Molybdenum-Catalyzed Asymmetric Allylic Alkylation Reactions Using Mo(CO)6 as Precatalyst

Advanced Synthesis and Catalysis

Volumn 343, Issue 1, 2001, Pages 46-50

  Palucki, Michael ^a   Um, Joann M ^a   Conlon, David A ^a   Yasuda, Nobuyoshi ^a   Hughes, David L ^a   Mao, Bing ^a   Wang, Jian ^a   Reider, Paul J ^a  

^a MERCK RESEARCH LABORATORIES   (United States)

Author keywords

Allylic alkylation; Asymmetric catalysis; Homogeneous catalysis; Molybdenum; N ligands

Indexed keywords

EID: 0002798209     PISSN: 16154150     EISSN: None     Source Type: Journal    
DOI: 10.1002/1615-4169(20010129)343:1<46::AID-ADSC46>3.0.CO;2-W     Document Type: Article

References (22)

1. (a) G. C. Lloyd-Jones, A. Pflatz, Angew. Chem. Int. Ed. Engl. 1995, 34, 462-464;
2. (b) J. P. Janssen, G. Helmchen, Tetrahedron Lett. 1997, 38, 8025-8026;
3. (c) B. M. Trost, I. Hachiya, J. Am. Chem. Soc. 1998, 120, 1104-1105;
4. (d) P. A. Evans, J. D. Nelson, J. Am. Chem. Soc. 1998, 120, 5581-5582;
5. (e) F. Glorius, A. Pfaltz, Organic Lett. 1999, 1, 141-144.
6. For reviews on asymmetric transition metal-catalyzed allylic alkylations, see (a) B. M. Trost, D. L. Van Vranken, Chem. Rev. 1996, 96, 395-422; (b) T. Hayashi, in: Catalytic Asymmetic Synthesis, (Ed.: I. Ojima), VCH, New York, 1993, pp 325-365.
7. For reviews on asymmetric transition metal-catalyzed allylic alkylations, see (a) B. M. Trost, D. L. Van Vranken, Chem. Rev. 1996, 96, 395-422; (b) T. Hayashi, in: Catalytic Asymmetic Synthesis, (Ed.: I. Ojima), VCH, New York, 1993, pp 325-365.
8. For notable exceptions wherein chiral branched products are obtained as the major isomer using palladium-catalyzed systems, see: (a) T. Hayashi, M. Kawatsura, Y. Uozumi, J. Chem. Soc., Chem. Commun. 1997, 561-562; (b) R. Prétôt, A. Pfaltz, Angew. Chem. Int. Ed. Engl. 1998, 37, 323-325.
9. For notable exceptions wherein chiral branched products are obtained as the major isomer using palladium-catalyzed systems, see: (a) T. Hayashi, M. Kawatsura, Y. Uozumi, J. Chem. Soc., Chem. Commun. 1997, 561-562; (b) R. Prétôt, A. Pfaltz, Angew. Chem. Int. Ed. Engl. 1998, 37, 323-325.
10. B. M. Trost, S. Hildbrand, K. Dogra, J. Am. Chem. Soc. 1999, 121, 10416-10417.
11. The only reported synthesis of ligand 1 yields the desired product in 47% yield from picolinic acid and 1,2-diaminocyclohexane, via activation with triphenyl phosphite. See: D. J. Barnes, R. L. Chapman, R. S. Vagg, E. C. Walton, J. Chem. Eng. Data., 1978, 23, 348-359. We have found that activation of picolinic acid with 1,1-carbodiimidazole is remarkably effective and provides crystalline ligand 1 in 86% isolated yield, D. A. Conlon, N. Yasuda, Adv. Synth. Catal., 2001, 343, 137-138.
12. The only reported synthesis of ligand 1 yields the desired product in 47% yield from picolinic acid and 1,2-diaminocyclohexane, via activation with triphenyl phosphite. See: D. J. Barnes, R. L. Chapman, R. S. Vagg, E. C. Walton, J. Chem. Eng. Data., 1978, 23, 348-359. We have found that activation of picolinic acid with 1,1-carbodiimidazole is remarkably effective and provides crystalline ligand 1 in 86% isolated yield, D. A. Conlon, N. Yasuda, Adv. Synth. Catal., 2001, 343, 137-138.
13. During the course of manuscript review, ligand 1 became commerically available from Strem Chemical Company.
14. G. J. Kubas, L. S. Van Der Sluys, Inorg. Syntheses, 1990, 28, 29-33.
15. th ed, Merck & Co., Inc. Rahway N. J. 1989 item 7839, pp 1244.
16. B. M. Trost, personal communication.
17. 3 see: F. A. Cotton, J. A. McCleverty, J. E. White, Inorg. Syntheses, 1990, 28, 45-47.
18. 6 as precatalyst with ligand 1 appeared. The reaction employs the use of microwave irradiation resulting in internal reaction temperatures of 140-180°C. See: O. Belda, N.-F. Kaiser, U. Bremberg, M. Larhed, A. Hallberg, C. Moberg, J. Org. Chem. 2000, 65, 5868-5870.
19. 6-catalyzed alkylation reaction of carbonate 2 performed in the absence of ligand 1 gave, after 15 h at 90°C, a 42% assay yield of a mixture of regio-isomeric products in a 1.4:1 ratio of branched to linear products. By comparison, alkylations performed using the chiral catalyst are complete within 8-12 h. No alkylation product was observed in the absence of any molybdenum-precatalyst.
20. A waterfall plot of the CO region of the IR spectra from our in situ IR studies is included in the supporting information.
21. 3 as precatalyst in THF.
22. rel = ln[(1 - c)(1-ee)]/ln[(1 - c)(1 + ee)], where ee is the enantiomeric excess of the starting material and c the conversion of the starting material. See: H. B. Kagan, J. C. Fiaud, in: Topics in Stereochemistry Vol 5 (Eds.: N. L. Allinger, E. L. Eliel), Interscience; New York 1987, vol 14, pp 249.