123,054 research outputs found
Laser flash photolysis study of substituent effects on the rate of 1, 2-H migration in a series of benzylchlorocarbenes
No full textLaser flash photolysis of para-substituted 3-chloro-3-benzyldiazirines in isooctane produces the corresponding carbenes, which react with pyridine to form ylides or undergo 1,2-H migration to form the (Z)- and (E)-beta-chlorostyrenes. The rate for the 1,2-H migration is determined by plotting the pseudo-first-order rate constants for the growth of the ylide vs [pyridine] and extrapolating to zero pyridine concentration. In the case of (p-chlorobenzyl)chlorocarbene, the carbene decay can be monitored directly at 310 nm, whereas in [p-(trifluoromethyl)benzyl]chlorocarbene, the 285-nm trace may bc analyzed as the sum of the absorption of the carbene and of the product beta-chlorostyrenes. A Hammett plot of the logarithms of the rate constants for 1,2-H migration vs sigma(p) values gave a rho-value of -1.0, consistent with a hydride-like 1,2-H shift to the carbene center. The rate constants for the cyclopropanation of carbenes with tetramethylethylene (TME) were determined. In particular, the cyclopropanation of (p-chlorobenzyl)chlorocarbene with TME gave a negative activation energy of -4.7 kcal mol-1.PT: J; CR: BONNEAU R, 1989, J AM CHEM SOC, V111, P5973 BONNEAU R, 1989, J PHYS CHEM-US, V93, P4802 CARMICHAEL I, 1986, J PHYS CHEM REF DATA, V15, P1 DOYLE MP, 1987, J ORG CHEM, V52, P1619 EVANSECK JD, 1990, J PHYS CHEM-US, V94, P5518 GOULD IR, 1985, TETRAHEDRON, V41, P1987 GRAHAM WH, 1965, J AM CHEM SOC, V87, P4396 HO GJ, 1989, J AM CHEM SOC, V111, P6875 HOUK KN, 1984, J AM CHEM SOC, V106, P4291 JACKSON JE, 1989, J AM CHEM SOC, V111, P6874 JONES M, 1980, REACTIVE INTERMEDIAT, V2 JONES WM, 1980, REARRANGEMENTS GROUN KIRMSE W, 1971, CARBENE CHEM LAVILLA JA, 1989, J AM CHEM SOC, V111, P6877 LIU MTH, 1908, J ORG CHEM, V52, P4223 LIU MTH, 1985, J CHEM SOC CHEM COMM, P982 LIU MTH, 1987, CHEM DIAZIRINES, CH5 LIU MTH, 1989, J AM CHEM SOC, V111, P6873 LIU MTH, 1989, J CHEM SOC CHEM COMM, V12 LIU MTH, 1990, J AM CHEM SOC, V112, P3915 LIU MTH, 1992, J PHOTOCH PHOTOBIO A, V63, P115 MORGAN S, 1991, J AM CHEM SOC, V113, P2782 MOSS RA, 1986, J AM CHEM SOC, V108, P7028 MOSS RA, 1990, J AM CHEM SOC, V112, P5642 SCHAEFER HF, 1979, ACCOUNTS CHEM RES, V12, P288; NR: 25; TC: 27; J9: J AMER CHEM SOC; PG: 4; GA: HT801Source type: Electronic(1
Thermal decomposition of diazirines in the presence of meta-chloroperoxybenzoic acid. A method to determine the partitioning of reaction pathways
