hydrogenation reaction to proceed 2 2 3 several times as fast as it does in coordinating solvents such as methanol (10). After a good deal of work had been done with the homo genous catalyst, it was decided to "heterogenize" it by attaching it to polystyrene crossed linked with divinyl benzene: -/CH ---CH----/cHo--------------- CH----V- 0 r\ ) I v 1 \ CH2Cl/n \ ΟΗ2Ρφ2 / n Vch --CH----V- 2 0 / / ch 2 ?Φ 2 \ M-complex / n HETEROGENEOUS SELECTIVE CATALYSIS 3 At this time, the resulting catalyst has been studied only to a limited extent, but it has been shown that, under proper conditions, it will hydrogenate triene to diene, with very little reduction to monoene or saturated hydrocarbon (4). When "M complex" represents ^[-PtC^] in the heterogeneous catalyst, tin (II) chloride must be added to give good catalytic effect, but if the platinum is replaced by the more active palladium, this is not necessary (4). In the work reported here, the reduction of l-hepten-3- yne and l-octen-3-yne to monoenes has been studied. The catalytic hydrogenation of alkynes has been reported by Candlin and Oldham (5), by Osborn and his students (9) and by Crabtree ( ), all of whom used rhodium complexes as homo 6 geneous catalysts. We have used only heterogeneous catalysts, of the type described above for the hydrogenation of olefins. Utilizing a combination of gas chromatography and pmr, the complete isomeric distribution of heptenes was determined in the case of the 1-hepten-3-yne reduction. In addition to the five heptenes, two heptadienes and one heptyne were isolated and identified. I. EXPERIMENTAL SECTION A. Materials Analytical grade chemicals and solvents were used with out further purification except in the case of tetrahydrofuran which was dried by refluxing over lithium aluminum hydride. The purity of the hydrocarbon substrates and of the solvents used in the hydrogenation experiments was checked by gas chromatographic analysis prior to use. The eneynes, l-hepten-3-yne, and l-octen-3-yne, were obtained from Farchan Division, Story Chemical Corporation. Dichlorobis (benzonitrile) palladium (II) was prepared according to the method of Kharasch, Seyler and Mayo (8). Chloromethylated Amberlite XAD-4 was a gift of the Rohm and Haas Company and has been described earlier (4b). A sample of chloromethylated Bio-Beads S-X2 was obtained as 200-400 mesh spheres from Bio-Rad Laboratories. Diphenylphosphine was prepared by the lithium-induced cleavage of triphenylphosphine according to the method of Wittenberg and Gilman (II). B. Polymeric Phosphines Two phosphine-polymer preparations were employed in this study. The ligand designated as P2 was derived from the 4 D. J. BAKER AND J. C. BAILAR, JR. chloromethylated Amberlite XAD-4 (4b). The polymeric phosphine designated as P4 was obtained via a modified procedure which will be described in another place (3). C. Palladium-Phosphine Complexes The complex derived from P2 is designated by its empiri cal formula P2· (PdC^)0.824· Its preparation was described previously (4b). The polymeric palladium complex, P -(PdCl )o was prepared from P4 and dichlorobis 4 2 888 (benzonitriie) palladium (II) by an analogous procedure. The hydrogenations were carried out at atmospheric pressure; the procedures have been described (4). II. RESULTS AND DISCUSSION A. Hydrogenation of 1-Hepten-3-yne After 130 minutes at room temperature and one atmosphere of hydrogen pressure with mg of P *(PdCl )o 824 catalyst, 20 2 2 a sample of l-hepten-3-yne ( ml) in methanol ml) was 1.0 (20 reduced to a mixture consisting of 50% original eneyne, 36% heptenes, 9% 1,3-heptadienes, 5% 3-heptyne, and a trace (< 2%) of 2,3-heptadiene. Approximately 95% of the eneyne had reacted after 280 minutes. Figure 1 illustrates that the heptadiene concentration started to decrease as the eneyne concentration dropped below 10%. It was only at this penultimate stage in the reaction that any (^ %) heptane was 1 detected. The complete product distribution from the reduction of l-hepten-3-yne was determined through a combination of gas chromatographic and pmr analysis. The product mixtures from three reductions were combined and the heptene fraction isolated via preparative glpc on the TCEP column. This mixture was then analyzed by pmr spectroscopy to give a tentative estimate of the relative amounts of 1-, 2-, and 3- heptenes. Gas chromatography on a silver nitrate column was used to separate the alkenes into two fractions. The peak at lower retention time ( % of the mixture) contained the two 22 trans isomers while the peak at long retention time con sisted of cis-2-, cis-3-, and 1-heptene. Results of the pmr analysis of both of these fractions combined with data from the total mixture and the glpc integrations are summarized in Table I. It should be emphasized that this is the product distribution at high eneyne conversion (80% or greater) and may not be valid at earlier stages in the reaction* HETEROGENEOUS SELECTIVE CATALYSIS 5 -----Γ 1 1 1 1 1 1 1 1 100 z 80 1- heptene -3-yne 1 i 60 ^ \ l ./''^heptenes o a* _j 40 o Έ ^ 20 ^ (heptadieneT^CK^^ π D l 3 4 5 2 TIME (hours) Fig. 1. The catalytic hydrogenation of 1-hepten-3-yne in methanol (with P2·(PdCl2)o.824)· TABLE 1 Isomeric Composition of the Heptene Products from the Hydrogenation of 1-Hepten-3-yne in Methanol at Atmospheric Pressure Composition of Olefin the Heptene Fraction 1-Heptene 25% cis-2-Heptene 11% cis-3-Heptene 42% trans-2-Heptene 18% trans-3-Heptene 4% Hydrogenation of 1-hepten-3-yne with P4·(PdCl ) 2 0.888 under the same conditions as outlined above resulted in a
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