Unsaturated Carbon-carbon Bonds Research Articles

Sulfonyl Isocyanates and Sulfonyl Isothiocyanates

Abstract The literature dealing with sulfonyl isocyanates since 1972 is reviewed. Along with the sulfonyl isocyanates. the preparations and reactions of sulfonyl isothiocyanates are also reviewed. The paper is divided into three sections—Introduction, Preparations and Reactions. The chief sources of sulfonyl isocyanates are reactions of sulfonamides with phosgene, of sulfonyl ureas with phosgene, and of sulfonyl halides with metal cyanates. The principal sources of sulfonyl isothiocyanates are iminothiocarbamate salts when treated with thionyl chloride, phosphorus halides, or methyl chlorocarbonate. The iminothiocarbamate salts are prepared from sulfonamides. carbon disulfide. and metal hydroxides. The reactions of the isocyanates and isothiocyanates are categorized under reactions with arides, carbon-carbon unsaturated bonds, carbon-nitrogen double bonds, hydroxylgroups. amines. amino acids, amino alcohols, amides. aldehydes and ketones, C-H acidic compounds, phosphorus compounds, silicon compounds, tin ...

Superactive inhibitors of angiotensin converting enzyme: Analogs of BPP 9a containing dehydroproline

FEBS LettersVolume 107, Issue 2 p. 273-276 Full-length articleFree Access Superactive inhibitors of angiotensin converting enzyme Analogs of BPP9a containing dehydroproline George H. Fisher, George H. Fisher Department of Medicine (D58), University of Miami School of Medicine, PO Box 016960, Miami, FL 33101, USASearch for more papers by this authorJames W. Ryan, James W. Ryan Department of Medicine (D58), University of Miami School of Medicine, PO Box 016960, Miami, FL 33101, USASearch for more papers by this author George H. Fisher, George H. Fisher Department of Medicine (D58), University of Miami School of Medicine, PO Box 016960, Miami, FL 33101, USASearch for more papers by this authorJames W. Ryan, James W. Ryan Department of Medicine (D58), University of Miami School of Medicine, PO Box 016960, Miami, FL 33101, USASearch for more papers by this author First published: November 15, 1979 https://doi.org/10.1016/0014-5793(79)80388-9Citations: 10AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL References 1 A.V. Robertson, B. Witkop, J. Am. Chem. Soc., 84, (1962), 1697– 1701. 2 S.H. Ferreira, D.C. Bartelt, L.J. Greene, Biochemistry, 9, (1970), 2583– 2593. 3 M.A. Ondetti, N.J. Williams, E.F. Sabo, J. Pluscec, E.R. Weaver, O. Kocy, Biochemistry, 10, (1971), 4033– 4039. 4 Y.S. Bakhle, I.H. Page F.M. Bumpus Handbook of Experimental Pharmacology (1974), Springer-Verlag Berlin 41– 80. 5 F.E. Dorer, J.R. Kahn, K.E. Lentz, M. Levine, L.T. Skeggs, Circ. Res., 34, (1974), 824– 827. 6 H. Gavras, H.R. Brunner, J.H. Laragh, J.E. Sealey, I. Gavras, R.A. Vukovich, New Engl. J. Med., 291, (1974), 817– 821. 7 H. Gavras, H.R. Brunner, J.H. Laragh, I. Gavras, R.A. Vukovich, Clin. Sci. Mol. Med., 48, (1975), 57S– 60S. 8 D.B. Case, J.M. Wallace, H.J. Keim, M.A. Weber, J.I. Drayer, R.P. White, J.E. Sealey, J.H. Laragh, Am. J. Med., 61, (1976), 790– 796. 9 D.B. Case, J.M. Wallace, H.J. Keim, M.A. Weber, J.E. Sealey, J.H. Laragh, New Engl. J. Med., 296, (1977), 641– 646. 10 L.T. Skeggs, J.R. Kahn, N.P. Shumway, J. Exp. Med., 103, (1956), 295– 299. 11 K.K.F. Ng, J.R. Vane, Nature, 216, (1967), 762– 766. K.K.F. Ng, J.R. Vane, Nature, 218, (1968), 144– 150. 12 A.M. Felix, C.-T. Wang, A.A. Leibman, C.M. Delaney, T. Mowles, B.A. Burghardt, A.M. Charnecki, J. Meienhofer, Int. J. Pept. Prot. Res., 10, (1977), 299– 310. 13 G.H. Fisher, D.I. Marlborough, J.W. Ryan, A.M. Felix, Arch. Biochem. Biophys., 189, (1978), 81– 85. 14 G.R. Marshall, N. Back L. Martini R. Paolett Pharmacology of Hormonal Polypeptides and Proteins (1968), Plenum New York 48– 52. 15 B.F. Gisin, R.B. Merrifield, J. Am. Chem. Soc., 94, (1972), 3102– 3106. 16 J.W. Ryan, A. Chung, L.C. Martin, U.S. Ryan, Tissue Cell, 10, (1978), 555– 563. 17 M.A. Ondetti, B. Rubin, D.W. Cushman, Science, 196, (1977), 441– 444. 18 D.W. Cushman, H.S. Cheung, E.F. Sabo, M.A. Ondetti, Biochemistry, 16, (1977), 5484– 5491. 19 G.H. Fisher, J.W. Ryan, L.C. Martin, G. Pena, Adv. Exp. Med. Biol., (1979), in press 20 D.W. Cushman, J. Plusece, N.J. Williams, E.R. Weaver, E.F. Sabo, O. Kocy, H.S. Cheung, M.A. Ondetti, Experientia, 29, (1973), 1032– 1034. 21 S. Moore, A.M. Felix, J. Meienhofer, C.W. Smith, R. Walter, J. Med. Chem., 20, (1977), 495– 500. 22 D.I. Marlborough, J.W. Ryan, A.M. Felix, Arch. Biochem. Biophys., 176, (1976), 582– 590. Citing Literature Volume107, Issue2November 15, 1979Pages 273-276 ReferencesRelatedInformation

