Synthesis of Nitro compounds by 1,4-addition
Me-DuPHOS monoxide is a very effective ligand in the enantioselective copper-catalyzed enantioselective addition of dialkylzinc reagents to β-nitroalkenes offering high yields of nitroalkanes, broad and complementary substrate scope, and high enantioselectivities.
A. Côté, V. N. G. Lindsay, A. B. Charette, Org. Lett., 2007, 9, 85-87.
In an efficient rhodium/olefin-sulfoxide catalyzed asymmetric conjugate addition of organoboronic acids nitroalkenes, 2-methoxy-1-naphthyl sulfinyl functionalized olefin ligands are highly effective and applicable to a broad scope of aryl, alkyl, and heteroaryl nitroalkenes.
F. Xue, D. Wang, X. Li, B. Wan, J. Org. Chem., 2012, 77, 3071-3081.
Enantioselective organocatalytic Michael addition of aldehydes to nitroethylene catalyzed by (S)-diphenylprolinol silyl ether provides β-substituted-δ-nitroalcohols in nearly optically pure form. The Michael adducts bear a single substituent adjacent to the carbonyl and can be efficiently converted to protected γ2-amino acids.
Y. Chi, L. Guo, N. A. Kopf, S. H. Gellman, J. Am. Chem. Soc., 2008, 130, 5048-5049.
Kinetic studies on enamine catalysis provided insight into the rate determining step(s) of conjugate addition reactions between aldehydes and nitroolefins. Not enamine formation but both the reaction of the enamine with the electrophile and hydrolysis of the resulting imine are rate limiting. These results enabled the reduction of the loading of the peptidic catalyst by a factor of 10.
M. Wiesner, G. Upert, G. Angelici, H. Wennemers, J. Am. Chem. Soc., 2010, 132, 6-7.
A simple, practical, and environmentally benign asymmetric Michael addition of aldehydes to nitroolefins on water provided Michael adducts in excellent diastereo- and enantioselectivities in the presence of a water-soluble organocatalyst. The catalyst can be recycled for more than six times without a significant loss of activity and stereochemical control.
Z. Zheng, B. L. Perksin, B. Ni, J. Am. Chem. Soc., 2010, 132, 50-51.
A strategy for the asymmetric Michael addition of aldehydes to nitroolefins with a catalytic system of an organocatalyst in combination with ionic-liquid-supported benzoic acid gives excellent diastereo- and enantioselectivities. A notable feature of this organocatalytic system is that the catalyst can be recycled more than 12 times without significant loss of enantioselectivity.
D. Sarkar, R. Bhattarai, A. D. Headley, B. Ni, Synthesis, 2011, 1993-1997.
The peptide H-D-Pro-Pro-Glu-NH2 is a highly effective catalyst for conjugate addition reactions between aldehydes and nitroethylene to obtain γ-nitroaldehydes and, after reduction, monosubstituted γ-nitroalcohols in excellent yields and optical purities. The products can be readily converted into γ2-amino acids that were previously only accessible by the use of chiral auxiliaries.
M. Wiesner, J. D. Revell, S. Tonazzi, H. Wennemers, J. Am. Chem. Soc., 2008, 130, 5610-5611.
Under the catalysis of a thiophosphoramide derived from 1,2-diphenylethane-1,2-diamine, adducts from the asymmetric Michael addition of acetone to both aromatic and aliphatic nitroolefins were obtained in high yields with excellent enantioselectivities under mild reaction conditions. Moreover, the catalyst could be recovered via simple phase separation and reused at least five times.
A. Lu, T. Liu, R. Wu, Y. Wang, G. Wu, Z. Zhou, J. Fang, C. Tang, J. Org. Chem., 2011, 76, 3872-3879.
A bifunctional organocatalyst efficiently catalyzed not only enantioselective conjugate addition of aromatic ketones to nitroolefins in good yields with excellent enantioselectivities but also enantioselective conjugate addition of acetone to nitroolefins in excellent yields with high enantioselectivities.
Z.-W. Sun, F.-Z. Peng, Z.-Q. Li, L.-W. Zhou, S.-X. Zhang, X. Li, Z.-H. Shao, J. Org. Chem., 2012, 77, 4103-4110.
Copper-catalyzed conjugate addition of dialkylzing reagents to acyclic nitroalkenes using a chiral phosphoramidite ligand gave products in enantioselectivities up to 98%. Routes to (functionalized) 2-amino aldehydes, acids, and alcohols are described.
A. Duursma, A. J. Minnaard, B. L. Feringa, J. Am. Chem. Soc., 2003, 125, 3700-3701.
An efficient and highly enantioselective conjugate addition of alkylzinc reagents to various cyclic nitroalkenes is promoted in the presence of 0.5-5 mol % (CuOTf)2·C6H6 and 1-10 mol % of chiral amino acid-based phosphine ligands at 0°C in toluene. Depending on the reaction conditions used, either the nitro or the corresponding α-substituted ketone product can be accessed.
C. A. Luchaco-Cullis, A. H. Hoveyda, J. Am. Chem. Soc., 2002, 124, 8192-8193.
A simple organocatalyst provided access to Michael adducts of the addition of nitroalkenes to aldehydes with very high diastereo- and enantioselectivity and a broad range of β-substitution patterns. Almost equimolar amounts of the aldehyde donor can be employed.
C. Palomo, S. Vera, A. Mielgo, E. Gómez-Bengoa, Angew. Chem. Int. Ed., 2006, 45, 5984-5987.
Pyrrolidine-based chiral ionic liquids are highly efficient organocatalysts for Michael additions of a broad range of michael donors (both ketones and aldehydes) to nitroolefins with high yields, excellent enantioselectivities, and very good diastereoselectivities. The ionic liquid moiety not only acts as a tag to facilitate recycling but functions also as an efficient chiral-induction group.
S. Luo, X. Mi, L. Zhang, S. Liu, H. Xu, J.-P. Cheng, Angew. Chem. Int. Ed., 2006, 45, 3093-3097.
A fluorous (S)-pyrrolidine sulfonamide organocatalyst promotes highly enantio- and diastereoselective Michael addition reactions of ketones and aldehydes with nitroolefins in water. The organocatalyst is conveniently recovered from the reaction mixtures by fluorous solid-phase extraction and can be reused.
L. Zu, J. Wang, H. Li, W. Wang, Org. Lett., 2006, 8, 3077-3079.