No full textPT: J; CR: AKIBA K, 1977, HETEROCYCLES, V7, P1131 BOYD RJ, 1978, 61ST CAN CHEM C WINN BRADLEY GF, 1977, J CHEM SOC P2, P1214 BRASLAVSKY S, 1977, CHEM REV, V77, P473 CURCI R, 1971, J ORG CHEM, V36, P3774 GRAHAM WH, 1965, J AM CHEM SOC, V87, P4396 JENNINGS BM, 1976, J AM CHEM SOC, V98, P6416 KIRMSE W, 1971, CARBENE CHEM KOPECKY KR, 1969, CAN J CHEM, V47, P709 LAU A, 1964, SPECTROCHIM ACTA, V20, P97 LIU MTH, 1972, J PHYS CHEM-US, V76, P797 LIU MTH, 1974, CAN J CHEM, V52, P246 LIU MTH, 1974, TETRAHEDRON LETT, P1329 LIU MTH, 1975, TETRAHEDRON, V31, P1645 LIU MTH, 1977, CAN J CHEM, V55, P3596 MEIER H, 1977, ANGEW CHEM INT EDIT, V16, P835 SCHMIDT G, 1963, BIOCHEMISTRY-US, V2, P126 SCHMITZ E, 1964, ANGEW CHEM INT EDIT, V3, P333 SCHMITZ E, 1967, CHEM BER, V100, P2101 SCHWARTZ NN, 1964, J ORG CHEM, V29, P1976 SYNDER JP, 1971, J AM CHEM SOC, V93, P3816 TURRO NJ, 1974, ACCOUNTS CHEM RES, V7, P97; NR: 22; TC: 3; J9: CAN J CHEM; PG: 5; GA: HD871Source type: Electronic(1
on the thermal decomposition of diazirines
No full textPT: J; CR: BIGOT B, 1978, J AM CHEM SOC, V100, P6576 BRADLEY GF, 1977, J CHEM SOC P2, P1214 BRUNNER J, 1980, J BIOL CHEM, V255, P3313 DIDERICH G, 1972, HELV CHIM ACTA, V55, P2103 FLEMING I, 1980, FRONTIER ORBITALS OR GRILLER D, 1982, J AM CHEM SOC, V104, P5549 JENNINGS BM, 1976, J AM CHEM SOC, V98, P6416 LAHMANI F, 1976, J PHYS CHEM-US, V80, P2623 LANGANIS ED, 1983, J AM CHEM SOC, V105, P7457 LIU MTH, 1972, J PHYS CHEM-US, V76, P797 LIU MTH, 1973, CAN J CHEM, V51, P2393 LIU MTH, 1974, J CHEM SOC P2, P937 LIU MTH, 1977, CAN J CHEM, V55, P3596 LIU MTH, 1982, CHEM SOC REV, V11, P127 MOORE CB, 1964, J CHEM PHYS, V41, P3504 SCHMITZ E, 1965, CHEM BER, V98, P2509 SCHMITZ E, 1967, CHEM BER, V100, P2093 SCHMITZ E, 1971, 23RD INT C PUR ALL C, V2, P283 SHEPARD RA, 1967, J ORG CHEM, V32, P3197 SHILOV AE, 1968, TETRAHEDRON LETT, P4177 SMITH NP, 1979, J CHEM SOC P2, P213 SMITH RAG, 1975, J CHEM SOC P2, P686 SNYDER JP, 1972, TETRAHEDRON LETT, P4347 TAYLOR EC, 1979, CHEM REV, V79, P181 TURRO NJ, 1980, J AM CHEM SOC, V102, P7576 TURRO NJ, 1982, J AM CHEM SOC, V104, P1754 VOIGT E, 1975, CHEM BER, V108, P3326 ZOLLINGER H, 1978, ANGEW CHEM INT EDIT, V17, P141; NR: 28; TC: 8; J9: J CHEM SOC PERKIN TRANS 2; PG: 4; GA: A2035Source type: Electronic(1
Benzylchlorocarbene: UV absorption spectrum, kinetics for 1,2-H migration and mechanism for reaction with acetic acid as determined by combined continuous and laser-flash photolysis
