摘要:

AbstractAlthough the nucleophilicity/basicity at the phosphorus atom of the tetraphosphacubane2is reduced, apparently owing to the participation of the lone pairs of electrons in the P/C σ bonds, stepwise oxidation of the phosphorus atoms with bis(trimethylsilyl) peroxide or sulfur (in the presence of triethylamine) can be realized until all four phosphorus atoms have reacted to give products10–17. When2was treated with a large excess of selenium at 110°C, only the triselenide18was obtai

ISSN:1042-7163    

DOI:10.1002/hc.520060104

出版商:VCH Publishers, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe N‐alkyl‐C‐polyfluoroalkyl‐C‐chlorosulfinimides RFC(Cl)SNR have been investigated. Some aspects of their thermal stability and their [3 + 2] and [3 + 1]cycloaddition reactions hav

ISSN:1042-7163    

DOI:10.1002/hc.520060105

出版商:VCH Publishers, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractPalladium‐catalyzed hydrosilylation of silyl‐substituted butadienes1and2with MeSiCl2H has been investigated. Both steric effects and the presence of an aryl substituent affect the regiochemistry of the hydrosilylation reaction. Hydrosilylation of siloxanetethered bis‐dienes9exhibits high regio‐ and diastereosele

ISSN:1042-7163    

DOI:10.1002/hc.520060106

出版商:VCH Publishers, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractPentafluorophenyl phenyl telluride (1) and 3,5‐dichloro‐2,4,6‐trifluorophenyl phenyl telluride (2) react with pentafluorophenyllithium or 3,5‐dichloro‐2,4,6‐trifluorophenyllithium in THF at low temperatures to form the corresponding tellurium ate complexes (A) and (B) as sole intermediates in the ligand exchange on the hypervalent tellurium atom. The corresponding selenides (3) and (4) also react with identical aryllithium reagents in THF to form the discrete intermediates, selenium ate complexes (C) and (D), in the exchange reactions. In these ligand exchange reactions of tellurides and selenides, electron‐withdrawing ligands occupy the apical positions and the exchange takes place between these apical‐oriented groups. The low‐temperature1H,13C,77Se, and125Te NMR spectroscopic techniques are effective methods for detection of unstable tellurium and selen

ISSN:1042-7163    

DOI:10.1002/hc.520060107

出版商:VCH Publishers, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe He I and He II photoelectron spectra of 4‐methylmorpholine, 4‐morpholinecarbonitrile, and 4‐morpholinepropionitrile have been measured. The electronic structure and heteroatom lone pair interactions, in particular, were analyzed with the aid of HeII/HeI intensity variations, comparison with the spectra of related compounds, and AM1 semiempirical calculations. We present an example of combined inductive and resonance interactions operating in the morpholine ring s

ISSN:1042-7163    

DOI:10.1002/hc.520060108

出版商:VCH Publishers, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractUnsymmetrical diphosphenes carrying bulky aryl and phenoxy groups were prepared by the reaction of lithium 2,4,6‐tri‐t‐butylphenylphosphide with the corresponding phenyl phosphorodichloridites, followed by the dehydrochlorination reaction with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene. The diphosphenes were isolated as stable compounds. The reactions of these diphosphenes with elemental sulfur or selenium afforded the corresponding thiadiphosphiranes or selenadiphosphiranes, respectively. The diphosphenes also reacted with dichlorocarbene to give dichlorodip

ISSN:1042-7163    

DOI:10.1002/hc.520060109

出版商:VCH Publishers, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractCompounds [(Ph3P)2AgS2CSR (R = But, TIPT(2,4,6‐triisopropylthiophenolato))], formed by inserting CS2into the Ag–S bond in AgSR in the presence of PPh3, react with CH2I2to give pale yellow crystals of (Ag5I6)n(Ph3PCH2I)n, which consist of the polymeric anion (Ag5I6)n−and the cation (Ph3PCH2)+. The polyanion (Ag5I6)n−is composed of alternate I5‐pentagons and Ag5‐pentagons that are connected by Ag–I bonds along the C axis to form a layered “pagoda” structure, in which there exists an unusual stereochemistry of iodine. Crystal data: monoclinic, space group P21/c, a = 15.004(12) Å, b = 27.19(2) Å, c = 7.898 Å, β = 97.18(5)°, V = 3205(4) Å3, Z = 4, R = 0.0673 for 27

ISSN:1042-7163    

DOI:10.1002/hc.520060110

出版商:VCH Publishers, Inc.    

年代:1995

数据来源: WILEY

摘要:

Abstract2‐Chloro and 2‐phenoxy substituted 1,1‐bis(diethylamino)ethylenes (4aand4c) react with elemental sulfur at room temperature to give the inner salt, bis(diethylamino)carbeniumdithiocarboxylate (1a), in excellent yields with extrusion of hydrogen chloride and phenol, respectively, thus providing a new and convenient synthesis of the structurally interesting inner salt. X‐ray single crystal structure analysis of1areveals that the NCN and SCS planes are nearly vertical to each other with a dihedral angle of 82.0° and that the positive and negative charges are delocalized over the NCN and SCS moieties, respectively. Results of solid‐state13C NMR of1a

ISSN:1042-7163    

DOI:10.1002/hc.520060111

出版商:VCH Publishers, Inc.    

年代:1995

数据来源: WILEY

摘要:

Abstract2,3‐Dihydro‐2,2,4‐trimethylthieno[3,2‐b]pyridinium 1‐oxide iodide (1) has been reacted with various inorganic and organic hydride donors. It has been found that the stereochemistry of reaction is controlled by the orientation of the sulfinyl dipole, and the relative bulkiness of substituents plays no role in determining the reaction face: a reactive hydride donor prefers to attack at the anti‐face with respect to the sulfinyl dipole, whereas a less reactive hydride donor prefers to attack at t

ISSN:1042-7163    

DOI:10.1002/hc.520060112

出版商:VCH Publishers, Inc.    

年代:1995

数据来源: WILEY

摘要:

AbstractComplexation of lanthanoid metal ions with 1,2‐bis(o‐aminophenoxy)‐ethane‐N,N,N′,N′‐tetraacetic acid and its two derivatives, in which the distance between the chelating functions is changed, has been studied by potentiometric pH titration. There are two complexation modes depending on the size of the metal ion. Structural flexibility of the chelator accounts for the change in the comp

ISSN:1042-7163    

DOI:10.1002/hc.520060113

出版商:VCH Publishers, Inc.    

年代:1995

数据来源: WILEY