02893nas a2200241 4500008004100000022001400041245015700055210006900212260009400281300001200375490000700387520187800394653004302272653002802315653003202343653002302375653002802398100002402426700002202450700002302472700002502495856013102520 2016 eng d a1741-599300aCrystal structure, computational studies, and stereoselectivity in the synthesis of 2-aryl-thiazolidine-4-carboxylic acids via insitu imine intermediate0 aCrystal structure computational studies and stereoselectivity in a2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcMAR a401-4250 v373 a

This article presents the synthesis of (2R/2S,4R)-2-aryl-thiazolidine-4-carboxylic acids via nucleophilic addition of L-Cysteine on aromatic aldehydes involving a yield and time-effective room temperature reaction in an aqueous DMSO medium in the presence of NaHCO3 as a base. The synthesized diastereomers were spectroscopically characterized and quantified for diastereomeric excess by liquid chromatography-mass spectrometry analysis. The impact of the type and position of substituent in aromatic aldehydes on reaction time, % yield, H-1 NMR shift at newly formed chiral center [C(2)-H], and diastereomeric excess (de%) have been investigated. A plausible mechanism for stereoselectivity via an in situ imine intermediate is proposed using real-time IR monitoring of the synthetic reaction based on the significant signals at 1597, 1593cm(-1) for imine (C=N) stretching. The imine mechanism for stereoselectivity was further supported by NMR studies of azomethine C-13 NMR signals at 159, 160ppm and by the single crystal structure of hitherto unknown (2S,4R)-3-(tert-butoxycarbonyl)-2-(2-hydroxyphenyl)thiazolidine-4-carbox ylic acid (3a) obtained as a major diastereomer in the synthesis of the butyloxy carbonyl (BOC) derivative of (2R/2S,4R)-2-(2-hydroxyphenyl)thiazolidine-4-carboxylic acid. The significant ortho-OH effect of phenolic hydroxyl group leading to strong hydrogen bondings plays a vital role in the formation of 2S,4R BOC derivative stereoselectively. The frontier molecular orbitals, possible electronic excitations, IR band characterizations, and reactivity parameters of newly reported compound (3a) have been predicted using quantum chemical descriptors from density functional theory. The theoretical exploration of experimental spectra using time-dependent DFT indicated a (-*) transition between HOMO and LUMO in the ultraviolet region.

10a2-aryl-thiazolidine-4-carboxylic acids10adensity function theory10afrontier molecular orbitals10aimine intermediate10aX-ray crystal structure1 aJagtap, Rohidas, M.1 aRizvi, Masood, A.1 aDangat, Yuvraj, B.1 aPardeshi, Satish, K. uhttps://library.ncl.res.in/content/crystal-structure-computational-studies-and-stereoselectivity-synthesis-2-aryl-thiazolidine01559nas a2200193 4500008004100000022001400041245012400055210006900179260000800248300001400256490000700270520084900277100002401126700002501150700002401175700002101199700002501220856012001245 2018 eng d a1144-054600aX-ray crystal structures and anti-breast cancer property of 3-tert-butoxycarbonyl-2-arylthiazolidine-4-carboxylic acids0 aXray crystal structures and antibreast cancer property of 3tertb cJAN a1078-10860 v423 a

Diastereomeric `2RS, 4R'-2-arylthiazolidine-4-carboxylic acids (ATCAs) were synthesized and their resolution to chiraly pure N-BOC derivatives was attempted by column chromatography. The absolute stereochemistry of the resolved compounds was ascertained by X-ray single crystal structures. Further application of the synthesized compounds was studied for their in vitro anti-breast cancer activity against MCF7 cell line using DOX as a standard by MTT assay method. Cell morphology analysis was carried out by fluorescence microscopy. The compounds containing `2S' absolute configuration in thiazolidine ring and presence of 2-NO2, 2,6-Cl groups on `2R'-aryl substituent showed significant antibreast cancer activity where some of the compounds were found to be more active than DOX in terms of induced apoptosis mode of MCF7 cell death.

1 aJagtap, Rohidas, M.1 aThorat, Shridhar, H.1 aGonnade, Rajesh, G.1 aKhan, Ayesha, A.1 aPardeshi, Satish, K. uhttps://library.ncl.res.in/content/x-ray-crystal-structures-and-anti-breast-cancer-property-3-tert-butoxycarbonyl-202441nas a2200265 4500008004100000022001400041245017700055210006900232260000900301300001600310490000600326520144600332653002401778653002201802653001701824653003101841653003501872100002401907700002201931700002401953700002001977700002201997700002502019856013102044 2019 eng d a2365-654900aCyanuric-chloride-mediated synthesis of 2-Aryl-3-tert-butoxycarbonyl-thiazolidine-4-carboxylic acid anilides: mechanistic, X-ray crystal structures and cytotoxicity studies0 aCyanuricchloridemediated synthesis of 2Aryl3tertbutoxycarbonylth cNOV  a12534-125460 v43 a

The `2R,4R'-2-aryl thiazolidine-4-carboxylic acid anilides (ATCAAs) were synthesized using cyanuric chloride (CC) as a clean and substoichiometric acid-amine coupling agent under optimized reaction conditions. The diesterphenol intermediate based mechanism is proposed and supported by spectral characterization of the intermediate. The single crystal X-ray structures of acid substrate (2R,4R)-3-(tert-butoxycarbonyl)-2-(2-methoxyphenyl)thiazolidine-4-carbox ylic acid (3 a) and anilides (R)-tert-butyl 4-(2-fluorophenylcarbamoyl)thiazolidine-3-carboxylate (4 b), (2R,4R)-tert-butyl 2-(2,6-dichlorophenyl)-4-(m-tolylcarbamoyl)thiazolidine-3-carboxylate (6 b) confirmed the formation of chiral anilides. The synthesized library of anilides [(R)-tert-butyl 4-Aryl thiazolidine-3-carboxylate and (2R,4R)-tert-butyl 2-Aryl-4-Aryl thiazolidine-3-carboxylate] 4 a-6 f was screened for their in vitro anti cancer, neuronal and neuroprotective studies. The anilides 4 b, 4 g, 5 d, 5 h, 6 c and 6 f (where the aryl=2-fluorophenylcarbamoyl, 4-chlorophenylcarbamoyl, 2-methoxyphenyl, 2,5-dichlorophenylcarbamoyl, 2,6-dichlorophenyl, 4-chlorophenylcarbamoyl respectively)were found to be less cytotoxic towards N2 A, SHSY-5Y neuronal cell lines in their differentiated and undifferentiated forms, and also exhibited dose dependant anti-inflammatory properties for a possible identification towards neurodegenerative and inflammatory disorders.

10aAcid-amine coupling10aCyanuric chloride10aCytotoxicity10aMechanistic investigations10aSingle crystal x-ray structure1 aJagtap, Rohidas, M.1 aShaikh, Samir, R.1 aGonnade, Rajesh, G.1 aRaheem, Shabnam1 aRizvi, Masood, A.1 aPardeshi, Satish, K. uhttps://library.ncl.res.in/content/cyanuric-chloride-mediated-synthesis-2-aryl-3-tert-butoxycarbonyl-thiazolidine-4-carboxylic