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The reaction of o-xylylene complexes of ruthenium with alkynes under oxidative conditions
Polyhedron Vol. 5, No. 4.p~. Printed in Great Britain
0277-5387186 Pergamon
1035~1036,1986
s3.00+.00 Journals Ltd
COMMUNICATION THE REACTION OF o_XYLYLENE COMPLEXES OF RUTHENIUM WITH ALKYNES UNDER OXIDATIVE CONDITIONS CHRISTINE
L. SKERRA’IT, S. DAVID CHAPtiELL, RICHARD D. BOWEN, RICHARD C. STORR and DAVID J. COLE-HAMILTON*?
School of Chemistry, University of Liverpool, P.O. Box 147, Liverpool L69 3BX, U.K. (Received 23 September 1985; accepted 25 November 1985)
Abstract-Oxidation of o-xylylene complexes of ruthenium in the presence of dimethyl(acetylenedicarboxylate) produces the dimethylesters of 1,4-dihydronaphthalene2,3-dicarboxylic acid and naphthalene-2,3-dicarboxylic acid.
o-Quinodimethanes are important intermediates in a large number of organic transformations, including the synthesis of pharmacologically active compounds such as steroids.‘*’ Although a number of efficient routes to these reactive species has been developed, the precursors tend not to be readily accessible and a new, direct route from a cheap starting material is therefore highly desirable. In recent years, o-quinodimethane (xylylene) complexes of a number of different metals have been synthesized by a variety of routes.3-g However, no successful attempts to liberate o-quinodimethane from the metal under mild conditions have been reported. Thus, o-quinodimethane was not removed from [C,H,Fe(CO),] by oxidation,3 although, on thermolysis, benzocyclobutane was formed and reaction with AlCl, gave benzocyclopentanone.”
* Author to whomcorrespondence shouldbeaddressed. t Present address : Department of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, U.K. $ The compounds were characterized by comparison of GLC, GLC-mass spectrometry and ‘H NMR spectra, the last on a mixture of the two compounds obtained by column chromatography, with authentic 1 and the literature 1 and 2.”
The only trapping of an o-quinodimethane liberated from a metal complex involves the binuclear [{CpCo(CO)},C,H,], from which the bridging xylylidene ligand was displaced with phosphines and intercepted by dienophiles or else dimerized.” We now report the first indication that oquinodimethanes can be liberated from ruthenium complexes {[C,H,RuP,] (P = PMe,Ph or PMePh,)) by oxidation. Treatment of these complexes in- CH&l, in the presence of dimethyl(acetylenedicarboxylate) @MAD) with an excess of aqueous cerium(IV) ammonium nitrate affords the dihydronaphthalene (1) and naphthalene (2) in yields of 14 and 2%, respectively (P = PMePh,).$ The other major products are the phosphine oxide and the bibenzyl (3). With the less reactive dienophile Me--CC-CO,Me, no adduct was detected and the amount of 3 increased. No reaction occurred between the complex and acetylene in the absence of oxidant and the simplest explanation is therefore that free o-quinodimethane is produced. The yields of 1 and 2 have yet to be optimized by choice of oxidant and reaction conditions. However, the fact that [CsHsRuP,] can be prepared directly from o-xylene’ (Scheme 1) gives the procedure great potential as a route to o-quinodimethane-derived products.
1035
1036
a
(8
CH,
0
CH,
-
a
Communication CH3Li*TMEDA
0
-
(ii)
CH3
(iii)
/
1
3
2
Scheme 1. Synthesis of naphthalene derivatives from o-xylene : (i) BuLi, TMEDA, hexane, 25°C ; (ii) RuCl,P, or [Ru2Cl~Ps]+C!l-, diethylether, 25°C; (iii) excess Ce4+, MeOOCC~COOMe, CH,Cl,-H,O, 25°C.
Acknowledgements-We thank the SERC for support (S.D.C.) and for a grant to purchase a high-field NMR spectrometer, and Johnson Matthey Ltd for loans of ruthenium salts. D.J.C.-H. is the Sir Edward Frankland Fellow of the Royal Society of Chemistry, 1984-1985.
6. 7. 8.
REFERENCES 1. W. Oppoltzer, Synthesis 1978,793. 2. T. Kametani, Pure Appl. Chem. 1979,51,747. 3. W. R. Roth and J. D. Meir, Tetrahedron Lett. 1967, 2053. 4. J. D. Oliver, Ph.D. thesis, Austin, Texas (1971) (Chem. Abstr. 1972, 106413). 5. S. D. Chappell, D. J. Cole-Hamilton, A. M. R. Galas
9.
10.
11. 12.
and M. B. Hursthouse, J. Chem. Sot., Dalton Trans. 1982,1867. M. A. Bennett, I. J. McMahon and T. W. Turney, Angew. Chem., Int. Ed. Engl. 1982,21,379. W. H. Hersh, F. J. Hollander and R. G. Bergman, J. Am. Chem. Sot. 1983,105,5834. J. W. Hull and W. L. Gladfelter, Organometallics 1983, 1, 1716. M. F. Lappert, C. L. Raston,G. L. Rowbottom, B. W. Skelton and A. H. White, J. Chem. Sot., Dalton Trans. 1984,399. B. F. G. Johnson, J. Lewis and D. J. Thompson, Tetrehedron L&t. 1974,3789. W. H. Hersh and R. G. Bergman, J. Am. Cbem. Sot. 1983,105,5846. D. N. Butler and R. A. Snow, Can. J. Chem. 1975,53, 256.
