Thiocarboxylate Research Articles

2‐Cyanoacrylates as reagents in heteroatomic synthesis (a review)

AbstractSeveral types of addition reactions to the CC bond of alkyl 2‐cyanoacrylates, CH2C(CN)COOR (1), are considered. The first examples deal with addition of CH‐Acids (pKa less than 13) and of H2S in the presence of catalytic amounts of strong amines, also of mercaptans, thiocarboxylic, and thiophosphoric acids. P‐Sulfenylchlorides and acidic phosphites add irreversibly at 20°C to form addition products in accordance with the distribution of charges in 1. HCl reversibly adds to 1 and to the acid chloride CH2C(CN)COCl (2). Alcohols and H2O also add reversibly to the acid CH2C(CN)COOH (3) and to esters of 1 to transform 1 and 3 into polymers. Triethylsilane in the presence of CF3COOH (4) reduces the CC bond of 1 and 3 to the corresponding saturated derivatives.The second set of examples involves reactions of 1 with P‐III compounds in the presence or absence of 4. Ph3P as well as other weak nucleophiles reversibly add to 1 in the absence of 4 to cause instant polymerization. However, 4 protonates an initially formed zwitter‐ion in the reaction of 1 with Ph3P,(EtO)2PCl,Ph2PCl and thiourea to afford stable addition products. IR spectroscopy reveals the formation of H‐complexes of 4 with the CN and COOR groups of 1, which stimulates the addition of the weak nucleophile (o‐C6H4O2)PCl to the CC bond of 1. This reagent does not react with 1 in the absence of 4. Strong nucleophiles, Alk3P, and (Et2N)3P in excess irreversibly add at 20°C to 1 to form zwitterions, which specifically react with PhNCO to give stable products. 1,3,2‐Dioxaphospholes react with 1 either to form spirophosphoranes or 2‐cyano‐3‐phosphoranylpropionates.

Synthesis and characterization of neutral oxorhenium(V) and nitridotechnetium(V) complexes with a tetradentate N 2S 2 unsaturated ligand derived from dithiocarboxylic acid

Neutral complexes of technetium(V) and rhenium(V) of the type TcN(L2) and ReO(L2)CI, where L2 corresponds to the dianionic form of the tetradentate N 2S 2 ligand N, N′-ethylene bis(methyl 2-aminocyclopentane-l-dithiocarboxylate), were prepared by substitution reaction on the starting materials 99TcNCl 2(PPh 3) 2 and ReOCl 3(PPh 3) 2, respectively. The complexes were characterized by elemental analysis, IR, NMR spectroscopy and conductimetry. The molecular and crystal structure of the nitrido complex TcN(L2) was determined by single-crystal X-ray diffraction technique (monoclinic P2 1/ c, a = 13.380(6), b = 9.945(2), c = 15.839 Å, β = 113.91(3)°). The electrochemical behaviour of the nitrido complex was investigated.

ChemInform Abstract: Boron Compounds. Part 104. Dithiocarboxylic Acids and Derivatives from Carboxylic Esters and Lactones with the Organoboron Sulfide Reagent (9‐ BBN)2S.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Reactions of some perfluoroolefins with S-containing nucleophiles

This paper discusses data on the reactions of perfluoroolefins (hexafluoropropylene dimers and trimers, perfluoro-1-ethylcyclohexene, perfluoro-1-azacyclohexene, perfluoro-5-azanonene-4) with bipolar S-containing nucleophiles (thiourea, NaSCN, sodium 1- N,N-diethylaminodithiocarbamate, Na 2S 2O 3) leading, along with traditional products of fluorine substitution at a multiple bond by the nucleophilic sulfur atom, to five-membered heterocycles with two heteroatoms and perfluorinated alkyl substituents. For example, in the reaction of thiourea with perfluoro-2-methylpentene-2 ( 1) in bipolar aprotic solvents, 4,4-bis(trifluoromethyl)-5-tetrafluoroethylidene)-2-amino- dihydrothiazole ( 2) was formed. In the reaction of compound 1 with NaSCN in the presence of bases, 5,5-bis(trifluoromethyl)-4-(tetrafluoroethylidene)-2-oxo-dihydrothiazole 4 was formed, along with compound 3, via the nucleophilic addition at the NCS group and subsequent intramolecular cyclization of the thiocarboxylic acid. The structure was identified by 13C and 19F NMR and X-ray structure analysis. Reaction mechanisms are discussed, as well as the effect of solvent and reaction conditions on formation of heterocyclic compounds. The role of perfluoroalkyl substituents in heterocycle stability is being investigated. ▪

