Wiechang Jin - Academia.edu (original) (raw)
Papers by Wiechang Jin
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Organometallics, Jul 25, 2001
ABSTRACT
Angewandte Chemie, Jun 20, 2005
General. GC analyses of cyclopropanation reactions were carried out on Hewlett Packard 5890A and ... more General. GC analyses of cyclopropanation reactions were carried out on Hewlett Packard 5890A and 6890 gas chromatographs equipped with FID detectors. For the determination of the trans:cis ratio of the cyclopropanes, a 30-m HP-5 capillary column with 0.32-mm inner diameter and 0.25-mm film thickness was used. For GC determination of enantiomeric excess, Supelco β-DEX series (120 and 225) chiral columns were used and for HPLC determina tion of enantiomeric excess, a Pirkle Covalent (S,S) Whelk-O 1 purchased from Regis Technologies was used. The calibration curve for yield determination of the product styrene cyclopropanation, 2-phenyl cyclopropane carboxylic acid ethyl ester, was produc ed using an analytically pure sample. [1] 1 H NMR spectra were recorded on an Inova-500 FT-NMR spectrometer (499.733 MHz) and are reported as follows: chemical shift (multiplicity (b = broad, s = singlet, d = doublet, t = triplet, q = quartet, and m = multiplet), and integration). Chemical shifts for 1 H NMR spectra are reported in ppm downfield from tetramethylsilane (TMS, δ scale) using residual solvent signals in the deuterated solvents as references. 31 P NMR spectra were recorded on a Mercury-400 FT-NMR spectrometer (161.898 MHz) and chemical shifts are reported in ppm downfield of an external H 3 PO 4 standard. Catalysts 1-2 were synthesized and characterized by methods previously reported by our laboratory. [1] Diamino-N,N'-bis(3,5-di-tert-butylsalicylidene) salen ligands were prepared from the condensation of 3,5-di-tert-butyl salicyladehyde with the corresponding diamines. [RuCl 2 (pcymene)] 2 [2] and sulfoxides 9 [3] , 10 [3] , and 11 [4] were all prepared according to literature procedures. Dichloromethane was distilled over calcium hydride; tetrahydrofuran (THF), toluene, and hexane were distilled over sodium/benzophenone. All solvents were distilled under nitrogen and saturated with nitrogen prior to use. All olefins were purchased from Aldrich Chemical Company, dried over calcium hydride, vacuum distilled, and stored at 0 ºC under nitrogen prior to use. Ethyl diazoacetate (EDA, 91% in CH 2 Cl 2) was purchased from Aldrich and degassed via three freeze-pump-thaw cycles before used. Deuterated solvents were purchased from Cambridge Isotope Laboratories, distilled over calcium hydride, and vacuum transferred into an airtight solvent bulb prior to transfer into the inert-atmosphere glovebox. All other reagents were purchased from Aldrich Chemical Company and used without further purification unless otherwise noted. All reactions were carried out either under a dry nitrogen atmosphere using standard Schlenk techniques or in an inert-atmosphere glovebox unless otherwise noted. Synthesis of Bis(triphenylphosphine)-1,2-ethanediamino-N,N'-bis(3,5-di-tertbutylsalicylidene)ruthenium(II) (3). This compound was prepared by modifying a literature
Bulletin of The Korean Chemical Society, 1991
Angewandte Chemie, Aug 16, 2002
Bulletin of The Korean Chemical Society, 1989
The NMR shifts of a series of para-substituted 9-aryl-tricyclonon-9-yl and 8-aryl-tetracyclo-oct-... more The NMR shifts of a series of para-substituted 9-aryl-tricyclonon-9-yl and 8-aryl-tetracyclo-oct-8-yl cations were measured in in order to examine whether the values can be used to explain the mechanism for the stabilization of the geometrically rigid cyclopropylcarbinyl cations. Plots of the shifts against reveal excellent linear correlation. The tricyclononyl systems yield a value of -4.95 with a correlation coefficient r = 0.9948. The tetracyclo-octanyl systems give a value of -6.39 with r = 0.9943. A fair parallelism exists between the results of nmr studies and the change of values in these cations. Accordingly, the present study established that the value can be used as a mearsure of the geometric influence for the charge delocalization in cyclopropylcarbinyl cations.
Angewandte Chemie, Sep 17, 2001
Chiral phosphine ligands are central to many developments in transition metal catalyzed enantiose... more Chiral phosphine ligands are central to many developments in transition metal catalyzed enantioselective transformations.1 Recent demonstrations of high enantioselectivity for a wide range of hydrogenation reactions with Rh complexes of DuPHOS,2 PennPHOS,3 RoPHOS,4 BASPHOS,5 ...