0277-5387186 Pergamon
1035~1036,1986
s3.00+.00 Journals Ltd
COMMUNICATION THE REACTION OF o_XYLYLENE COMPLEXES OF RUTHENIUM WITH ALKYNES UNDER OXIDATIVE CONDITIONS CHRISTINE
L. SKERRA’IT, S. DAVID CHAPtiELL, RICHARD D. BOWEN, RICHARD C. STORR and DAVID J. COLE-HAMILTON*?
School of Chemistry, University of Liverpool, P.O. Box 147, Liverpool L69 3BX, U.K. (Received 23 September 1985; accepted 25 November 1985)
Abstract-Oxidation of o-xylylene complexes of ruthenium in the presence of dimethyl(acetylenedicarboxylate) produces the dimethylesters of 1,4-dihydronaphthalene2,3-dicarboxylic acid and naphthalene-2,3-dicarboxylic acid.
o-Quinodimethanes are important intermediates in a large number of organic transformations, including the synthesis of pharmacologically active compounds such as steroids.‘*’ Although a number of efficient routes to these reactive species has been developed, the precursors tend not to be readily accessible and a new, direct route from a cheap starting material is therefore highly desirable. In recent years, o-quinodimethane (xylylene) complexes of a number of different metals have been synthesized by a variety of routes.3-g However, no successful attempts to liberate o-quinodimethane from the metal under mild conditions have been reported. Thus, o-quinodimethane was not removed from [C,H,Fe(CO),] by oxidation,3 although, on thermolysis, benzocyclobutane was formed and reaction with AlCl, gave benzocyclopentanone.”
* Author to whomcorrespondence shouldbeaddressed. t Present address : Department of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, U.K. $ The compounds were characterized by comparison of GLC, GLC-mass spectrometry and ‘H NMR spectra, the last on a mixture of the two compounds obtained by column chromatography, with authentic 1 and the literature 1 and 2.”
The only trapping of an o-quinodimethane liberated from a metal complex involves the binuclear [{CpCo(CO)},C,H,], from which the bridging xylylidene ligand was displaced with phosphines and intercepted by dienophiles or else dimerized.” We now report the first indication that oquinodimethanes can be liberated from ruthenium complexes {[C,H,RuP,] (P = PMe,Ph or PMePh,)) by oxidation. Treatment of these complexes in- CH&l, in the presence of dimethyl(acetylenedicarboxylate) @MAD) with an excess of aqueous cerium(IV) ammonium nitrate affords the dihydronaphthalene (1) and naphthalene (2) in yields of 14 and 2%, respectively (P = PMePh,).$ The other major products are the phosphine oxide and the bibenzyl (3). With the less reactive dienophile Me--CC-CO,Me, no adduct was detected and the amount of 3 increased. No reaction occurred between the complex and acetylene in the absence of oxidant and the simplest explanation is therefore that free o-quinodimethane is produced. The yields of 1 and 2 have yet to be optimized by choice of oxidant and reaction conditions. However, the fact that [CsHsRuP,] can be prepared directly from o-xylene’ (Scheme 1) gives the procedure great potential as a route to o-quinodimethane-derived products.
1035
1036
a
(8
CH,
0
CH,
-
a
Communication CH3Li*TMEDA
0
-
(ii)
CH3
(iii)
/
1
3
2
Scheme 1. Synthesis of naphthalene derivatives from o-xylene : (i) BuLi, TMEDA, hexane, 25°C ; (ii) RuCl,P, or [Ru2Cl~Ps]+C!l-, diethylether, 25°C; (iii) excess Ce4+, MeOOCC~COOMe, CH,Cl,-H,O, 25°C.
Acknowledgements-We thank the SERC for support (S.D.C.) and for a grant to purchase a high-field NMR spectrometer, and Johnson Matthey Ltd for loans of ruthenium salts. D.J.C.-H. is the Sir Edward Frankland Fellow of the Royal Society of Chemistry, 1984-1985.
6. 7. 8.
REFERENCES 1. W. Oppoltzer, Synthesis 1978,793. 2. T. Kametani, Pure Appl. Chem. 1979,51,747. 3. W. R. Roth and J. D. Meir, Tetrahedron Lett. 1967, 2053. 4. J. D. Oliver, Ph.D. thesis, Austin, Texas (1971) (Chem. Abstr. 1972, 106413). 5. S. D. Chappell, D. J. Cole-Hamilton, A. M. R. Galas
9.
10.
11. 12.
and M. B. Hursthouse, J. Chem. Sot., Dalton Trans. 1982,1867. M. A. Bennett, I. J. McMahon and T. W. Turney, Angew. Chem., Int. Ed. Engl. 1982,21,379. W. H. Hersh, F. J. Hollander and R. G. Bergman, J. Am. Chem. Sot. 1983,105,5834. J. W. Hull and W. L. Gladfelter, Organometallics 1983, 1, 1716. M. F. Lappert, C. L. Raston,G. L. Rowbottom, B. W. Skelton and A. H. White, J. Chem. Sot., Dalton Trans. 1984,399. B. F. G. Johnson, J. Lewis and D. J. Thompson, Tetrehedron L&t. 1974,3789. W. H. Hersh and R. G. Bergman, J. Am. Cbem. Sot. 1983,105,5846. D. N. Butler and R. A. Snow, Can. J. Chem. 1975,53, 256.