Chemoselective Deprotection of Allylic Amines Catalyzed by Grubbs’ Carbene

Abstract

A commercially available ruthenium complex (first generation Grubbs’ carbene) was used for the catalytic deprotection of allylic amines (secondary as well as tertiary), by using for the first time reagents different from palladium catalysts. Interestingly, the catalytic system directs the reaction toward the selective deprotection of allylamines in the presence of allylic ethers.

amines - carbenes - catalytic cleavage - protecting groups - ruthenium

References

1a Greene TW. Wuts GM. In Protective Groups in Organic Synthesis   3rd. ed.:  Wiley; New York: 1999. 

1b Kocienski PJ. Protecting Groups   3rd ed.:  Thieme; Stuttgart: 2003. 

2 For an Ir-catalyzed deprotection of allylamides, see: Neugnot B. Cintrat J.-C. Rousseau B. Tetrahedron  2004,  60:  3575 

3 For a review, see: Guibé F. Tetrahedron  1998,  54:  2967 

4a Review: Alcaide B. Almendros P. Chem. Eur. J.  2003,  9:  1258 

4b See also: Schmidt B. Angew. Chem. Int. Ed.  2003,  42:  4996 

4c See also: Schmidt B. Eur. J. Org. Chem.  2004,  1865 

4d For a recent paper, see: Hong SH. Day MW. Grubbs RH. J. Am. Chem. Soc.  2004,  126:  7414 

5 Schwab P. Grubbs RH. Ziller JW. J. Am. Chem. Soc.  1996,  118:  100 

6a Alcaide B. Almendros P. Alonso JM. Aly MF. Org. Lett.  2001,  3:  3781 

6b Alcaide B. Almendros P. Alonso JM. Chem. Eur. J.  2003,  9:  5793