The development of efficient protocols for the palladium-catalyzed cyclization reactions of secondary amides and carbamates

Organic Letters

Volumn 1, Issue 1, 1999, Pages 35-37

  Yang, Bryant H ^a   Buchwald, Stephen L ^a  

^a MASSACHUSETTS INSTITUTE OF TECHNOLOGY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

AMIDE; CARBAMIC ACID DERIVATIVE; CHELATING AGENT; LIGAND; PALLADIUM;

ARTICLE; CATALYSIS; CHEMISTRY; CYCLIZATION;

AMIDES; CARBAMATES; CATALYSIS; CHELATING AGENTS; CYCLIZATION; LIGANDS; PALLADIUM;

EID: 0033564994     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol9905351     Document Type: Article

References (13)

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2. (a) Wolfe, J. P.; Wagaw, S.; Marcoux, J.-F.; Buchwald, S. L. Acc. Chem. Res. 1998, 31, 805.
3. (b) Yang, B. H.; Buchwald, S. L. J. Organomet. Chem. 1999, 576, 121.
4. Hartwig, J. F. Angew. Chem., Int. Ed. Engl. 1998, 37, 2090.
5. (a) Wolfe, J. P.; Wagaw, S.; Buchwald, S. L. J. Am. Chem. Soc. 1996, 118, 7215.
6. (b) Sadighi, J. P.; Harris, M. C.; Buchwald, S. L. Tetrahedron Lett. 1998, 39, 5327.
7. Optically active MOP, (±)-BINAP, and DPEphos (vide infra) are commercially available from Strem Chemical Co. (±)-MOP is prepared from a literature procedure. See: (a) Uozumi, Y.; Hayashi, T. J. Am. Chem. Soc. 1991, 113, 9887.
8. (b) Kurz, L.; Lee, G.; Morgans, D. Jr.; Waldyke, M. J.; Ward, T. Tetrahedron Lett. 1990, 31, 6321.
9. Prepared using the procedures described in ref 1. In each case, the crude primary amine precursor was prepared by lithium aluminum hydride reduction of the corresponding nitrile. Small amounts (2-7%) of debromination can also occur during the reduction step. Substrates 1-4 are therefore contaminated with small amounts of the corresponding debrominated material. The denominated byproduct is not believed to affect the efficiency of the cyclization step, and it is easily removed by flash column chromatography after the cyclization step.
10. Kranenburg, M.; van der Burgt, Y. E. M.; Kamer, P. C. J.; van Leeuwan, P. W. N. M.; Goubitz, K.; Fraanje, J. Organometallics 1995, 14, 3081.
11. He, F.; Foxman, B. M.; Snider, B. B. J. Am. Chem. Soc. 1998, 120, 6417.
12. 2: C, 72.07; H, 8.21. Found: C, 72.15; H, 8.33.
13. Kranenburg, M.; Delis, J. G. P.; Kamer, P. C. J.; van Leeuwen, P. W. N. M.; Vrieze, K.; Veldman, N.; Spek, A. L.; Goubitz, K.; Fraanje, J. J. Chem. Soc., Dalton Trans. 1997, 1839.