Journal of the American Chemical Society, Nov 1, 1995
Among the isolable carbon monoxide adducts of coinage metals, the silver carbonyls represent the ... more Among the isolable carbon monoxide adducts of coinage metals, the silver carbonyls represent the most recently reported group.'-4 Structurally characterized silver carbonyl complexes are extremely rare, and the only examples in the literature include [Ag(CO)I[B(OTeFj)4] and [Ag(CO)21[B(OTeFj)41.5-6 purchase the Siemens P4 single crystal X-ray diffractometer. The C,H,N analyzer was purchased through a grant from the Defense Advanced Research Projects Agency, monitored by the Office of Naval Research. We thank Professor P. S. Braterman (UNT) for helpful discussions. Supporting Information Available: Solution and solid state IR spectra for 1, tables of crystallographic data, atomic coordinates, thermal parameters, and complete bond distances and angles for 1 and 2 (23 pages). This material is contained in many libraries on microfiche, immediately follows this article in the microfilm version of the journal, can be ordered from ACS, and can be downloaded from the Intemet; see any current masthead page for ordering information and Internet access instructions. JA95 1680M (38) Orpen, A.
ChemInform, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform 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.
Zeitschrift für anorganische und allgemeine Chemie, Feb 11, 2020
New monoanionic CNC pincer ligands, [N{SiMe2CH2(RIm)}2]– (R = tBu, iPr, Ph) featuring three diffe... more New monoanionic CNC pincer ligands, [N{SiMe2CH2(RIm)}2]– (R = tBu, iPr, Ph) featuring three different N‐heterocyclic carbenes and a disilylamido moiety is reported. Treatment of the lithium salt of [N{SiMe2CH2(RIm)}2]– with CuIOTf afforded the corresponding copper complexes [N{SiMe2CH2(RIm)}2]Cu in 41–56 % yield. X‐ray crystal structures of [N{SiMe2CH2(RIm)}2]Cu show that they are monomeric and feature three‐coordinate, pseudo T‐shaped copper(I) sites. The X‐ray crystal structure of one of the precursor lithium complexes, [N{SiMe2CH2(tBuIm)}2]Li is also presented.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Organometallics, Jul 25, 2001
ABSTRACT
Angewandte Chemie, Jun 20, 2005
General. GC analyses of cyclopropanation reactions were carried out on Hewlett Packard 5890A and ... more General. GC analyses of cyclopropanation reactions were carried out on Hewlett Packard 5890A and 6890 gas chromatographs equipped with FID detectors. For the determination of the trans:cis ratio of the cyclopropanes, a 30-m HP-5 capillary column with 0.32-mm inner diameter and 0.25-mm film thickness was used. For GC determination of enantiomeric excess, Supelco β-DEX series (120 and 225) chiral columns were used and for HPLC determina tion of enantiomeric excess, a Pirkle Covalent (S,S) Whelk-O 1 purchased from Regis Technologies was used. The calibration curve for yield determination of the product styrene cyclopropanation, 2-phenyl cyclopropane carboxylic acid ethyl ester, was produc ed using an analytically pure sample. [1] 1 H NMR spectra were recorded on an Inova-500 FT-NMR spectrometer (499.733 MHz) and are reported as follows: chemical shift (multiplicity (b = broad, s = singlet, d = doublet, t = triplet, q = quartet, and m = multiplet), and integration). Chemical shifts for 1 H NMR spectra are reported in ppm downfield from tetramethylsilane (TMS, δ scale) using residual solvent signals in the deuterated solvents as references. 31 P NMR spectra were recorded on a Mercury-400 FT-NMR spectrometer (161.898 MHz) and chemical shifts are reported in ppm downfield of an external H 3 PO 4 standard. Catalysts 1-2 were synthesized and characterized by methods previously reported by our laboratory. [1] Diamino-N,N'-bis(3,5-di-tert-butylsalicylidene) salen ligands were prepared from the condensation of 3,5-di-tert-butyl salicyladehyde with the corresponding diamines. [RuCl 2 (pcymene)] 2 [2] and sulfoxides 9 [3] , 10 [3] , and 11 [4] were all prepared according to literature procedures. Dichloromethane was distilled over calcium hydride; tetrahydrofuran (THF), toluene, and hexane were distilled over sodium/benzophenone. All solvents were distilled under nitrogen and saturated with nitrogen prior to use. All olefins were purchased from Aldrich Chemical Company, dried over calcium hydride, vacuum distilled, and