Novel thiazolidine derivatives as chiral catalysts in the enantioselective addition of diethylzinc to aldehydes

Synthesis and spectral characterization of zinc(II), copper(II), nickel(II) and manganese(II) complexes derived from bis(2-hydroxy-1-naphthaldehyde) malonoyldihydrazone

“…Any d-d band occurring in the visible region is masked by strong charge transfer bands. The high-spin manganese (II) complexes (10) and (11) do not show any band in the visible region which may be assigned to d-d band. Any weak band occurring in the visible region is masked by either the ligand band or charge-transfer band, as is typical for high-spin manganese(II) complexes.…”

“…Dihydrazones derived from condensation of acyl, aroyl-, pyridoyldihydrazones with o-hydroxy aromatic aldehydes and ketones are related ligands possessing four oxygen and four nitrogen donor atoms [9]. As the growth of interest in the use of polyfunctional ligands containing electron-withdrawing bulky fragments in their molecular skeleton becomes more significant [7,10], we are interested in the synthesis and characterization of the metal complexes derived from polyfunctional ligands containing electron-withdrawing bulky naphthyl fragments in their molecular skeleton and to see as if they could readily be prepared and how the chemical reactivity of these complexes varies relative to their corresponding salicylaldehyde dihydrazone complexes. In addition, as some of these complexes have potential to show several types of properties, it is interesting to explore how this feature could be modified by the presence of electron-withdrawing groups.…”

Design, Synthesis, and Safener Activity of Novel Methyl (R)-N-Benzoyl/Dichloroacetyl-Thiazolidine-4-Carboxylates

“…Due to the importance of thiazolidine derivatives, various synthetic routes to these compounds have been reported in many fields. The most frequently used method is the condensation of cysteine methyl ester hydrochloride with ketones in the presence of K 2 CO 3 [ 18 , 19 ]. As for N -benzoylthiazolidines, they are usually prepared by the acylation of the corresponding thiazolidine compound, which is treated with an acyl chloride in the presence of the base [ 20 ].…”

d-Penicillamine and l-cysteine derived thiazolidine catalysts: an efficient approach to both enantiomers of secondary alcohols

“…[10][11][12][13][14][15][16][17] Chiral 1,3-thiazolidine-4-carboxylates derived from the naturally occurring amino acid L-cysteine have been sparingly used for inducing chirality in the enantioselective alkylation of aldehydes with diethylzinc, originating secondary alcohols with good to excellent enantiomeric excesses. [18][19][20][21][22][23] These ligands are easily obtained in a simple two-step synthetic sequence involving the esterification of L-cysteine followed by condensation with a carbonyl compound, aldehyde or ketone, to give a rigid five-membered heterocycle 1 (Scheme 1). To the best of our knowledge, there is no reference of the use of structurally identical D-penicillamine derived thiazolidines 2 (Scheme 1) in enantioselective alkylation reactions.…”