No full textPT: J; CR: BURFIELD DR, 1981, J ORG CHEM, V46, P629 GOULD IR, 1985, ETRAHEDRON, V41, P1987 GRAHAM WH, 1965, J AM CHEM SOC, V87, P4396 HOUK KN, 1984, J AM CHEM SOC, V106, P4291 HOUK KN, 1984, J AM CHEM SOC, V106, P4293 LIAU MTH, 1987, CHEM DIAZIRINES LIU MTH, UNPUB J AM CHEM SOC LIU MTH, 1984, TETRAHEDRON, V40, P887 LIU MTH, 1989, J CHEM SOC CHEM COMM, V12 MAERCKER A, 1982, CHEM BER, V115, P540 MOSS RA, 1986, J AM CHEM SOC, V108, P7028; NR: 11; TC: 5; J9: LASER CHEM; PG: 9; GA: ED999Source type: Electronic(1
Benzylchlorocarbene : kinetics parameters for 1,2-H migration, UB absorption spectrum, and mechanism for addition to alkenes
No full textPT: J; CR: ALTMANN JA, 1974, J AM CHEM SOC, V96, P4196 ALTMANN JA, 1975, J AM CHEM SOC, V97, P5217 BIRKS JB, 1970, PHOTOPHYSICS AROMATI, P303 BODAR N, 1972, J AM CHEM SOC, V94, P9103 BONNEAU R, 1989, J PHYS CHEM-US, V93, P4802 BURFIELD DR, 1981, J ORG CHEM, V46, P629 BURNETT SM, 1983, CHEM PHYS LETT, V100, P124 FRENKING G, 1984, TETRAHEDRON, V40, P2123 GOULD IR, 1985, TETRAHEDRON, V41, P1987 GRAHAM WH, 1965, J AM CHEM SOC, V87, P4396 HOUK KN, 1984, J AM CHEM SOC, V106, P4291 HOUK KN, 1984, J AM CHEM SOC, V106, P4293 JACKSON JE, 1988, J AM CHEM SOC, V110, P5595 JACKSON JE, 1989, J AM CHEM SOC, V111, P6874 KYBA EP, 1977, J AM CHEM SOC, V99, P8330 LIU MTH, 1985, J CHEM SOC CHEM COMM, P982 LIU MTH, 1986, J PHYS CHEM-US, V90, P75 LIU MTH, 1989, J CHEM SOC CHEM COMM, P12 MOSS RA, 1986, J AM CHEM SOC, V108, P7028 NOBES RH, 1980, CHEM PHYS LETT, V74, P269 RAGHAVACHARI K, 1982, CHEM PHYS LETT, V85, P145 SCHAEFER HF, 1979, ACCOUNTS CHEM RES, V12, P288 STEVENS IDR, 1989, TETRAHEDRON LETT, V30, P481 SU DTT, 1978, J AM CHEM SOC, V100, P1872 WARNER PM, 1984, TETRAHEDRON LETT, V25, P4211 WUBBELS GG, 1983, ACCOUNTS CHEM RES, V16, P285 ZUGRAVESCU I, 1976, N YLID CHEM; NR: 27; TC: 63; J9: J AMER CHEM SOC; PG: 5; GA: DC941Source type: Electronic(1
The thermal decomposition of diazirines: 3-(3-methyldiazirin-3-yl)propan-1-ol and 3-(3-methyldiazirin-3-yl)propanoic acid
No full textPT: J; CR: BIGOT B, 1978, J AM CHEM SOC, V100, P6575 BRIDGE MR, 1969, J CHEM SOC A, P91 CHURCH RFR, 1970, J ORG CHEM, V35, P2465 CLOSS GL, 1965, J AM CHEM SOC, V87, P4270 EFFIO A, 1980, J AM CHEM SOC, V102, P1734 FIGUERA JM, 1976, AN QUIM, V72, P737 FIGUERA JM, 1978, J CHEM SOC F1, V74, P809 FIGUERA JM, 1979, J PHOTOCHEM, V10, P473 FREY HM, 1963, J CHEM SOC, P3514 FREY HM, 1964, J CHEM SOC, P4700 FREY HM, 1965, J CHEM SOC, P1700 FREY HM, 1965, J CHEM SOC, P3101 FREY HM, 1966, J CHEM SOC A, P968 FREY HM, 1977, J CHEM SOC F1, V73, P2010 FREY HM, 1979, J CHEM SOC