Synthesis of polyunsaturated constituents of phenolic lipids
摘要:
The diene, (ZZ)-[(8,11)-pentadecadienyl]salicylic acid, (or 2-hydroxy-6-[(ZZ)-pentadeca-8,11-dienyl]benzoic acid), has been synthesised by two routes. In the first, the key intermediate methyl or ethyl 2-hydroxy-6-(7-bromoheptyl)benzoate has been converted to methyl or ethyl 2-hydroxy-6-(10-hydroxydec-8-ynyl)benzoate and thence by reaction of the corresponding bromide with 1-pentynylmagnesium bromide to methyl or ethyl 2-hydroxy-6-(pentadeca-8,11-dienyl)benzoate. Selective reduction afforded methyl or ethyl 2-hydroxy-6-[(ZZ)-pentadeca-8,11-dienyl]benzoate. An attempt to employ the Grignard reagent from methyl 2-methoxy-6-(non-8-ynyl)benzoate and reaction with 1-bromohex-2-yne was ineffective because of a side reaction of the former with ethylmagnesium bromide to give a ketone. In the third approach ethyl 2-methoxy-6-methylbenzoate was alkylated with 1-iodotetradeca-7,10-diyne and the product selectively reduced as before to the O-methyl ether ethyl ester. A variety of C-14 intermediates has been prepared for the derivation of the 8(E), 11(E), 8(E), 11(Z) and 8(2), 11(E) stereoisomers by the alkylation procedure. A similar methodology of alkylation can be adopted for obtaining corresponding trienes in which some progress has been made commencing with the synthesis of the 8(2),11(2),14 compound. (C) 1997 Elsevier Science Ireland Ltd.
amido tert-butylimido-vanadium(V) complexes as well as of the binuclear complexes [μ-NtBu)2V2(NtBu)2Cl2] and [(μ-0)V2(NtBu)2Cp2Cl2] are also described. All compounds obtained have been characterized by 51V NMR spectroscopy. tBuN=V(OMe)3 was investigated by X-ray diffraction analysis; the molecular structure has been found to be that of a binuclear vanadium(V) complex with two bridging methoxo ligands.
Nucleophilic Substitution of η<sup>5</sup>-Pyrrolyl Ligands in Ruthenium(II) Complexes
作者:M. Rakowski DuBois、K. G. Parker、C. Ohman、B. C. Noll
DOI:10.1021/om9700268
日期:1997.5.1
pyrrolyl ligand has been characterized in some cases, and protonation of the substituted pyrrole complex led to isolation of the free substituted pyrrole with recycling of the rutheniumcomplex. The nucleophilic substitutions are sensitive to the electronic features of the supporting ligands in the complex and to the strength of the nucleophiles.
的RuCl的反应2(PPH 3)3与所述吡咯基复合物(NC的形成pyrrolyllithium结果4 ħ 4)的RuCl(PPH 3)2,1,已特征在于X射线衍射研究。结构确认η 5为吡咯配体η-键接模式。配体取代反应1导致相关η的简便合成5吡咯基钌络合物与其它suppporting配体。PET的反应3衍生物(NC 4 H ^ 4)RUX(PET 3)如图2所示,X = Cl和I,用芳基锂和烷基锂试剂导致吡咯基配体的亲核取代,同时氢转移到金属离子上,形成(2-RNC 4 H 3)RuH(PEt 3)2。可以在氯化溶剂中将氢化物产物转化为相应的氯化物衍生物,以及络合物(2-PhNC 4 H 3)RuCl(PEt 3)2已经在结构上得到了表征。在某些情况下,已经表征了在配位的吡咯基配体上的第二次亲核取代反应,并且取代的吡咯配合物的质子化导致游离取代的吡咯的分离以及钌配合物的再循环。亲核取代对复
Synthesis and physicochemical characteristics of alkane (or arene)-thio-, -sulphinato-, and -sulphonato-indium(III) porphyrins. Crystal structure of methanesulphonato(5,10,15,20-tetraphenylporphyrinato)indium(III)
作者:Panayotis Cocolios、Pierre Fournari、Roger Guilard、Claude Lecomte、Jean Protas、Jean C. Boubel
DOI:10.1039/dt9800002081
日期:——
Indium(III) porphyrins containing metal–sulphur bonds [InL(SR)](L = porphyrinate, R = alkyl or aryl) are reported. The photochemical oxidation of these leads to the corresponding sulphinatoindium(III) porphyrins [InL(SO2R)]. The insertion of sulphur dioxide between the indium atom and the alkyl or aryl group of [InL(R)] also gives rise to the sulphinato-compounds. The latter can easily be oxidised
Magnesium bromide radicals have to be prepared as high‐temperature molecules and trapped as a metastable solution because a seemingly simple reduction of donor‐free Grignardcompounds failed. However, the essential role of magnesium(I) species during the formation of Grignardcompounds could be demonstrated experimentally.
Synthesis of tert-butyl mercapto complexes of titanium(IV). X-ray crystal structure of Ti(diars)Cl2 (tBuS)2
作者:Richard A. Jones、Stuart T. Schwab、Bruce R. Whittlesey
DOI:10.1016/s0277-5387(00)84527-1
日期:1984.1
tert-butyl mercapto compounds, Ti(L)Cl2(tBuS)2 (L = diars, dmpe, dppe), has been synthesized and characterized. The X-raycrystalstructure of Ti(diars)Cl2(tBuS)2 (1) shows that the Ti(IV) atom has a distorted octahedral geometry with trans chlorides and cis tert-butyl mercapto units. The structures of the other complexes are similar based on spectroscopic (NMR, IR) evidence. Crystal data for (1): C18H34As2Cl2S2Ti