John O. Link

A new chiral catalyst for the enantioselective synthesis of secondary alcohols and deuterated primary alcohols by carbonyl reduction

Abstract An efficient synthesis of (S) -(−)-2-(di-β-naphthylhydroxymethyl)pyrrolidine ( 1 ) makes available the oxazaborolidine derivatives 2 and 3 which are excellent catalysts for borane reduction of a variety of achiral ketones to chiral secondary alcohols, e.g. acetophenone, 98% ee; α-tetralone, 95% ee; and methyl-4-oxo-4-phenyl butyrate, 96% ee. The synthesis of chiral 1-deuterio primary alcohols from achiral aldehydes with B- n -butyloxazaborolidine ( 4 ) as catalyst in the presence of 2 H-catecholborane as reductant has also been demonstrated, e.g. benzaldehyde, 95% ee; cyclohexanecarboxaldehyde, 92% ee; and n -octanal, 90% ee.

A new process for the enantioselective synthesis of chiral α-aryloxy- and α-hydroxy acids

Chiral trichloromethyl carbinols 3, readily available by catalytic enantioselective reduction of trichloromethyl ketones, are converted with inversion of configuration into chiral α-aryloxy and α-hydroxy carboxylic acid derivatives.

Two effective procedures for the synthesis of trichloromethyl ketones, useful precursors of chiral α-amino and α-hydroxy acids

Abstract Trichloroacetic acid can been converted to trichloromethyl ketones in good yield by two practical new procedures, one involving the catalyzed reaction of trichloroacetic acid with aldehydes at 23 °C followed by oxidation and the other utilizing the coupling of organozinc intermediates with trichloroacetyl chloride

A mechanistic and structural analysis of the basis for high enantioselectivity in the oxazaborolidine-catalyzed reduction of trihalomethyl ketones by catecholborane

Abstract The rates and enantioselectivities of the reduction of a series of trihalomethyl ketones under catalysis by oxazaborolidine 2 can be explained in terms of structural and mechanistic analyses which are detailed herein and which have predictive value.

The first enantioselective syntheses of pure R- and S-isoproterenol

Abstract An efficient and highly selective synthetic route to either R - or S -isoproterenol ( 1 ) is described which employs a robot-like catalytic molecule to establish chirality, and readily provides these important therapeutic agents in enantiomerically pure form.

A new process for the generation of 1,3,2-oxazaborolidines, catalysts for enantioselective synthesis

Abstract A simple and easily reproducible procedure for the formation of 1,3,2- oxazaborolidines from β-amino alcohols and bis(trifluoroethyl) alkylboronates, is reported along with a new synthesis of the latter.

General preparation of 3-alkyl-1-naphthols

Potassium enolates derived from readily available o-alkynylacetophenones undergo intramolecular cycloaromatization on heating to afford 3-alkyl-1-naphthols in good yields.

X-ray diffraction studies of crystalline trihalomethyl ketones (RCOCX3) reveal an unusual structural deformation about the carbonyl group

Abstract X-ray crystallographic studies of a set of trihalomethyl ketones ( 4, 5 , and 6 ) indicate that the carbonyl oxygen is displaced significantly toward the trihalomethyl group, probably as a consequence of oxygen lone pair delocalization into the σ* orbital of COX 3 .