A, P1916 GANZER GA, 1986, J AM CHEM SOC, V108, P1517 GRILLER D, 1982, J AM CHEM SOC, V104, P5549 LAL D, 1974, J AM CHEM SOC, V96, P6355 LIU MTH, 1972, INT J CHEM KINET, V4, P229 LIU MTH, 1972, J PHYS CHEM-US, V76, P797 LIU MTH, 1973, CAN J CHEM, V51, P2393 LIU MTH, 1974, J CHEM SOC P2, P937 LIU MTH, 1977, CAN J CHEM, V55, P3596 LIU MTH, 1982, CHEM SOC REV, V11, P127 LIU MTH, 1984, J CHEM SOC CHEM COMM, P1062 LIU MTH, 1984, TETRAHEDRON, V40, P887 LIU MTH, 1985, J CHEM SOC CHEM COMM, P982 LIU MTH, 1986, J CHEM SOC PERK T 2, P211 LIU MTH, 1987, CHEM DIAZIRINES, V1, P111 MANSOOR AM, 1966, TETRAHEDRON LETT, P1753 MANSOOR M, 1967, THESIS U SOUTHAMPTON MOSS RA, 1984, TETRAHEDRON LETT, V25, P1023 NEUVARAND EW, 1967, J PHYS CHEM-US, V71, P1229 SCHMID P, 1979, INT J CHEM KINET, V11, P333 SHERIDAN RS, 1984, J AM CHEM SOC, V106, P436 SKELL PS, 1972, TETRAHEDRON, V28, P3571 SMITH NP, 1979, J CHEM SOC P2, P213 SMITH RAG, 1975, J CHEM SOC P2, P686 VOIGT E, 1975, CHEM BER, V108, P3326; NR: 39; TC: 8; J9: J CHEM SOC PERKIN TRANS 2; PG: 7; GA: DD960Source type: Electronic(1
The thermolysis and photolysis of diazirines
No full textPT: J; CR: AMRICH MJ, 1964, J AM CHEM SOC, V86, P292 ARCHER WH, 1976, J CHEM SOC F1, V72, P1448 BAYLEY H, 1978, BIOCHEMISTRY-US, V17, P2420 BIGOT B, 1978, J AM CHEM SOC, V100, P6575 BOTTOMLEY GA, 1964, AUST J CHEM, V17, P406 BRADLEY GF, 1977, J CHEM SOC P2, P1214 BRASLAVSKY S, 1977, CHEM REV, V77, P473 BRIDGE MR, 1969, J CHEM SOC A, P91 BRUNNER J, 1980, J BIOL CHEM, V255, P3313 BURKHOLDER CD, 1980, J AM CHEM SOC, V102, P2841 CADMAN P, 1974, J SA CHEM I, V27, P149 CHANG KT, 1979, J AM CHEM SOC, V101, P5082 CHAPMAN OL, 1976, J AM CHEM SOC, V98, P7844 CRISTY SS, 1970, INT J MASS SPECTROM, V5, P319 ENGEL PS, 1980, CHEM REV, V80, P99 ENGELBRECHT WJ, 1975, J S AFR CHEM I, V28, P144 ENGELBRECHT WJ, 1975, J S AFR CHEM I, V28, P148 ENGELBRECHT WJ, 1975, J S AFR CHEM I, V28, P158 ERNI B, 1980, J AM CHEM SOC, V102, P3888 FIGUERA JM, 1978, J CHEM SOC F1, P809 FRANICH RA, 1972, J CHEM SOC P1, P2034 FREY HM, 1962, J AM CHEM SOC, V84, P2647 FREY HM, 1962, J CHEM SOC, P3865 FREY HM, 1962, P CHEM SOC, P79 FREY HM, 1964, J CHEM SOC, P4700 FREY HM, 1965, J CHEM SOC, P1700 FREY HM, 1965, J CHEM SOC, P3101 FREY HM, 1966, ADV PHOTOCHEM, V4, P225 FREY HM, 1966, J CHEM SOC A, P968 FREY HM, 1970, J CHEM SOC A, P1916 FREY HM, 1977, J CHEM SOC F1, P2010 GRAHAM WH, 1965, J AM CHEM SOC, V87, P4396 GRILLER D, UNPUB JENNINGS BM, 1976, J AM CHEM SOC, V98, P6416 JONES M, 1973, CARBENE, V1 JONES WE, 1976, J PHOTOCHEM, V5, P311 KIRMSE