ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

No abstract

Racemic 2′-methoxy-1,1′-binaphthyl-2-carboxylic acid was separated on a multi-gram scale into its antipodes via silica-gel column chromatography followed by alkaline hydrolysis of the diastereomeric esters prepared from (R)-1-phenylethanol or (−)-menthol. The molecular structure of (−)-menthyl (aS)-2′-methoxy-1,1′-binaphthyl-2-carboxylate was determined by single-crystal X-ray analysis. The (aS)-acid was converted to crystalline acid chloride, which was conveniently utilized as efficient chiral derivatizing agent for differentiation of enantiomeric alcohols and amines by high-performance liquid chromatography on silica gel. The elution behavior of a pair of diastereomeric esters or amides was explained by the steric interactions between the solutes and the silica-gel stationary phase on the basis of the X-ray analysis.

Grignard reagents formed from 1-bromonaphthalenes smoothly displaced the 1-methoxyl group of 1-methoxy-2-naphthoic esters to provide a facile route to 1,1′-binaphthyl-2-carboxylic acids in excellent yields; the reaction of (S)-1-phenylethyl esters caused asymmetric induction in the joining of the two naphthalene rings in up to 51% optical yield.

Effects of n-type dopants Si and Se on band-gap energy (E g) and on sublattice ordering for Ga0.5In0.5P grown by metalorganic vapor phase epitaxy, under conditions in which E g shows anomalously low E g values if the doping is not carried out, were studied by means of photoluminescence and transmission electron microscopy. In contrast to the previously reported p-type doping case, the effects on E g were interpreted by considering two factors: (i) impurity-doping-induced diorsdering of <1/2, 1/2, 1/2 > superlattice (SL), and (ii) Burstein shift.