Complexing properties and chirality of carbohydrates were utilized in diastereoselective reactions of 0-pivaloylated N-galactosylimines with allylsilanes and -stannaries. With dyltrimethylsilane in the presence of SnCh, imines 2 of aromatic and heteroaromatic aldehydes were converted to homdylamines 3, giving ratios of diastereomers higher than 7:l. No addition products derived from a-anomeric ...

The synthesis and characterization of derived imines from 4-imino-5,6,7,8-tetrahydro-1-benzo thieno[2,3-d]pyrimidin-3(4H)-amine 3 has been developed in 3 steps through the reaction of heteroaromatic o-aminonitrile 1 with triethyl orthoformate afforded the corresponding imido ester 2 followed by cyclization with hydrazine hydrate to furnish iminothienopyrimidineamine 3 and finally the imination ...

Propargylamines are important intermediates for the synthesis of polyfunctional amino derivatives and natural products and biologically active compounds. The classic method of synthesizing chiral propargylamines involves the asymmetric alkynylation of imines. Here, we report a significant advance in the catalytic asymmetric Mannich-type synthesis of propargylamines through catalytic asymmetric ...

The annuloselectivity in the reactions of methanesulfonyl sulfene and imines varies with temperature. At a relatively higher temperature of 20 °C, the [2(s) + 2(i)] annulation of different N-alkyl imines occurs exclusively, giving four-membered trans-β-sultams in up to 69% yields. At a lower temperature of -78 °C, the [2(s) + 2(i) + 2(i)] annulation of N-methyl imines takes place specifically, ...

Highly enantio- and diastereoselective organocatalytic Mannich reactions of glycine Schiff bases with N-Boc-protected imines are described. Imines were generated in situ from bench-stable alpha-amido sulfones. Catalysis mediated by a cinchona alkaloid thiourea provided optically active alpha,beta-diamino acid derivatives with up to 99% ee and near-perfect diastereoselection.

Enamines and imines have long been recognized as key intermediates in enzyme catalysis, particularly within a class of enzymes organic chemists would very much like to emulate, the aldolases. Here we summarize the contributions of this laboratory to converting enzymatic enamines, and in some cases imines, into a versatile catalytic asymmetric strategy powered by small organic molecules.

the synthesis and characterization of derived imines from 4-imino-5,6,7,8-tetrahydro-1-benzo thieno[2,3-d]pyrimidin-3(4h)-amine 3 has been developed in 3 steps through the reaction of heteroaromatic o-aminonitrile 1 with triethyl orthoformate afforded the corresponding imido ester 2 followed by cyclization with hydrazine hydrate to furnish iminothienopyrimidineamine 3 and finally the imination ...

Typically, Povarov reactions of imines derived from aromatic amines and aromatic aldehydes show poor exo/endo-stereoselectivity and to date no data is available on the regioselectivity of the cyclisation when 3-substituted imines are employed. We have demonstrated that reaction using acyclic enamides as the alkene component with 3-nitro substituted imines is completely regioselective and gave o...

The stereoselective reduction of imines with trichlorosilane catalyzed by chiral Lewis bases is a well-established procedure for the synthesis of enantio-enriched amines. Five supported cinchona-based picolinamides have been prepared and their activity tested in a model reaction. The comparison of different supporting materials revealed that polystyrene gave better results than silica in terms ...

The ortho-nitro effect was discovered in sulfa-Staudinger cycloadditions of ethoxycarbonylsulfene with linear imines. When an ortho-nitro group is present at the C-aryl substituents of linear imines, the sulfa-Staudinger cycloadditions deliver cis-β-sultams in considerable amounts, together with the predominant trans-β-sultams. In other cases, the above sulfa-Staudinger cycloadditions give rise...