Copper(ii)-mediated resolution of α-halo carboxylic acids with chiral O,O′-dibenzoyltartaric acid: spontaneous racemization and crystallization-induced dynamic resolution

Efficient synthesis of 5-(hydroxymethyl)piperazin-2-ones using automatically prepared chiral bromocarboxylic acid and Garner's aldehyde as versatile building blocks

An efficient method for the synthesis of substituted 5-(hydroxymethyl)piperazin-2-ones was established by using an automated synthesis process. Thirteen piperazinones were synthesized from chiral α-bromocarboxylic acids and Garner's aldehyde which were prepared by using our originally developed automated synthesizer, ChemKonzert®. The automated method of synthesizing chiral α-bromocarboxylic acids was efficient and safe because the rate of the dropwise addition of the reagent can be controlled using the automated synthesizer. This method is expected to contribute to the synthesis of pharmaceuticals.

Preparation of Enantiomerically Enriched P-Stereogenic Dialkyl-Arylphosphine Oxides via Coordination Mediated Optical Resolution

Optical resolution of several dialkyl-arylphosphine oxides was elaborated using the Ca2+ salt of (−)-O,O’-dibenzoyl-(2R,3R)-tartaric acid as the resolving agent. The conditions of crystallization and purification of the enantiomerically enriched phosphine oxides were optimized. Ethyl-phenyl-propylphosphine oxide and butyl-methyl-phenylphosphine oxide were prepared with an enantiomeric excess higher than 93%, whereas, three other dialkyl-arylphosphine oxides were obtained with an enantiomeric excess of 37–85%. It was also found that the sterically demanding alkyl chains hinder the formation of stable diastereomeric complexes, which consequently led to less efficient resolution procedures.

Formation of a novel ferromagnetic end-to-end cyanate bridged homochiral helical copper(ii) Schiff base complex via spontaneous symmetry breaking

A homochiral helical coordination polymer of copper(ii) has been synthesized using achiral precursors. End-to-end cyanate bridges mediate ferromagnetic exchange interactions among copper(ii) centres.