Asymmetric Organocatalysis and the Nitro Group Functionality

Abstract

The nitro group is an exceptionally versatile functional group, not only because it is essentially a masked amine, but also because its chemistry can be exploited in a number of useful ways. Asymmetric organocatalysis in particular has capitalized on the use of the nitro group towards the synthesis of a variety of nitrogencontaining targets. Perhaps of greatest interest is that this functional group has been shown to be invaluable within the rapidly expanding field of organocatalytic domino reactions. This review features selected examples of nitro group reactivity in organocatalysis to demonstrate its dynamism and utility.

Synthesis of new pyrrolidine-based organocatalysts and study of their use in the asymmetric Michael addition of aldehydes to nitroolefins

“…With this series of pyrrolidines at hand, the well-established Michael addition of aldehydes to nitroolefins [16–18] was selected as a benchmark reaction to study their behaviour as organocatalysts. Compounds with a related structure prepared from proline by Diez et al have proven to work well as organocatalysts in the Michael addition of cyclohexanones to nitrostyrenes [19–20].…”

Prüfverfahren zur Bestimmung des Säurewiderstands von Betonen

“…While proline gave moderate results, multifunctional catalysts Ia–d and IIa–d should allow more distant activating sites, so we expected the transition state to fit better in the tripeptide structure. Among the electrophilic substrates, nitroalkenes are interesting substrates for H‐bonding activation or electrostatic interaction with the phosphonic acid due to the electron‐withdrawing effect of the nitro group 14b…”

Organic Nitrating Reagents

“…7 Improvement in recent years is also related to novel synthetic applications of the nitro group that go beyond classical redox transformations, including, but not limited to, denitrative cross-couplings, 8 radical reactions, 9 and asymmetric organocatalytic transformations. 10…”