Non-racemic Diastereoselective Synthesis of gamma-lactams via Michael Addition of 1,3-dicarbonyl Compounds to Chiral Nitroalkenes.

Non-racemic Diastereoselective Synthesis of gamma-lactams via Michael Addition of 1,3-dicarbonyl Compounds to Chiral Nitroalkenes.

Vieira, Daniel Pais Pires; Vieira, Bruna Gil Nicolay; Pereira, Vera Lúcia Patrocinio

Abstract:

Nitroalkenes are one of the most versatile intermediates in organic synthesis. Since they are electrondeficient alkenes participle of a huge number of reactions of carbon-carbon and carbonheteroatom bond formation with varied nucleophiles in Michael addition, Baylis-Hillman and Friedel- Crafts reactions beyond cycloadditions ([3+2] and [4+2]). Stereoselective synthesis using natural aminoacids as chiral pool is very attractive since they are low cost and versatile starting materials. Michael Addition of 1,3-dicarbonyl compounds to nitroalkenes is one very studied reaction. Nowadays, the enantioselective version to this reaction is widely accomplished via organocatalysis approach. A few examples via chiral pool were found in literature. The chiral nitroalkenes (1a-c) were synthesized by first time for us from natural L-aminoacids (2a-c) in 5 steps with an global average yield of 93-97%. Giving pursuit to our strategy of synthesizing new chirons and chiral bioactive substances via aliphatic nitroalkanes we relate here the conjugate addition of methyl malonate to nitroalkene 1a and the transformation in corresponding γ-lactam in high d.e. and yield.

Nitroalkenes are one of the most versatile intermediates in organic synthesis. Since they are electrondeficient alkenes participle of a huge number of reactions of carbon-carbon and carbonheteroatom bond formation with varied nucleophiles in Michael addition, Baylis-Hillman and Friedel- Crafts reactions beyond cycloadditions ([3+2] and [4+2]). Stereoselective synthesis using natural aminoacids as chiral pool is very attractive since they are low cost and versatile starting materials. Michael Addition of 1,3-dicarbonyl compounds to nitroalkenes is one very studied reaction. Nowadays, the enantioselective version to this reaction is widely accomplished via organocatalysis approach. A few examples via chiral pool were found in literature. The chiral nitroalkenes (1a-c) were synthesized by first time for us from natural L-aminoacids (2a-c) in 5 steps with an global average yield of 93-97%. Giving pursuit to our strategy of synthesizing new chirons and chiral bioactive substances via aliphatic nitroalkanes we relate here the conjugate addition of methyl malonate to nitroalkene 1a and the transformation in corresponding γ-lactam in high d.e. and yield.

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DOI: 10.5151/chempro-14bmos-R0138-1

Referências bibliográficas

• [1] 1 Ono, N. The Nitro Group in Organic Synthesis 2001, Eds., VCH, Wiley, New York, USA.
• [2] 2 a) Moura, A. L. S., PhD thesis, NPPN-UFRJ, Rio de Janeiro, 2007. Vieira, D. P. P. R.; Master thesis NPPN-UFRJ, Rio de Janeiro, 2007. Jr-Barreto, C. B. Pereira, V.L.P.Tetrahedron Lett. 2009,42,2456.

Como citar:

Vieira, Daniel Pais Pires; Vieira, Bruna Gil Nicolay; Pereira, Vera Lúcia Patrocinio; "Non-racemic Diastereoselective Synthesis of gamma-lactams via Michael Addition of 1,3-dicarbonyl Compounds to Chiral Nitroalkenes.", p-138-138. In: In Blucher Chemistry Proceedings, São Paulo, v. 1, n. 1, Setembro.2013. São Paulo: Blucher, 2013.
ISSN 23184043, DOI 10.5151/chempro-14bmos-R0138-1