Expedient synthesis of substituted imidazoles from nitriles

Expedient and practical new methodology for the synthesis of substituted imidazoles was developed to provide a rapid access to a variety of 2-substituted, 1,2-disubstituted and 1,2,4-trisubstituted imidazoles by the direct CuCl-mediated reaction of nitriles with α-amino acetals in an intermolecular as well as intramolecular fashion.     

A practical synthesis of 2-(N-substituted)-aminobenzimidazoles utilizing CuCl-promoted intramolecular cyclization of N-(2-aminoaryl)thioureas

A practical protocol for synthesis of 2-(N-substituted)-aminobenzimidazoles was developed. N-(2-Aminoaryl)thioureas undergo a CuCl-promoted intramolecular cyclization to give the corresponding 2-(N-substituted amino)benzimidazoles in good to excellent isolated yields.     

Addition of grignard reagents to aryl acid chlorides: an efficient synthesis of aryl ketones

[chemical reaction: see text]. Direct addition of Grignard reagents to acid chlorides in the presence of bis[2-(N,N-dimethylamino)ethyl] ether proceeds selectively to provide aryl ketones in high yields. A possible tridentate interaction between Grignard reagents and bis[2-(N,N-dimethylamino)ethyl] ether moderates the reactivity of Grignard reagents, preventing the newly formed ketones from nucleophilic addition by Grignard reagents.     

A new and practical boronic acid catalyzed intramolecular cyclodehydration of ureas for the synthesis of LFA-1 antagonists

A streamlined and practical approach to 1H-imidazo[1,2-α]imidazol-2-one LFA-1 antagonist (1) that features as the key step a novel intramolecular boronic acid catalyzed cyclocondensation of a urea and an amide is reported.     

Carbohydrates as Multifunctional Chiral Scaffolds in Combinatorial Synthesis

Four orthogonally stable protecting groups and a selectively cleavable anchor that are stable under basic conditions are required in order that carbohydrates can be employed as chiral polyfunctional scaffolds in combinatorial solid-phase syntheses of high diversity. The schematic representation shows the combinatorial synthesis with a carbohydrate scaffold (SG=protecting group, A=anchor, P=polymer carrier), which proceeds by sequential selective deprotection, functionalization, washing of the solid phase, and cleavage of the anchor.     

Properly designed modular asymmetric synthesis for enantiopure sulfinamide auxiliaries from N-sulfonyl-1,2,3-oxathiazolidine-2-oxide agents

Simple and practical asymmetric synthesis of functionally differentiated aminoindanol based endo-N-sulfonyl 1,2,3-oxathiazolidine-2-oxide as sulfinyl transfer agents are developed. The importance of these new and unique sulfinyl transfer reagents are exemplified by the expedient production of several sulfinamide ligands, including either enantiomer of (R)-tert-butanesulfinamide in excellent yields and enantiopurities.     

Palladium catalyzed alkoxy- and aminocarbonylation of vinyl tosylates

The palladium catalyzed alkoxycarbonylation and aminocarbonylation of vinyl tosylates are described. A variety of ketone and aldehyde derived vinyl tosylates may be carbonylated in the presence of primary, secondary, and tertiary alcohols, or primary and secondary amines, to provide the corresponding esters and amides in good yields. The alkoxycarbonylation was applied to a short synthesis of isoguvacine.