{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T09:02:15Z","timestamp":1785402135687,"version":"3.56.0"},"reference-count":32,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T00:00:00Z","timestamp":1782345600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100012365","name":"Howard University","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100012365","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/05gt1vc06","id-type":"ROR","asserted-by":"publisher"}]},{"name":"National Science Foundation Major Research Instrumentation program","award":["NSF DMR-2117502"],"award-info":[{"award-number":["NSF DMR-2117502"]}]},{"award":["NSF DMR-2117502"],"award-info":[{"award-number":["NSF DMR-2117502"]}],"id":[{"id":"https:\/\/ror.org\/021nxhr62","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The reaction of either the L or D enantiomer of H2N-C*H(R)CO2\u2212 (R = -CH2SH cysteine, C; -C(SH)(CH3)2, penicillamine, PN; or -CH2CH2SH, homocysteine, HC) with an imidazole-4-carboxaldehyde and nickel(II) acetate in methanol yields a single stereoisomer of a thiazolidine (from C or PN) or a thiazine (from HC) nickel complex. Five pairs of enantiomeric products were prepared and characterized by IR, ESI MS, EA, and single crystal structure determination. There is retention of chirality for the thiazolidine and thiazine complexes on ring position 4, C\u03b1 of the parent amino acid, and transfer of chirality to the newly generated stereogenic centers, ring positions 3 (the amino acid nitrogen atom, NAA) and 2 (the aldehyde carbon atom, Cald). For the thiazolidines, the new stereogenic centers, NAA, and Cald, have identical stereochemical assignments to one another and to the assignment of the alpha carbon atom, either all R from the L enantiomers of C and PN or all S from the D enantiomers of C and PN. For the thiazine products from HC, the newly generated stereogenic centers, ring positions 3 (NAA) and 2 (Cald), are identical to one another but opposite to that of the retained stereogenic center (ring position 4, the alpha carbon atom). Regardless of stereochemical assignment (R or S), the hydrogen atoms of C\u03b1, NAA, and Cald, ring positions 4, 3, and 2, are always all cis to one another for the five pairs of enantiomers examined. This is a consequence of the fact that the thiazolidine and thiazine rings are fused to two other chelate rings of the complexes, which seems to explain the high stereospecificity observed in these systems.<\/jats:p>","DOI":"10.3390\/molecules31132234","type":"journal-article","created":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T08:14:12Z","timestamp":1782375252000},"page":"2234","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Chirality Transfer and Thiazolidine or Thiazine Formation in Reactions of L and D Enantiomers of \u03b2- or \u03b3-Sulfhydryl Amino Acids with Imidazole Carboxaldehydes and Nickel(II)"],"prefix":"10.3390","volume":"31","author":[{"given":"Cynthia T.","family":"Brewer","sequence":"first","affiliation":[{"name":"Department of Chemistry, Catholic University, Washington, DC 20064, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Greg","family":"Brewer","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Catholic University, Washington, DC 20064, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2770-7076","authenticated-orcid":false,"given":"Raymond J.","family":"Butcher","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Howard University, Washington, DC 20059, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"486","DOI":"10.1016\/j.ejmech.2019.07.043","article-title":"Role of sulfur heterocycles in medicinal chemistry: An update","volume":"180","author":"Pathania","year":"2019","journal-title":"Eur. J. Med. Chem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/S0140-6736(80)90494-8","article-title":"Treatment of cancer by an inducer of reverse transformation","volume":"315","author":"Brugarolas","year":"1980","journal-title":"Lancet"},{"key":"ref_3","unstructured":"Ehsanifar, M., and Montazeri, Z. (2022). Neuroprotective effects of thiazolidine-4-carboxylic acid derivatives on memory impairment and neurodegeneration. Insights Chem. Biochem., Available online: https:\/\/irispublishers.com\/icbc\/pdf\/ICBC.MS.ID.000531.pdf."