Bicarbonate Salts as Cost-Effective Bases for the Synthesis of Ketenes and Their Synthetic Equivalents Applied to the Asymmetric Synthesis of β-Lactams

Abstract

We report the use of bicarbonate salts as viable alternative­s to more expensive bases for the in situ generation of ketenes and their synthetic equivalents. We have successfully applied­ this to the catalytic, asymmetric synthesis of β-lactams.

Key words

β-lactam - bicarbonate salts - asymmetric catalysis - cinchona­ alkaloids

References

• 1a Tidwell TT. Ketenes   John Wiley & Sons; New York: 1995. 
• 1b Tidwell TT. Acc. Chem. Res.  1990,  23:  273 
• 2a Palomo C. Aizpurua JM. Ganboa I. Oiarbide M. Eur. J. Org. Chem.  1999,  3223 
• 2b Lynch JE. Riseman SM. Laswell WL. Tschaen DM. Volante RP. Smith GB. Shinkai I. J. Org. Chem.  1989,  54:  3792 
• 3 Hegedus has found that trialkylammonium salts can interfere with the diastereoselectivity of the Staudinger reaction to produce β-lactams: Hegedus LS. Montgomery J. Narukawa Y. Snustad DC. J. Am. Chem. Soc.  1991,  113:  5784 
• 4 Taggi AE. Hafez AM. Wack H. Young B. Drury WJ. Lectka T. J. Am. Chem. Soc.  2000,  122:  7831 
• 5 Hafez AM. Taggi AE. Wack H. Esterbrook J. Lectka T. Org. Lett.  2001,  3:  2049 
• 6 Taggi AE. Wack H. Hafez AM. France S. Lectka T. Org. Lett.  2002,  4:  627 
• 7a Hafez AM. Taggi AE. Lectka T. Chem.-Eur. J.  2002,  8:  4114 
• 7b Hafez AM. Taggi AE. Dudding T. Lectka T. J. Am. Chem. Soc.  2001,  123:  10853 
• 7c Wack H. Taggi AE. Hafez AM. Drury WJ. Lectka T. J. Am. Chem. Soc.  2001,  123:  1531 
• 7d Hafez AM. Taggi AE. Wack H. Drury WJ. Lectka T. Org. Lett.  2000,  2:  3963 
• 8a Taggi AE. Hafez AM. Wack H. Young B. Ferraris D. Lectka T. J. Am. Chem. Soc.  2002,  124:  6626 
• 8b Taggi AE. Hafez AM. Lectka T. Acc. Chem. Res.  2003,  36:  10 
• 8c France S. Wack H. Hafez AM. Taggi AE. Witsil DR. Lectka T. Org. Lett.  2002,  4:  627 
• 8d Dudding T. Hafez AM. Taggi AE. Wagerle TR. Lectka T. Org. Lett.  2002,  4:  387 
• 8e Hafez AM. Dudding T. Wagerle TR. Shah MH. Taggi AE. Lectka T. J. Org. Chem.  2003,  68:  5819