Two types of enantioselective [2 + 2 + 2] cycloadditions of triynes using chiral rhodium catalysts are disclosed. The intramolecular reaction of ortho-aminophenol-tethered triynes provides chiral tripodal compounds. Consecutive interand intramolecular reactions of ortho-phenylene-tethered triynes provide chiral tetraphenylenes.

an efficient one-pot three-component procedure for the synthesis of new chiral spiro-oxindolopyrrolizidines with highly regio-, diastereo-, and enantioselective from 1,3-dipolar cycloaddition of azomethine ylides and optically pure active cinamoyl oxazolidinone are described. the process occurs at room temperature in aqueous ethanol as green solvent and in the absence of any bidentate chelating...

The enantioseparation of eighteen new chiral hydantoin derivatives was studied on three different polysaccharide type chiral stationary phases (CSP) Chiralpak AD, Chiralcel OD and Chiralcel OJ in the normal-phase HPLC mode. Chiralpak AD material exhibited the most universal chiral resolving ability and allowed the enantioseparation of 17 out of 18 compounds followed by Chiralcel OD (10 enantios...

The production of enantiopure chiral compounds is important for pharmaceutical and agrochemical industries because enantiomers can exhibit distinct biological activities. Therefore, processes that directly produce the desired enantiomer are desirable. First reported by Knowles, Horner et al. in 1968, catalytic asymmetric hydrogenation of unsaturated compounds such as olefins, ketones, and imine...

Chiral molecules with axial or planar chirality are of special interest to synthetic chemists because of both their unique chirality without stereogenic centers and their practical use as chiral auxiliaries or chiral ligands for catalytic asymmetric syntheses. There are therefore a number of reports on the asymmetric synthesis of these chiral molecules. Unlike common chiral molecules with stere...

Abstract: Many compounds occur in Nature in both enantiomeric forms. This chiral chemodiversity is common among certain classes of natural products whereas other classes of compounds usually occur in only one of the enantiomeric forms. Thus triterpenoids and steroids belong to the same enantiomeric family. On the other hand, many of the lower terpenoids (monosesqui-, and diterpenoids) are prese...

Helical structures are chiral, which means that if we can synthesize a polymer having a stable one-handed helicity, the polymer is optically active. In 1979, we succeeded in the synthesis of a one-handed helical polymer from an optically inactive achiral monomer, triphenylmethyl methacrylate (TrMA). This is the first example of the asymmetric synthesis of an optically active one-handed helical ...

In this study, 6-azido-2,3-di(p-chlorophenylcarbamoylated) cellulose was synthesized and bonded onto aminized silica gel to obtain a new chiral stationary phase. Enantioselectivity of the chiral stationary phase and Chiralcel OF suggested promising chiral separation ability of the new cellulose chiral stationary phase. In addition, the effect of trifluoroacetic acid, diethylamine on enantiosele...

Interesting and unexpected results on the cyanation of prochiral aldehydes catalyzed by chiral copper complexes of R-(+)/(S)-(-) α-ethylphenyl amine (I/II) in anhydrous methanol are presented. The cyanation reaction with chiral copper complexes of R-(+)/S-(-) α-ethylphenyl amines, acetols in methanol perform to afford a series of chiral products such as amines and acetonitriles (compounds 4-6, ...

In the original version of this Article, Affiliation 2 was omitted for Qinghua Zhang. In addition, there were typographical errors. In the Results section under subheading 'Chromatographic separation' " The peak resolution factors (R s) of these chiral compounds were generally high than 1 except for PCB-174 and-83 " now reads: " The peak resolution factors (R s) of these chiral compounds were g...