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"143475","DOI":"10.1016\/j.molstruc.2025.143475","article-title":"Pyrazole linked thiazolidine-4-carboxylic acid derivatives as potent \u03b1-amylase inhibitors: Synthesis, bioactivity, and in silico evaluation","volume":"1348","author":"Omran","year":"2025","journal-title":"J. Mol. Struct."},{"key":"ref_5","first-page":"575","article-title":"Synthesis of (4R)-thiazolidine carboxylic acid and evaluation of antioxidant potential","volume":"33","author":"Begum","year":"2020","journal-title":"Pak. J. Pharm. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1016\/0167-4943(82)90030-9","article-title":"Thiazolidine-4-carboxylic acid, a physiologic sulfhydryl antioxidant with potential value in geriatric medicine","volume":"1","author":"Weber","year":"1982","journal-title":"Arch. Gerontol. Geriatr."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1038\/s42004-019-0224-2","article-title":"How formaldehyde reacts with amino acids","volume":"2","author":"Kamps","year":"2019","journal-title":"Commun. Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"6236","DOI":"10.1021\/ja00752a040","article-title":"The mechanism of reactions involving Schiff base intermediates. Thiazolidine formation from L-cysteine and formaldehyde","volume":"93","author":"Kallen","year":"1971","journal-title":"J. Am. Chem. Soc."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"6227","DOI":"10.1021\/ja00752a039","article-title":"Equilibria for the reaction of cysteine and derivatives with formaldehyde and protons","volume":"93","author":"Kallen","year":"1971","journal-title":"J. Am. Chem. Soc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"4176","DOI":"10.1021\/acs.cgd.0c00466","article-title":"Chiral oxazolidine complexes derived from phenolic Schiff bases","volume":"20","author":"Mayans","year":"2020","journal-title":"Cryst. Growth Des."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1080\/17415993.2016.1156116","article-title":"Crystal structure, computational studies, and stereoselectivity in the synthesis of 2-aryl-thiazolidine-4-carboxylic acids via in situ imine intermediate","volume":"37","author":"Jagtap","year":"2016","journal-title":"J. Sulfur Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1805","DOI":"10.1080\/00958972.2013.791393","article-title":"DNA binding, nuclease, and colon cancer cell inhibitory activity of a Cu(II) complex of a thiazolidine-4-carboxylic acid derivative","volume":"66","author":"Thalamuthu","year":"2013","journal-title":"J. Coord. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.molstruc.2017.10.090","article-title":"Synthesis, characterization and crystal structure of (2RS,4R)-2-(2-hydroxy-3-methoxyphenyl) thiazolidine-4-carboxylic acid","volume":"1155","author":"Muche","year":"2018","journal-title":"J. Mol. Struct."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1078","DOI":"10.1039\/C7NJ02961F","article-title":"X-ray crystal structures and anti-breast cancer property of 3-tert-butoxycarbonyl-2-arylthiazolidine-4-carboxylic acids","volume":"42","author":"Jagtop","year":"2018","journal-title":"New J. Chem."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jorganchem.2018.09.027","article-title":"Chiral thiazolidines in the enantioselective ethylation of aldehydes: An experimental and computational study","volume":"878","author":"Tavares","year":"2018","journal-title":"J. Organomet. Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1038\/s42004-021-00614-y","article-title":"Open questions on the transfer of chirality","volume":"4","author":"Reid","year":"2021","journal-title":"Commun. Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"100161","DOI":"10.1016\/j.giant.2023.100161","article-title":"Preparation of chiral polymers: Precise chirality transfer from natural species to achiral artificial polymers","volume":"14","author":"Miao","year":"2023","journal-title":"Giant"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"830","DOI":"10.1039\/b806203j","article-title":"Chiral transfer in coordination complexes: Towards molecular materials","volume":"38","author":"Crassous","year":"2009","journal-title":"Chem. Soc. Rev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1039\/D1DT03833H","article-title":"Self-assembled lanthanide-based helixes: Synthetic control of the helical handedness by chirality of the ligand","volume":"51","author":"Wu","year":"2022","journal-title":"Dalton Trans."