ChemInform Abstract: Trifluoroacetic Acid in the Synthesis of Thiocarbamates and Thiocarboxylic Acid Esters.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Infrared band intensity variations during rotamer interconversion in simple alcohols and thiols

Abstract Ab initio prediction of infrared band intensities is considered in relation to assignment of bands to particular rotameric forms of ethenol, ethene thiol, formic and thioformic acids and nitrous acid. In particular, certain predicted dramatic band intensity changes between the rotamers of these molecules are examined in the light of experimental data where it is available, and it is shown that in some instances, strong bands should be attributed to the least energetically favoured rotamer. The overall consistency of ab initio relative intensity predictions with experimental observation for these molecules is discussed and it is concluded that for such molecules, theoretical, computed intensities form a reliable basis from which to start assignment of the spectrum.

SYNTHESE DE N-ALKYL-3-ARYL-2-DIPHENYLPHOSPHINOYL-1H-PYRIDO [2, 3-b] [1,4]THIAZINES

Abstract A variety of N-alkyl-3-aryl-2-diphenylphosphinoyl-1H-pyrido[2,3-b] [1,4]thiazines has been efficiently synthesized by treatment of the anion of 3-(N-alkyl-N-diphenylphosphinoylmethylamino)-2-chloro or -2,6-dichloropyridines with the appropriate aromatic O-ethyl thiocarboxylates. Diverses N-alkyl-3-alkyl-2-diphenylphosphinoyl-1H-pyrido [2,3-b] [1,4]thiazines ont ete preparees par action de differents thioesters aromatiques sur I'anion de 3-(N-alkyl-N-diphenylphosphinoylmethylamino)-2-chloro ou -2,6-dichloropyridines.

Dithiocarbonsäuren und Derivate aus Carbonsäureestern und Lactonen mit dem Organoborsulfid‐Reagenz (9‐BBN)2S

Dithiocarboxylic Acids and Derivatives from Carboxylic Esters and Lactones with the Organoboron Sulfide Reagent (9‐BBN)2S[1]Bis(1,5‐cyclooctanediylboryl) sulfide (1) reacts with carboxylic esters to give the dithiocarboxylic 1,5‐cyclooctanediylboryl esters 2a–f in high yields (2a: X‐ray crystal structure analysis). Methanolysis of 2a–f leads to the dithiocarboxylic acids 5a–f, which form the corresponding piperidinium salts in the presence of piperidine. When cyclic esters (γ‐, δ‐lactones) are allowed to react with 1, the boryloxy‐substituted dithiocarboxylic 1,5‐cyclooctanediylboryl esters 3a–c are obtained.

酸化マグネシウム粉体存在下チオカルボン酸とα, β-不飽和カルボン酸エステルとのマイケル付加反応

酸化マグネシウム粉体存在下チオカルボン酸とα, β-不飽和カルボン酸エステルとのマイケル付加反応

Isopenicilin N synthase: a new mode of reactivity

Incubation of L-δ-(α-aminoadipoyl)- L-(3,3-difluorohomocysteinyl)- D-valine [an analogue of the natural substrate: L-δ-(α-aminoadipoyl)- L-(cysteinyl)- D-valine] with isopenicillin N synthase (IPNS) resulted in the production of a thiocarboxylic acid, i.e. both equivalents of the dioxygen cosubstrate were utilised to oxidise a single carbon of the cysteinyl analogue. This result and others are rationalised in terms of mechanistic proposals for the first ring closure by IPNS. The synthesis of L-difluorohomocysteine and related structures, via 3,3-difluoro-β-lactams, is described.

Reactions of Carbon Disulfide withC-nucleophiles

Abstract The aim of this review is to present reactions of carbon disulfide with C-nucleophiles which form carbon-carbon bonds. Compounds with an activated methyl or methylene group react, in the presence of a base, as carbanions with the electrophile carbon disulfide to give dithiocarboxylates which can be converted to ketene dithioacetals on treatment with excess alkylation reagent. Acidification affords dithiocarboxylic acids. Bases of low nucleophilicity because of steric hindrance and sodium hydride, respectively, are often used for the deprotonation steps.

