Palladium-catalysed three component synthesis of α,β-unsaturated amidines and imidates

Tetrahedron Letters

Volumn 45, Issue 38, 2004, Pages 6991-6994

  Tetala, K Kishore R ^a   Whitby, Richard J ^a   Light, Mark E ^a   Hurtshouse, Michael B ^a  

^a UNIVERSITY OF SOUTHAMPTON   (United Kingdom)

Author keywords

Amidine; Imidate; Isonitrile; Multi component; Palladium catalysed

Indexed keywords

AMIDINE; AMINE; BROMINE DERIVATIVE; ISONITRILE DERIVATIVE; OXIDE; PALLADIUM;

ARTICLE; CATALYSIS; CHEMICAL MODIFICATION; NUCLEAR MAGNETIC RESONANCE; X RAY CRYSTALLOGRAPHY;

EID: 4444383109     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2004.07.150     Document Type: Article

References (18)

1. C.G. Saluste, R.J. Whitby, and M. Furber Angew. Chem., Int. Ed. 39 2000 4156 4158
2. C.G. Saluste, R.J. Whitby, and M. Furber Tetrahedron Lett. 42 2001 6191 6194
3. A. Schoenberg, I. Bartoletti, and R.F. Heck J. Org. Chem. 39 1974 3318 3326
4. A. Schoenberg, and R.F. Heck J. Org. Chem. 39 1974 3327 3331
5. Obtained from the commercial 85:15 E:Z mixture by removal of the latter by treatment with NaOH under phase transfer conditions: M. Makosza, and A.A. Chesnokov Tetrahedron 58 2002 7295 7301
6. Crystallographic data (excluding structure factors) for 1a has been deposited with the Cambridge Crystallographic Data Centre as supplementary publication number CCDC 243515. Copies of the data may be obtained, free of charge, on application to CCDC, 12 Union Road, Cambridge, CB2 1EZ, U.K. (fax: +44(0)-1223-336033 or e-mail: deposit@ccdc.cam.ac.uk)
7. Stereochemistry of arylamidines was erroneously drawn as (Z) in Ref. 1. We later showed it to be (E) on the basis of low temperature NMR studies and calculations (Whitby, R. J., unpublished work)
8. C.L. Perrin S. Patai Z. Rappoport The Chemistry of Amidines and Imidates 1991 Wiley 150
9. 2 is 109 kJ/mol. M. Naulet, M.L. Filleux, G.J. Martin, and J. Pornet Org. Magn. Reson. 7 1975 326 330 and, by analogy with the facile E/Z isomerisation of N-tert-butylimidates (Refs. 7,14), the barrier for amidines 1 would be expected to be lower
10. The low barrier to Ca-N rotation of 1a comes from energetically favourable overlap of the CC and CN bonds in the transition state B, which is not possible in the ground state A
11. Saluste, C. G. PhD Thesis, University of Southampton, 2002
12. 15 to be 40 kJ/mol more stable than (Z)-3a
13. R.J. Whitby, C.G. Saluste, and M. Furber Org. Biomol. Chem. 2 2004 1974 1976
14. 2 is known. F. Ozawa, H. Soyama, T. Yamamoto, and A. Yamamoto Tetrahedron Lett. 23 1982 3383 3386
15. T. Kobayashi, and M. Tanaka J. Organomet. Chem. 233 1982 C64 C66
16. Double carbonylation of aryl iodides to afford α-keto- esters is also known. F. Ozawa, N. Kawasaki, H. Okamoto, T. Yamamoto, and A. Yamamoto Organometallics 6 1987 1640 1651
17. D.E. Gallis, and D.R. Crist Magn. Reson. Chem. 25 1987 480 483
18. DFT calculations were carried out using the hybrid HF-DFT B3LYP method and 6-31G* basis set as implemented in the Spartan04 program (Wavefunction Inc.): J. Kong, C.A. White, A.I. Krylov, D. Sherrill, R.D. Adamson, T.R. Furlani, M.S. Lee, A.M. Lee, S.R. Gwaltney, T.R. Adams, C. Ochsenfeld, A.T.B. Gilbert, G.S. Kedziora, V.A. Rassolov, D.R. Maurice, N. Nair, Y.H. Shao, N.A. Besley, P.E. Maslen, J.P. Dombroski, H. Daschel, W.M. Zhang, P.P. Korambath, J. Baker, E.F.C. Byrd, T. Van Voorhis, M. Oumi, S. Hirata, C.P. Hsu, N. Ishikawa, J. Florian, A. Warshel, B.G. Johnson, P.M.W. Gill, M. Head-Gordon, and J.A. Pople J. Comput. Chem. 21 2000 1532 1548