stored at 0 ºC under nitrogen prior to use. Ethyl diazoacetate (EDA, 91% in CH 2 Cl 2) was purchased from Aldrich and degassed via three freeze-pump-thaw cycles before used. Deuterated solvents were purchased from Cambridge Isotope Laboratories, distilled over calcium hydride, and vacuum transferred into an airtight solvent bulb prior to transfer into the inert-atmosphere glovebox. All other reagents were purchased from Aldrich Chemical Company and used without further purification unless otherwise noted. All reactions were carried out either under a dry nitrogen atmosphere using standard Schlenk techniques or in an inert-atmosphere glovebox unless otherwise noted. Synthesis of Bis(triphenylphosphine)-1,2-ethanediamino-N,N'-bis(3,5-di-tertbutylsalicylidene)ruthenium(II) (3). This compound was prepared by modifying a literature
Bulletin of The Korean Chemical Society, 1991
Angewandte Chemie, Aug 16, 2002
Bulletin of The Korean Chemical Society, 1989
The NMR shifts of a series of para-substituted 9-aryl-tricyclonon-9-yl and 8-aryl-tetracyclo-oct-... more The NMR shifts of a series of para-substituted 9-aryl-tricyclonon-9-yl and 8-aryl-tetracyclo-oct-8-yl cations were measured in in order to examine whether the values can be used to explain the mechanism for the stabilization of the geometrically rigid cyclopropylcarbinyl cations. Plots of the shifts against reveal excellent linear correlation. The tricyclononyl systems yield a value of -4.95 with a correlation coefficient r = 0.9948. The tetracyclo-octanyl systems give a value of -6.39 with r = 0.9943. A fair parallelism exists between the results of nmr studies and the change of values in these cations. Accordingly, the present study established that the value can be used as a mearsure of the geometric influence for the charge delocalization in cyclopropylcarbinyl cations.
Angewandte Chemie, Sep 17, 2001
Chiral phosphine ligands are central to many developments in transition metal catalyzed enantiose... more Chiral phosphine ligands are central to many developments in transition metal catalyzed enantioselective transformations.1 Recent demonstrations of high enantioselectivity for a wide range of hydrogenation reactions with Rh complexes of DuPHOS,2 PennPHOS,3 RoPHOS,4 BASPHOS,5 ...
Journal of the American Chemical Society, Nov 1, 1995
Among the isolable carbon monoxide adducts of coinage metals, the silver carbonyls represent the ... more Among the isolable carbon monoxide adducts of coinage metals, the silver carbonyls represent the most recently reported group.'-4 Structurally characterized silver carbonyl complexes are extremely rare, and the only examples in the literature include [Ag(CO)I[B(OTeFj)4] and [Ag(CO)21[B(OTeFj)41.5-6 purchase the Siemens P4 single crystal X-ray diffractometer. The C,H,N analyzer was purchased through a grant from the Defense Advanced Research Projects Agency, monitored by the Office of Naval Research. We thank Professor P. S. Braterman (UNT) for helpful discussions. Supporting Information Available: Solution and solid state IR spectra for 1, tables of crystallographic data, atomic coordinates, thermal parameters, and complete bond distances and angles for 1 and 2 (23 pages). This material is contained in many libraries on microfiche, immediately follows this article in the microfilm version of the journal, can be ordered from ACS, and can be downloaded from the Intemet; see any current masthead page for ordering information and Internet access instructions. JA95 1680M (38) Orpen, A.
ChemInform, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform 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.
Zeitschrift für anorganische und allgemeine Chemie, Feb 11, 2020
New monoanionic CNC pincer ligands, [N{SiMe2CH2(RIm)}2]– (R = tBu, iPr, Ph) featuring three diffe... more New monoanionic CNC pincer ligands, [N{SiMe2CH2(RIm)}2]– (R = tBu, iPr, Ph) featuring three different N‐heterocyclic carbenes and a disilylamido moiety is reported. Treatment of the lithium salt of [N{SiMe2CH2(RIm)}2]– with CuIOTf afforded the corresponding copper complexes [N{SiMe2CH2(RIm)}2]Cu in 41–56 % yield. X‐ray crystal structures of [N{SiMe2CH2(RIm)}2]Cu show that they are monomeric and feature three‐coordinate, pseudo T‐shaped copper(I) sites. The X‐ray crystal structure of one of the precursor lithium complexes, [N{SiMe2CH2(tBuIm)}2]Li is also presented.