Catalytic Highly Enantioselective Direct Amination of 1,3-Diketones

Abstract

The direct asymmetric amination of 1,3-diketones by azodicarboxylates catalyzed by chiral copper(II) bisoxazolines is presented. Screening of chiral bisoxazoline ligands, Lewis acids, solvents, and other reaction parameters led to an enantioselective direct amination in the 2-position of 1,3-diketones and the optically active functionalized molecules were obtained in high yields and enantioselectivities.

Keywords

asymmetric catalysis - 1,3-diketones - aminations - amines - chiral Lewis acids

References

• For some recent reviews see:
• 1a Modern Amination Methods   Ricci A. Wiley-VCH; Weinheim: 2000. 
• 1b Erdik E. Tetrahedron  2004,  60:  8647 
• 1c Greck C. Drouillat B. Thomassigny C. Eur. J. Org. Chem.  2004,  1377 
• 2a For a recent highlight see: Duthaler RO. Angew. Chem. Int. Ed.  2003,  42:  975 
• 2b See also: Ma J.-A. Angew. Chem. Int. Ed.  2003,  42:  4290 
• 3a Juhl K. Jørgensen KA. J. Am. Chem. Soc.  2002,  124:  2420 
• 3b Marigo M. Juhl K. Jørgensen KA. Angew. Chem. Int. Ed.  2003,  42:  1367 
• 3c Evans DA. Nelson SG. J. Am. Chem. Soc.  1997,  119:  6542 
• 3d Evans DA. Nelson SG. Org. Lett.  1999,  1:  595 
• 3e See also: Yamamoto Y. Yamamoto H. J. Am. Chem. Soc.  2004,  126:  4128 
• 3f Moniyama N. Yamamoto H. J. Am. Chem. Soc.  2004,  126:  5360 
• 4a Bøgevig A. Juhl K. Kumaragurubaran N. Zhuang W. Jørgensen KA. Angew. Chem. Int. Ed.  2002,  41:  1790 
• 4b List B. J. Am. Chem. Soc.  2002,  124:  5656 
• 4c Kumaragurubaran N. Juhl K. Zhuang W. Bøgevig A. Jørgensen KA. J. Am. Chem. Soc.  2002,  124:  6254 
• 4d Vogt H. Vanderheiden S. Bräse S. Chem. Commun.  2003,  2448 
• 5 Hamashima Y. Hotta D. Sodeoka M. J. Am. Chem. Soc.  2002,  124:  11240 
• For metal-catalyzed direct amination reactions leading to racemic products see:
• 6a Fioravanti S. Morreale A. Pellacani L. Tardella PA. Tetrahedron Lett.  2001,  42:  1171 
• 6b Clarine J. Gálvez N. Marchi C. Moreno-Manas M. Vallribera A. Molins E. Tetrahedron  1999,  55:  7331 
• 7 One example of catalytic enantioselective amination of a 1,3-diketone with good enantioselectivity using a chinchona alkaloid as the catalyst is known: Saaby S. Bella M. Jørgensen KA. J. Am. Chem. Soc.  2004,  126:  8120 
• For reviews of C₂-symmetric bisoxazoline-Lewis acid complexes as catalyst see:
• 8a Ghosh AK. Mathivanen P. Cappiello J. Tetrahedron: Asymmetry  1998,  9:  1 
• 8b Jørgensen KA. Johannsen M. Yao S. Audrian H. Thorhauge J. Acc. Chem. Res.  1999,  32:  605 
• 8c Johnson JS. Evans DA. Acc. Chem. Res.  2000,  33:  325 
• 8d Basek R. Synlett  2003,  1223 
• 9 See: Thorhauge J. Roberson M. Hazell RG. Jørgensen KA. Chem.-Eur. J.  2002,  8:  1888 ; and references therein