2471-92-3Relevant articles and documents
Enzyme-catalysed oxidation of 1,2-disulfides to yield chiral thiosulfinate, sulfoxide and cis-dihydrodiol metabolites
Boyd, Derek R.,Sharma, Narain D.,Shepherd, Steven D.,Allenmark, Stig G.,Allen, Christopher C. R.
, p. 27607 - 27619 (2014/07/21)
Enantioenriched and enantiopure thiosulfinates were obtained by asymmetric sulfoxidation of cyclic 1,2-disulfides, using chemical and enzymatic (peroxidase, monooxygenase, dioxygenase) oxidation methods and chiral stationary phase HPLC resolution of racemic thiosulfinates. Enantiomeric excess values, absolute configurations and configurational stabilities of chiral thiosulfinates were determined. Methyl phenyl sulfoxide, benzo[c]thiophene cis-4,5-dihydrodiol and 1,3-dihydrobenzo[c]thiophene derivatives were among unexpected types of metabolites isolated, when acyclic and cyclic 1,2-disulfide were used as substrates for Pseudomonas putida strains. Possible biosynthetic pathways are presented for the production of metabolites from 1,4-dihydrobenzo-2,3-dithiane, including a novel cis-dihydrodiol metabolite that was also derived from benzo[c]thiophene and 1,3-dihydrobenzo[c]thiophene.
Nucleophilic Substitution Factors. 1. Coplanar vs. Orthogonal Bimolecular Substitution at a Benzylic Carbon. X-ray Structure of 2-Isobutyl-1,3-dihydrobenzothiophenium Perchlorate
King, J. F.,Tsang, T. Y.,Abdel-Malik, M. M.,Payne, N. C.
, p. 3224 - 3232 (2007/10/02)
A stereoelectronic effect in bimolecular nucleophilic substitution at a benzylic center has been observed in the rates of reaction of thiourea in dimethyl-d6 sulfoxide with a series of sulfonium perchlorates with differing degrees of constraint in the orientation of the reacting C-S+ bond with respect to the plane of the aromatic ring.The substrates and their relative rates (at 37 deg C, unless otherwise noted) are as follows: (a, highly constrained) 2-ethyl-1,3-dihydrobenzothiophenium perchlorate (4b), 1,00, and 2-isobutyl-1,3-dihydrobenzothiophenium perchlorate (4c), 2.8; (b, partly constrained) 2-ethyl-3,4-dihydro-1H-2-benzothiopyranium perchlorate (7), 45 (at 82 deg C); (c, unconstrained) S,S-dibenzyl-S-ethylsulfonium perchlorate (5b), 8.1*103.An (8*103-fold rate difference was also observed between S,S-dibenzyl-S-ethylsulfonium terafluoroborate (5a) and 2-ethyl-1,3-dihydrobenzothiophenium tetrafluoroborate (4a) with potassium thiocyanate-18-crown-6 in acetonitrile-d3.Analysis of these rate differences, taken with inspection of molecular models which show that the observed rate differences are not adequately accounted for by simple nonbonding or angle strain effects, clearly indicates a dihedral angle dependent factor consistent with ?-overlap between p-orbitals on the aromatic ring and the carbon atom undergoing substitution.The "orbital-overlap factor" is estimated to increase the reactivity of the benzylic center in 5b (4*103-fold relative to that of the corresponding ethyl group (in 21).A single-crystal X-ray analysis on 4c showed the salt crystallizes in space group P21/n, unit cell dimensions a = 17.382 (1) Angstroem, b = 9.1731(6) Angstroem, c = 8.7828 (3) Angstroem, and β = 91.7 (2) deg, with Z = 4.On the basis of 2054 unique data with F2 > 2?, full matrix refinement converged at R = 0.044 for 232 variables.There is a dihedral angle of 3.8 deg between the C2,S,C9 plane and the plane of the aromatic ring consistent with the observed low reactivity of the benzylic center and the present analysis.The entropies of activation for benzylic substitution of the cyclic and acyclic substrates (4b, 4c, and 5b) with thiourea in Me2SO-d6 are very similar (-12 +/- 1 cal mol-1 K-1), in contrast to the great ΔS(excit.) difference reported for an analogous α-carbonyl system by Bartlett and Trachtenberg; the origin of this difference is discussed.
Chemistry of 8-Substituted 1-Naphtylmethylenes and 2-Substituted Benzylidenes. A simple Entry to 1H-Cyclobutanaphthalenes
Bailey, R. J.,Card, P. J.,Shechter, H.
, p. 6096 - 6103 (2007/10/02)
Study has been made of neighobing heteroatom interaction in thermolysis and photolysis of proximally substituted aryldiazomethanes.Thus, (8-bromo-1-naphthyl)diazomethane (1c) isomerize at 132 deg C to 9-bromo- (18a), 9-iodo- (18b), and 6,9-dichloro-3H-benzindazoles (18c).Indazoles 18a and 18b are reduced by lithium aluminum hydride to 3H-benzindazole (21), identical with that from decomposition of N-(1-methyl-2-naphthyl)-N-nitrosoacetamide (19). 1-Naphthyldiazomethane (1e) does not isomerize however to 21; in benzene at -78 deg c, 1e converts to trans-bis(1-naphthyl)ethylene (22b), 1-naphthalzine (26), and 7-(1-naphthyl)cycloheptatriene (24) wich rearranges to 1-(1-naphthyl)cycloheptatriene (25) whean heated.Irradiation of 1a in ethyl ether results in trans-bis(8-bromo-1-naphthyl)ethylene (22c) and 1-bromo-1Hcyclobutanaphthalene (4a), the first aryne bridged in its peri positions by a single carbon atom moiety.Aqueous silver nitrate converts 4a tp 1H-cyclobutanaphthyl nitrate (4b) and 1-naphthaldehyde (28), presumably by ring opening of 1-hydroxy-1H-cyclobutanaphhtalene (27).Reaction of 4a with magnesium and hydrolysis of the resulting Grignard reagent yield 1H-cyclobutanaphthalene (4d), a hydrocarbon acid wich udergoes deuterium exchange at C-1 considerably slower than to acenaphthene (29) and diphenylmethane (30).Thermolysis and photolysis of diazomethane (1d) to give 2-methyl-2H-naphthothiophene (33) are of note in that methylthio participation in 8-(methylthio)-1-naphthylidene (2d) and thia-Stevens rearrangement appear to be involved. (o-Iodophenyl)diazomethane (5a) thermolyzes to trans-bis(o-iodophenyl)ethylene and o-iodobenzalazine (36); products of reaction of the iodine moiety with the carbenic center in o-iodobenzylidene (6a) were not found.Thermolysis however of (o-(methylthio)phenyl)diazpmethane (5b) results in inrtamolecular C-H insertion to yield 4,5-dihydrothiophene (37) along with trans-bisethylene (38) and o-(methylthio)benzalazine(39).Intermolecular carbenic interception does occur in photolysis of 5b iin that 2-(2-ethoxy-1-propyl)thioanisole (40) is formed along with 398 and 39.The mechanisms of the various participation processes in the above substituted 1-naphthylidenes are discussed.