W, 1971, CARBENE CHEM LELEU MJ, 1978, CAHIERS NOTES DOCUME, V93, P569 LIU MTH, UNPUB LIU MTH, 1972, CAN J CHEM, V50, P3009 LIU MTH, 1972, INT J CHEM KINET, V4, P229 LIU MTH, 1972, J PHYS CHEM-US, V76, P797 LIU MTH, 1973, CAN J CHEM, V51, P2393 LIU MTH, 1974, CAN J CHEM, V52, P246 LIU MTH, 1974, CHEM ENG NEWS 0909, P3 LIU MTH, 1974, J CHEM SOC P2, P937 LIU MTH, 1977, CAN J CHEM, V55, P3596 LIU MTH, 1977, J ORG CHEM, V42, P3450 LIU MTH, 1977, TETRAHEDRON LETT, P3139 LIU MTH, 1979, CAN J CHEM, V57, P1299 LIU MTH, 1980, J PHYS CHEM-US, V84, P3184 LIU MTH, 1981, J CHEM SOC P2, P53 LOWE G, 1971, J CHEM SOC CHEM COMM, P1135 MAEDA Y, 1979, J AM CHEM SOC, V101, P837 MANSOOR AM, 1966, TETRAHEDRON LETT, P1733 MEIER H, 1977, ANGEW CHEM INT EDIT, V16, P835 MILLIGAN DE, 1964, J CHEM PHYS, V41, P1199 MITSCH RA, 1964, J HETEROCYCLIC CHEM, V1, P59 MITSCH RA, 1965, J AM CHEM SOC, V87, P758 MITSCH RA, 1966, J HETEROCYCLIC CHEM, V3, P245 MIYASHI T, 1978, J CHEM SOC CHEM COMM, P442 MOFFAT JB, 1978, CHEM DIAZONIUM DIA 1 MOORE CB, 1964, J CHEM PHYS, V41, P3504 MOSS RA, 1967, TETRAHEDRON LETT, P4905 MOSS RA, 1970, J AM CHEM SOC, V92, P6951 MOSS RA, 1978, J AM CHEM SOC, V100, P6788 MOSS RA, 1978, J CHEM SOC CHEM COMM, P775 MOSS RA, 1978, TETRAHEDRON LETT, P1935 MOSS RA, 1979, TETRAHEDRON LETT, P1277 NEUVARAND EW, 1967, J PHYS CHEM-US, V71, P1229 OVERBERGER CG, 1963, TETRAHEDRON LETT, P1405 PAULSEN SR, 1960, ANGEW CHEM, V72, P781 PIERCE L, 1962, J AM CHEM SOC, V84, P2651 SCHMITZ E, 1961, ANGEW CHEM, V73, P115 SCHMITZ E, 1961, TETRAHEDRON LETT, P612 SCHMITZ E, 1962, CHEM BER, V95, P2714 SCHMITZ E, 1967, CHEM BER, V100, P2093 SCHMITZ E, 1967, DREIRINGE ZWEI HETER SCHMITZ E, 1971, 23RD INT C PUR ALL C, V2, P283 SCHMITZ E, 1979, ADV HETEROCYCL CHEM, V24, P63 SMITH NP, 1978, TETRAHEDRON LETT, P1931 SMITH NP, 1979, J CHEM SOC P2, P213 SMITH RAG, 1975, J CHEM SOC P2, P686 SU TT, 1978, J AM CHEM SOC, V100, P1872 VOIGT E, 1975, ANGEW CHEM INT EDIT, V14, P103 VOIGT E, 1975, CHEM BER, V108, P3326; NR: 86; TC: 58; J9: CHEM SOC REV; PG: 14; GA: PJ228Source type: Electronic(1
Manganese(I)‐Catalyzed Dispersion‐Enabled C−H/C−C Activation
No full textC-H/C-C Functionalizations were achieved with the aid of a versatile manganese(I) catalyst. Thus, an organometallic manganese-catalyzed C-H activation set the stage for silver-free C-H/C-C transformations with ample substrate scope and excellent levels of chemo-, site-, and diastereo-selectivities. The robust nature of the manganese(I) catalysis regime was reflected by the first C-H/C-C functionalization on amino acids under racemization-free reaction conditions. Detailed experimental and computational mechanistic studies provided strong evidence for a facile C-H activation and a rate-determining C-C cleavage, with considerable contribution from London dispersion interactions