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Brewer, C., Brewer, G., and Butcher, R.J. (2025). Chirality transfer and oxazolidine formation in reaction of L and D enantiomers of \u03b2-hydroxy amino acids with nitrogenous carboxaldehydes and nickel (II). Molecules, 30.","DOI":"10.3390\/molecules30142913"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"493","DOI":"10.1002\/zaac.201200526","article-title":"Reactivity studies of LAlH2 [L=HC(CMeNAr)2, Ar=2,6-iPr2C6H3] with 2-[(2-Hydroxybenzylidene)amino]-3-mercaptopropionic Acid and Benzene-1,2-diamine","volume":"639","author":"Ma","year":"2013","journal-title":"Z. Anorg. Allg. Chem."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1324","DOI":"10.3390\/molecules29061324","article-title":"Selective Generation of Aldimine and Ketimine Tautomers of the Schiff Base Condensates of Amino Acids with Imidazole Aldehydes or of Imidazole Methanamines with Pyruvates\u2014Isomeric Control with 2- vs. 4-Substituted Imidazoles","volume":"29","author":"Brewer","year":"2024","journal-title":"Molecules"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1016\/j.ica.2014.04.006","article-title":"Synthesis, supramolecular assemblies and luminescence of nickel (II) complexes based on a series of N-(2-pyridylmethyl) amino acid derivatives","volume":"418","author":"Zhang","year":"2014","journal-title":"Inorg. Chim. Acta"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"214051","DOI":"10.1016\/j.ccr.2021.214051","article-title":"Inorganic stereochemistry: Geometric isomerism in bis-tridentate ligand complexes","volume":"445","author":"Juraj","year":"2021","journal-title":"Coord. Chem. Rev."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"8513","DOI":"10.1021\/jp503154x","article-title":"Contribution of weak S-H\u2014O hydrogen bonds to the side chain motions in D,L-homocysteine on cooling","volume":"118","author":"Minkov","year":"2014","journal-title":"J. Phys. Chem. B"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2220","DOI":"10.1016\/j.poly.2010.04.022","article-title":"Chiral heterocyclic ligands XVI: Synthesis and crystal structures of four metal complexes of a tridentate, biheterocyclic ligand derived from l-cysteine","volume":"29","author":"Lewis","year":"2010","journal-title":"Polyhedron"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"11410","DOI":"10.1021\/acs.inorgchem.2c01738","article-title":"Toward Coordination Cages with Hybrid Chirality: Amino Acid-Induced Chirality on Metal Centers","volume":"61","author":"Grajda","year":"2022","journal-title":"Inorg. Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"512","DOI":"10.1039\/D0MA00125B","article-title":"Chirality control of inorganic materials and metals by peptides or amino acids","volume":"1","author":"Kim","year":"2020","journal-title":"Mater. Adv."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"131931","DOI":"10.1016\/j.molstruc.2021.131931","article-title":"Structure co-ordination of solitary amino acids as ligands in metal-organic frameworks (MOFs): A Comprehensive Review","volume":"1251","author":"Subramaniyam","year":"2022","journal-title":"J. Mol. Struct."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"467","DOI":"10.1107\/S0108767390000277","article-title":"Phase annealing in SHELX-90: Direct methods for larger structures","volume":"A46","author":"Sheldrick","year":"1990","journal-title":"Acta Crystallogr."},{"key":"ref_31","unstructured":"Sheldrick, G.M. (1997). SHELXL-97: Program for Crystal Structure Refinement, ScienceOpen, Inc."},{"key":"ref_32","unstructured":"Sheldrick, G.M. (1998). SHELXL-97: FORTRAN Program for Crystal Structure Analysis, Institute Fr Anorganisheche Chemie der Universitat, Gottingen University."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/13\/2234\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,27]],"date-time":"2026-06-27T05:02:35Z","timestamp":1782536555000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/13\/2234"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,25]]},"references-count":32,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["molecules31132234"],"URL":"https:\/\/doi.org\/10.3390\/molecules31132234","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,25]]}}}