Selective hydrogenation of unsaturated carbon-carbon bonds with rhodium complexes

When mixtures of unsaturated substances, or compounds containing multiple sites of unsaturation are hydrogenated using RhCl(PPh3)3 as catalyst, it is possible that the substrate which reduces slowest as a single substrate can be hydrogenated preferentially in the mixture. The degree of selectivity achieved can be enhanced by the addition of polar solvents, the effects of which are discussed. The degree of participation of the two kinetically indistinguishable forward routes, i.e., via substrate attack on a hydrido intermediate, or hydrogen attack on a substrate intermediate, may also be of importance in determining the degree of selectivity achieved.

Mechanism and kinetics of HI addition to unsaturated carbon-carbon bonds in organic solvents: Addition of HI to methyl propiolate in chlorobenzene solution

New dienamino esters (3b–k) were obtained by addition of enamino esters (1b–g) to methyl and ethyl propiolate (2a–b). Z,E-Configuration and a transoid conformation were assigned on the basis of spectral data which indicate also noncoplanarity of phenyl groups whenever present. The corresponding adducts with acetylenedicarboxylic ester (18 and 19) have a cisoid conformation and it was possible to differentiate between thermodynamically and kinetically controlled products. Deuteration experiments showed the existence of a 1,5-proton transfer while comparative examination of a whole series of NMR spectra furnished evidence for a head to tail attachment. Attempts to trap the intermediate zwitterion 10 resulted in the formation of 15a–b corresponding to a cyclobutene intermediate. The reaction repiesents a new synthesis of the benzene nucleus and a practical method to obtain the methyltrimesic and 2,4,6-biphenyltricarboxylic acids. Additions of enamino esters to the triple bond are best interpreted as occurring through a common key intermediate, a zwitterion of type 5 or 10. The former collapses by proton transfer and the resulting imino-derivative 6 tautomerizes to 3. The latter cyclizes to a non-isolable cyclo-butene 12 which by opening of the ring produces the dipolar species 13 which further reacts with propiolic ester. By cyclization of the dienamino esters 3a–j but not of 18 and 19 in dipolar aprotic solvents at 160–190° the corresponding a-pyridones 4a–t were obtained in good yields.

Quantitative determination of unsaturation in oils by using an automatic‐titrating hydrogenator

A procedure was developed to adapt an automatic-titrating hydrogenator to the rapid determination of unsaturated carbon-carbon bonds in seed oils. Its utility as a research tool for detecting unusual types of unsaturation was demonstrated by analysis of 35 oils. When the hydrogen-iodine value of an oil determined by the hydrogenator differed significantly from the iodine value by the Wijs method, the presence of unsaturation such as acetylenic or conjugated double bonds was indicated. For repetitive analysis of samples of the same oil, or of oils having nearly the same extent of unsaturation, the hydrogenator can successfully accomodate injection of a new sample every 2 to 5 min. Possible utility of the method for monitoring samples from a processing plant is apparent.