Dilar spectabilis Zhang, Liu, H. Aspock & U. Aspock
No full text<i>Dilar spectabilis</i> Zhang, Liu, H. Aspöck & U. Aspöck <p> <i>Dilar spectabilis</i> Zhang, Liu, H. Aspöck & U. Aspöck, 2014a: 19. Type locality: China (Ningxia: Guyuan).</p> <p> <b>Materials examined.</b> 1♂, CHINA: Sichuan Province, Leshan, Mt. Emeishan [40°20′N, 117°08′E], 1800 m, 9.VII.1957, Mohua Cheng (CAU); 3♂, Sichuan Province, Leshan, Mt. Emeishan [40°20′N, 117°08′E], 2400–2500 m, 5.VII.2011, H. & U. Aspöck (HUAC); 3♂, CHINA: Xikang [this locality is the name of an old administrative province, comprising the present Sichuan Province and some parts of Xizang Autonomous Region], Yao Zhou (CAU).</p> <p> <b>Distribution.</b> China (Gansu, Henan, Ningxia, Shaanxi, Sichuan).</p> <p> <b>Remarks.</b> This species is recorded in southern China for the first time. The accurate collecting site of the three males from Xikang is unknown, but we estimate they were collected from Sichuan but not Xizang. The description of this species can be found in Zhang et al. (2014a) and thus there is no need to be repeatedly provided here.</p>Published as part of <i>Zhang, Wei, Liu, Xingyue, Aspöck, Horst & Aspöck, Ulrike, 2015, Revision of Chinese Dilaridae (Insecta: Neuroptera) (Part III): Species of the genus Dilar Rambur from the southern part of mainland China, pp. 451-494 in Zootaxa 3974 (4)</i> on page 486, DOI: 10.11646/zootaxa.3974.4.1, <a href="http://zenodo.org/record/236534">http://zenodo.org/record/236534</a>
Illustrations of <i>Beilschmiedia turbinata</i> Bing Liu & Y. Yang showing morphological details.
No full text<p>A, seedling; B, Flowering branch; C, flower; D, flower (front part removed); E, the first whorl perianth lobe; F, the second whorl perianth lobe; G. the first whorl stamen (adaxial view); H, the second whorl stamen (adaxial view); I, the third whorl stamen (abaxial view); J, the fourth whorl staminode (abaxial view); K, pistil showing the pubescent ovary; L, terminal bud; M, venation pattern (abaxial view); N, fruiting branch in the second year; O, a young fruit in the first year (Drawn by Y. B. Sun, A from <i>Bing Liu 1184</i>, B–M from <i>Bing Liu 1442</i>, N–O from <i>Bing Liu 1185, PE</i>).</p
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