Coordination‐Mediated Optical Resolution of Carboxylic Acids with O, O′‐Dibenzoyltartaric Acid

Abstract

Chiral recognition in the coordination sphere of a calcium ion that is coordinated to a simple tartaric acid derivative offers new possibilities for the preparative‐scale resolution of nonbasic compounds. An example of a mixed calcium salt formed upon resolution of racemic carboxylic acids is shown on the right.

Chiral Polymers of Intrinsic Microporosity: Selective Membrane Permeation of Enantiomers

“…[1] Chromatographic methods, particularly gas-liquid and solid-liquid chromatography,have been the standard analytical approach for enantiomer separation. However,m ost current resolution methods have some limitations.F or example,diastereomeric crystallization often requires the resolution of reagents that are effective only for as pecific system; [3,4] enzyme-mediated kinetic resolution faces decreased catalytic activity over time; [5,6] and chromatographic methods present the disadvantage of being discontinuous and expensive.Although the development of simulated moving bed chromatography (SMB) and supercritical-fluid chromatography (SFC) allows for continuous operation on ap reparative scale, [7][8][9][10] specialized equipment, optimization studies for each substrate,a nd the cost of stationary phases detracts somewhat from the broad application of these methods. However,m ost current resolution methods have some limitations.F or example,diastereomeric crystallization often requires the resolution of reagents that are effective only for as pecific system; [3,4] enzyme-mediated kinetic resolution faces decreased catalytic activity over time; [5,6] and chromatographic methods present the disadvantage of being discontinuous and expensive.Although the development of simulated moving bed chromatography (SMB) and supercritical-fluid chromatography (SFC) allows for continuous operation on ap reparative scale, [7][8][9][10] specialized equipment, optimization studies for each substrate,a nd the cost of stationary phases detracts somewhat from the broad application of these methods.…”

Chiral Recognition of Alcohols in the Crystal Lattice of Simple Metal Complexes ofO,O′-Dibenzoyltartaric Acid: Enantiocomplementarity and Simultaneous Resolution

“…Previously we reported on the use of calcium complexes Ca(L 0 ) (7) and Ca(HL 0 ) 2 (8) for the resolution of carboxylic acids and hydroxy acid esters. [5] The neutral calcium salt 7 can be applied, however, to the resolution of certain alcohols by crystallizing the complexes 9-(L), where L stands for the alcohol (currently 1 ± 3) to be resolved.…”

“…A very stable complex (9-(6)) formed with 2-methoxyethanol (6) is the key compound upon the enantiomeric resolution of O,O'-dibenzoyltartaric acid by preferential crystallization. [6] A simple, mild work-up involves the transformation of 9-(L) into the mixed calcium salt [5,7] (10a) formed with methoxyacetic acid (HL M ), (5a) [Eq. (1)].…”

Efficient Preparation of (R)‐2‐chloromandelic Acid Via a Recycle Process of Resolution

“…But the efficient molar ratio of tartaric acid derivative neutral calcium salt and racemic compound may be another ratio. 21,22 Thus, different ratios were studied and the ratio of 0.8:1 was found to be the best in the resolving efficiency (Table 1, entry 6). Unfortunately, it was difficult to obtain the qualified single crystal of less soluble salts for X-ray crystallographic analysis.…”

“…The Mravik group applied optically active O,O'dibenzoyltartaric acid (DBTA), which is usually used for the resolution of amines, as a new resolving reagent for racemic carboxylic acid derivatives. [21][22][23] Compared with chiral amines, optically pure DBTA, the derivative of tartaric acid 2, is a relatively cheap and nontoxic reagent. Therefore, this method is promising for the resolution of racemic acids.…”