We have evaluated the role of achiral pyrazolidinone templates in conjunction with chiral Lewis acids in room temperature, enantioselective Diels-Alder cycloadditions. The role of the fluxional N(1) substituent was examined, with the bulky 1-naphthylmethyl group providing enantioselectivities up to 99% ee, while templates with smaller fluxional groups gave lower selectivities. High selectivitie...

We report on the synthesis and investigation of two diastereomers (5a and 5b) of a new bicalutamide analog with an asymmetric carbon atom and a chiral sulfoxide group. These bicalutamide analogs are novel androgen receptor antagonists with biological activities that depend significantly on the configuration of their stereogenic centers. We determined the absolute configuration at the SO center ...

We prove (in superspace) the equivalence between the higher-derivative N = 1 supergravity, defined by a holomorphic function F of the chiral scalar curvature superfield, and the standard theory of a chiral scalar superfield with a chiral superpotential W , coupled to the (minimal) Poincaré supergravity in four spacetime dimensions. The relation between the holomorphic functions F and W is found...

Hydrosilylation of acetylene with a chiral silane, R-(+)-methyl-1-naphthylphenylsilane [R-(+)-MeNpPhSi*H], in the presence of H2PtCl6·xH2O proceeds with retention of the configuration of the stereogenic silicon center and produces a chiral vinylsilane or silylethylene [S-(+)-MeNpPhSi*Vi] of high optical purity under mild conditions (50°C) in high chemical yield (85%). Anionic polymerizations of...

cis-[Ru(dmp)(2)(CH(3)CN)(2)][PF(6)](2) (dmp = 2,9-dimethyl-1,10-phenanthroline), complex 1[PF(6)](2), exists in two enantiomeric forms, Delta and Lambda. During treatment with the chiral anion tris[tetrachlorobenzene-1,2-bis(olato)]phosphate(V), also named Trisphat, in dichloromethane it has been possible to selectively precipitate each enantiomer, associated with Trisphat in the form of the he...

Our molecules of interest were mainly 2-substituted pyrrolidine and piperidine alkaloids containing 1, 3-aminoketone and 1, 3-aminoalcohol units which are of special synthetic interest (Figure 1). Hygrine and norhygrine belong to the class of tropane alkaloids. The rest of the alkaloids are isolated from 60 species of the genus Sedum and are usually referred as Sedum alkaloids which are of imme...

Analysis of electronic, structural and mechanistic parameters of the enzyme-substrate reaction of xanthine oxidase, a member of the xanthine dehydrogenase class of mono-molybdopterin oxidoreductive enzymes, shows that the molybdenum center in the enzyme active site acts as a reversible chiral switch. The metal center cycles from the (S)-absolute configuration, SPY-5-42-A, in the fully oxidized ...