A highly selective, radical-mediated (4 + 2) coupling reaction of aldehydes and conjugated olefins has been achieved through asymmetric SOMO-catalysis. A radical-polar crossover mechanism is proposed wherein olefin addition to a transient enamine radical cation and oxidation of the resulting radical furnishes a cation which is vulnerable to nucleophilic addition. A range of aromatic aldehydes a...

The mechanism of the proline-catalyzed aldol reaction has stimulated considerable debate, and despite limited experimental data, at least five different mechanisms have been proposed. Complementary to recent theoretical studies we have initiated an experimental program with the goal of clarifying some of the basic mechanistic questions concerning the proline-catalyzed aldol reaction. Here we su...

A one-pot synthesis of various GABA amides has been demostrated, employing the nucleophilic addition of primary and secondary amines across the double bond of cyclopropene-3-carboxamides, followed by ring-opening of the resulting donor-acceptor cyclopropanes and subsequent in situ reduction of enamine (imine) intermediates.

A novel strategy for highly efficient utilization of chiral ammonium salt catalysts has been described in this paper. Three kinds of catalytic functions including iminium catalysis, enamine catalysis, and acid catalysis of chiral ammonium salt catalysts, have been achieved in the enantioselective reduction and alkylation reaction of α,β-unsaturated aldehydes with alcohols.

A simple sensing ensemble was designed to discriminate structurally similar divalent metal chlorides utilizing multivariate data analysis. The system features the binding of four synthesized coumarin-enamine probes to a series of ten metal chlorides. Linear discriminant analysis (LDA) achieves what univariate data analysis alone cannot i.e., full analyte discrimination and differentiation.

The mol-ecule of the title compound, C(22)H(23)N(3)O(3), exists in the enamine-keto form. A strong intra-molecular N-H⋯O hydrogen bond occurs, generating an S(6) ring. The dihedral angle between the heterocycle and the adjacent phenyl ring is 3.75 (15)°.

The mol-ecule of the title compound, C(27)H(24)N(4)O(5), exists in the keto-enamine tautomeric form, stabilized by an intra-molecular N-H⋯O hydrogen bond. An intra-molecular C-H⋯·O hydrogen bond also occurs. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into chains.

Alcoholic beverage consumption is associated with an increased risk of upper gastrointestinal cancer. Acetaldehyde (AA), the first metabolite of ethanol, is a suspected human carcinogen, but the molecular mechanisms underlying AA carcinogenicity are unclear. In this work, we tested the hypothesis that polyamines could facilitate the formation of mutagenic alpha-methyl-gamma-hydroxy-1,N2-propano...

Carbonyls and amines are yin yang in organocatalysis as they mutually activate transform each other. These intrinsically reacting partners tend to condense with other, thus depleting their individual activity when used together cocatalysts. Though widely established many prominent catalytic strategies, aminocatalysis carbonyl catalysis do not coexist well, and, such, a cooperative amine/carbony...

A modular, one-pot, two-step, four-component synthesis of polysubstituted 1,3-oxzolidines is described. The method comprises two linked domino processes: an organocatalyzed domino reaction of alkyl propiolate and an aliphatic aldehydes and a microwave-assisted amine addition cyclization domino process. An alternative modular, one-pot, three-step, four-component synthesis has also been developed...