On carbon-13 spectra of thio- and dithiocarboxylic acids triorgano group 14 metal esters

The thiocarbonyl carbon chemical shifts of thio- and dithiocarboxyl acid triorgano group 14 metal esters have been studied in comparison with the carbonyl chemical shifts of the corresponding carboxylic and thiocarboxylic acid derivatives. Triorgano group 14 metal groups cause remarkable downfield shifts of the carbonyl and thiocarbonyl carbon chemical shifts in the esters. The thiocarbonyl carbon chemical shifts of the dithio esters ( i-C 3H 7CS 2EMe 3, E = group 14 element) are correlated linearly with the Allred-Rochow electronegativity of the metals, and with their ππ* transition energies except for the silyl esters. The 13CO chemical shifts of trimethyltin isobutyrate appear at the lowest field in the carboxylic acid triorgano group 14 metal esters (RCOOER′ 3, E = group 14 metal). The unusual downfield shifts reflect the polymetric structure of the tin esters. The empirical equation (δ(CS) = 1.45 δ(CO)−46.5 ppm) predicting 13CO and 13CS chemical shifts, which has been proposed by Kolinowski and Kessler, can not be applied for these triorgano group 14 metal esters and ortho substituted benzoates and thio- and dithiobenzoates.

Syntheses of fluorine-containing thio- and selenocarbonyl compounds based on polyfluorinated aliphatic aldehydes

The possibility of using polyfluorinated aliphatic aldehydes to synthesize thio- and selenoaldehydes, esters of perfluoralkandithiocarboxylic acids and amides of thiocarboxylic acids of cyclic and acyclic structure is shown. ▪ Cycloaddition reactions of the obtained thio- and seleno- derivatives with diens has been studied.

SOME NEW HOMOLYTIC HETEROCYCLIZATION REACTIONS IN CHEMISTRY OF BIVALENT SULFUR COMPOUNDS

Abstract The novel approach to one-pot synthesis of various heterocycles based on the heterocyclization reaction of bivalent sulfur compounds (thiols, dithiocarboxylic acids and their derivatives) are reported.

Synthesis of thiocarboxylic acid esters

Synthesis of thiocarboxylic acid esters

The Pericyclic Reaction of the Derivatives of Dithiocarboxylic Acids

Abstract Review of pericyclic reactions of the derivatives of dithiocarboxylic acids. 1. Anionic [3+2]-cycloaddition of dithioate anions to activated multiple bonds. 2. The esters of dithiocarboxylic acids in cycloaddition and sigmatropic shift reactions.

Isopenicillin N synthase: a new mode of reactivity

Incubation of δ-(L-α-aminoadipoyl)-L-(3,3-difluorohomocysteinyl)-D-valine with isopenicillin N synthase gave a thiocarboxylic acid, consistent with the formation of a monocyclic lactam intermediate.

Röntgenstrukturanalyse des dimeren 2,2‐Diphenylcyclopropanthiocarbonsäure‐S‐tert‐butylester‐Lithium‐Enolat · TMEDA‐Komplexes: ein „ganz normales”︁ Ester‐Enolat und ein „ganz normales”︁ Methylencyclopropan‐Derivat

X‐ray Crystal Structure of the Dimeric tert‐Butyl 2,2‐Diphenylcyclopropanecarbothioate Lithium Enolate · TMEDA Complex: an “Ordinary” Ester Enolate Containing an “Ordinary” Methylenecyclopropane MoietyAfter many unsuccessful attempts we now succeded in growing a suitable crystal of a cyclopropanecarbothioate lithium enolate (title compound 11c) for X‐ray crystal structure analysis. 11c crystallizes as a tetramethylethylenediamine (TMEDA) complex in large cubes and contains hexane, is unstable above − 20°C and twinned. 11c is not C‐lithiated, but exhibits features normal for an ester lithium enolate: a double bond with planar trigonal centers, a methylene cyclopropane moiety with bond lengths and angles almost identical with those in corresponding hydrocarbons, a dimeric aggregation with an almost planar Li‐O‐Li‐O ring, with the large hydrocarbon units in a cis arrangement (Figure 1,2). A comparison with other lithiated cyclopropanes is made (Figure 3). The X‐ray crystal structure analysis shows 11c to form a channel structure in which n‐hexane is included. The structure described here is the first one of a thiocarboxylic acid S‐ester lithium enolate.

Reactions ANC Rearangements of Carboxamides Phosphorylated by Tervalent Phosphorus Chlorides

Abstract We have found that N-substituted amides of carboxylic or thiocarboxylic acids (I) react with tervalent phosphorus chlorides to give N- and O(S)-phosphorylated derivatives (II) which isomerise into imidoyl(thio)phosphonates (III). The factors determining the ability of the initial products (II) and their iminated derivatives (IV) to participate in diad and triad rearrangements have also been studied.

Chemistry of C-Phosphorylated Thioformic Acid Derivatives

Abstract O-Alkylesters of dialkoxyphosphorylthioformic acids were formed in the Arbusov reaction of alkylchlorothionoformates with triesters of phosphorous acid