W. S. Hamama, M. Hammouda*, and E. M. Afsah Chemistry Department, Faculty of Science, Mansoura University, Mansoura, Egypt Z. Naturforsch. 43b, 483-486 (1988); received August 18, 1986/October 26, 1987 Mannich Bases of Enaminones, Octahydro-9H-pyrimido[5,4-b]-azepines, Tetrahydro-4H-[3,l]benzoxazin-5(6H)-one, Nitrogen Heterocycles Mannich reaction of the title compound 1 with morpholine, piperi...

Sulfonated polystyrene/montmorillonite nanocomposite (OMMT/PS-SO3H) was prepared and used as a novel, efficient and inexpensive heterogeneous acid catalyst in the one-pot reaction three-component Mannich reaction of ketones, aromatic aldehydes and amines under solvent-free conditions. The catalyst was characterized by XRD, SEM, TG, BET and FT-IR techniques. This method has advantages...

An efficient synthesis of highly functionalized chiral β-amino ester derivatives containing benzothiophene and benzothiazole moieties is developed by a Mannich-type reaction using a cinchona alkaloid-derived thiourea catalyst. The desired products were obtained in good yields and high enantioselectivities (~86% yield, >99% ee) using to the optimized reaction conditions. The synthesized compound...

A copper-catalyzed synthesis of 2-(aminomethyl)indole through domino three-component coupling-cyclization has been developed. This reaction proceeds through Mannich-type coupling of 2-ethynylanilines, aldehydes, and secondary amines, followed by hydroamination. This indole formation was applicable to the synthesis of 4-methylene-2,3,4,9-tetrahyro-1H-pyrido[3,4-b]indoles and 5,6,7,8-tetrahydrobe...

Catalytic asymmetric Mannich-type reactions of an alpha-hydrazono ester with silicon enolates in aqueous media have been developed by using ZnF2 and chiral diamines as catalysts. In these reactions, both Zn2+ and a fluoride anion were necessary to achieve high yields and enantioselectivities, suggesting a double activation mechanism, in which Zn2+ activates the alpha-hydrazono ester and the flu...

[reaction: see text] Organocatalytic asymmetric Mannich reaction of protected amino ketones with imines in the presence of an L-proline-derived tetrazole catalyst afforded diamines with excellent yields and enantioselectivities of up to 99%. The amino ketone protecting group controlled the regioselectivity of the reaction providing access to chiral 1,2-diamines from azido ketones and 1,4-diamin...

sulfonated polystyrene/montmorillonite nanocomposite (ommt/ps-so3h) was prepared and used as a novel, efficient and inexpensive heterogeneous acid catalyst in the one-pot reaction three-component mannich reaction of ketones, aromatic aldehydes and amines under solvent-free conditions. the catalyst was characterized by xrd, sem, tg, bet and ft-ir techniques. this method has advantages of high yi...

The first decarboxylative Mannich reaction employing β-keto acids, catalyzed by cinchonine-derived bifunctional thiourea catalyst has been described. The desired β-amino ketones were obtained in excellent yields and with moderate to good enantioselectivities.

The substituted tricyclic pyrano[2,3-e]isoindolin-3-ones and , as the core structure of stachybotrin A, B, and C (), have been regioselectively synthesized for the first time by a short route which involved Mannich reaction and Claisen rearrangement.

The reaction o f 1-hydroxyxanthenone (1) and hydroxyquinoline (10, 13) Mannich bases with the reactive phosphacumulated ylides (2), represents a new way for the synthesis o f the pyranones and pyranthiones (5, 11, 14). On the other hand, the stabilized phosphorus ylides (6) affect the transylidation o f the Mannich base (1) to the corresponding phosphoranylidenes (9). The structure o f the resu...