An Efficient, Eco-friendly and Sustainable One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Directly from Alcohols Catalyzed by Heteropolyanion-Based Ionic Liquids.

Efficient, eco-friendly and sustainable access to 3,4-dihydropyrimidin-2(1H)-ones directly from alcohols under microwave and solvent-free conditions has been reported. The practical protocol involves heteropolyanion-based catalyzed oxidation of alcohols to aldehydes with NaNO3 as the oxidant followed by cyclocondensation with dicarbonyl compounds and urea or thiourea in a two-step, one-pot manner. Compatibility with different functional groups, good to excellent yields and reusable catalysts are the main highlights. The utilization of alcohols instead of aldehydes is a valid and green alternative to the classical Biginelli reaction.

Direct oxidative amidation of aldehydes with amines catalyzed by heteropolyanion-based ionic liquids under solvent-free conditions via a dual-catalysis process.

A simple and efficient procedure for the synthesis of amides directly from aldehydes and amines catalyzed by heteropolyanion-based ionic liquids under solvent-free conditions has been reported. The practical protocol was found to tolerate a wide range of substrates with different functional groups. Moderate to excellent yields, solvent-free media, and operational simplicity are the main highlights. The proposed dual-catalysis mechanistic pathway was briefly investigated. Furthermore, the heteropolyanion-based ionic liquids were easily reusable for this oxidative amidation.

Copper catalyzed C-O bond formation via oxidative cross-coupling reaction of aldehydes and ethers.

A practical and efficient construction of C-O bonds via oxidative cross-coupling reaction of aldehydes and ethers has been realized under open air. When 2 mol% copper was used as the catalyst, various α-acyloxy ethers were obtained with up to 93% isolated yield.

Synthesis of (+)-CP-99,994 via Pd(0)-catalyzed asymmetric allylic and homoallylic C-H Diamination of terminal olefin.

This paper describes an asymmetric synthesis of the potent substance P receptor antagonist (+)-CP-99,994 from 4-phenyl-1-butene via Pd(0)-catalyzed asymmetric allylic and homoallylic C-H diamination.

Rapid access to pyrimido[5,4-c]isoquinolines via a sulfur monoxide extrusion reaction.

The scope of a sulfur monoxide extrusion reaction of pyrimido[4,5-b][1,4]benzothiazepines leading to pyrimido[5,4-c]isoquinolines was investigated. Thus, selective oxidation followed by nucleophilic displacement of the oxidized side chain sulfur group and subsequent extrusion reaction of sulfur monoxide in the ring, which can be conducted in a two-step sequence or in a one-pot procedure, produced novel pyrimido[5,4-c]isoquinolines, a class of compounds with potential biological and pharmaceutical applications. [reaction: see text].

Ezetimibe analogs with a reorganized azetidinone ring: Design, synthesis, and evaluation of cholesterol absorption inhibitions.

The underlying principle of drug design in this paper is that the maximum retention of the functional groups that exist in the marketed drug would provide a higher probability for comparable safety while the conformational changes in the newly created analogs should not constitute a significant structural variation to adversely affect biological activity. Four individual isomers of backbone re-organized ezetimibe analogs were designed and synthesized. Their effects on the cholesterol levels in rat serum were evaluated by a high-cholesterol and high-fat diet feeding experiment. All the new analogs showed significant effect in lowering the levels of total cholesterol in serum.

Synthesis of novel tricyclic pyrimido[4,5-b][1,4]benzothiazepines via Bischler-Napieralski-type reactions.

[reaction: see text] Novel tricyclic pyrimido[4,5-b][1,4]benzothiazepines were readily prepared from 5-amino-4,6-bis(arylthio)pyrimidines and carboxylic acids via Bischler-Napieralski-type reactions. The 6-aryl sulfide group of the resulting pyrimido[4,5-b][1,4]benzothiazepines could be selectively oxidized to its corresponding sulfoxide, which underwent facile substitution reactions when treated with nucleophiles such as an amine. This synthetic strategy provides an efficient way to access a library of novel heterocyclic compounds that are of interest in drug discovery.