摘要:

A series of cobalt(II), copper(II), and zinc(II) complexes of the title ligand are reported. 1:1 complexes of cobalt and zinc, M(OBT)X2(M = Co, Zn; X = Cl, Br, I, NCS), have four-coordinate pseudo-tetrahedral stereochemistries while for copper (X = Cl, Br), distorted square geometries are suggested. Six-coordinate 1:1 derivatives are also obtained for cobalt and copper, M(OBT)(NO3)2(M = Co, Cu), while the 1:2 derivative Cu(OBT)2(ClO4)2-2H2O may be square planar. OBT appears to coordinate as an N2donor in all cases. Preliminary X-ray data confirm a distorted square CuN2Cl2structure for the copper chloride complex. Hydrogen bonded chloroform solvate molecules appear to be present in three cobalt complexes (X = Cl, Br, NCS).

ISSN:0008-4042    

DOI:10.1139/v79-001

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Bis(acetylacetonato)copper(II) was sensitized by some ketones with a wide range of triplet energies to undergo photodecomposition to give the same products as that obtained in the direct photolysis but with much better efficiency. Other sensitizers such as fluorenone and aromatic hydrocarbons failed to sensitize the reaction. There exists no correlation of the sensitizer triplet energies with the sensitization results. This, and rapid quenching processes, indicated that the classical energy transfer process was unlikely. The sensitization process by an electron transfer within an encounter complex was proposed to explain the decomposition of Cu(acac)2; the calculated free energy changes (ΔG) associated with the electron transfer from the available data support the proposal. Chemical reactions of excited state anthracene and 1-cyanonaphthalene with Cu(acac)2may also occur. Irradiation of Cu(acac)2in the presence of triphenylphosphine and benzophenone led to an excellent yield of Cu(acac)(PPh3)2without causing precipitation of copper(I) complexes.

ISSN:0008-4042    

DOI:10.1139/v79-002

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

ω-CyanoN,N-disubstituted amides are conveniently prepared from halogenated amides by treatment with alkaline cyanides. By reacting them with powerful bases such as lithium dialkylamides in ether, these cyano amides may be metallated in α position to the cyano group only. When they are warmed up, the anions react with the amide group to afford α-cyano cyclanones by an intramolecular cyclisation.

ISSN:0008-4042    

DOI:10.1139/v79-003

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

13C chemical shifts and13C–31P couplings are reported for 11 cyclic phosphoramidates of ring sizes from four to nine. Vicinal couplings are compared with those of carbocyclic analogs and provide insight regarding the degree of nitrogen lone pair derealization into the N—P bond. For six-membered and larger rings, there appears to be nearly complete lone pair delocalization, i.e., a trigonal planar nitrogen atom. In azetidine derivatives the nitrogen lone pair remains localized, giving rise to a highly puckered ring conformation. Pyrrolidine derivatives are viewed as having a nitrogen with a partially delocalized electron pair.

ISSN:0008-4042    

DOI:10.1139/v79-004

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

13C and1H nmr spectra were obtained and assigned for nine C-19 substituted cholest-5-enes, three 6β-substituted 19-norcholest-5(10)-enes, and several related steroids.13C chemical shift effects have previously not been studied in either C-19 substituted steroids or in cholest-5(10)-enes. In the present study, substituent effects on the13C chemical shifts of the α, β, γ, and δ carbons were evaluated in detail. Although the substituent in C-19 substituted and 6β-methyl substituted steroids is less rigidly oriented with respect to the rest of the molecule than in ring-substituted steroids, similar shift effects were observed. In cholest-5-enes the observed13C and1H shift effects and the temperature dependence of the13C shifts indicate that the preferred orientation of the C-19 substituent isantito C-1. The relative stabilities of the rotamers can be attributed to the orientation of the C-19 substituent with respect to the double bond. This interpretation is supported by the fact that the preferred orientation of the iodine in 6β-iodomethyl-19-norcholest-5(10)-en-3β-ol has the same spacial relationship with respect to the double bond, i.e.,gaucheto C-5 and C-7.

ISSN:0008-4042    

DOI:10.1139/v79-005

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Triphenyltin lithium (1) was reacted separately with 1,2:3,5-di-O-methylene-6-O-tosyl-α-D-glucofuranose (2), with methyl 2,3-anhydro-4,6-O-benzylidene-α-D-allopyranoside (4), and with methyl 2,3-anhydro-4,6-O-benzylidene-α-D-mannopyranoside (6), to form in each case a sugar-stannane derivative having a stable carbon-tin bond. These products have been studied by1H and13C nmr spectroscopy.

ISSN:0008-4042    

DOI:10.1139/v79-006

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The preparation of dimethyl 4-(1-chloroethyl)-1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate and its reaction with nucleophilic reagents are described. Potassium cyanide, potassium succinimide, or methanolic triethylamine gave, stereospecifically, 4,5-dihydroazepines in which substituents at C(4) and C(5) aretrans, whereas potassium thiocyanate afforded only the corresponding 4-(1-thiocyanatoethyl)-1,4-dihydropyridine. Sodium hydrosulfide afforded a mixture of 8-thia-2-azabicyclo[3.2.1]oct-3-ene-4,7-diesters epimeric at C(7), whereas potassium carbonate in aqueous dimethyl sulfoxide yielded an 8-oxa-2-azabicyclo-[3.2.1]oct-3-ene-4,7-diester. The stereochemistry of these bicyclic compounds is established using nmr spectroscopy. In acid media, dimethyl 2,5,7-trimethylazepine-3,6-dicarboxylate and a 4-methoxy-4,5-dihydroazepine rearranged to give 1,4-dihydropyridine derivatives; a mechanism for this ring contraction is suggested.

ISSN:0008-4042    

DOI:10.1139/v79-007

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Alkaloid Fk-5, isolated fromF.kralikii, has been shown to be fumaritineN-oxide. The structure was established by1H and13C nmr and by mass spectrometry and confirmed by reduction of Fk-5 to fumaritine. The13C spectra of fumaritine and itsN-oxide are discussed.

ISSN:0008-4042    

DOI:10.1139/v79-008

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2has been determined by X-ray diffraction. The crystals are orthorhombic, space groupP212121, witha = 12.486(6),b = 13.444(7),c = 14.678(11) Å, andZ = 4. The structure was refined by block-diagonal least-squares analysis to a conventionalRfactor of 0.050 and a weightedRw = 0.045.The coordination around the platinum atom is square planar. Guanosine is bonded to platinum through N(7). The purine planar ring makes an angle of 62.7° with the platinum coordination plane. The structure is stabilized by hydrogen bonding.

ISSN:0008-4042    

DOI:10.1139/v79-009

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

A number of Pd(II) and Pt(II) complexes of amino acids and dipeptides have been isolated and characterized. The solution and solid-state circular dichroism of the amino acid complexes show a fairly consistent pattern, which is opposite to that shown by the dipeptide complexes. Some of the problems associated with the interpretation of the spectra in terms of spectroscopic assignment and structural features are discussed.

ISSN:0008-4042    

DOI:10.1139/v79-010

出版商:NRC Research Press    

年代:1979

数据来源: NRC