摘要:

AbstractEthyl and phenyl chlorodithioformate have been reacted at −20°C with phenylmagnesium bromide andp‐tolylmagnesium bromide to give substituted thioketones4in acceptable yields. The reaction between methyl chlorodithioformate and methylmagnesium iodide at −40°C gave dimethyl trithiocarbonate and 3,3,7,7‐tetrakis(methylthio)‐1,2,4,6‐tetrathiepane‐5‐thione (8). When the reaction took place at 0°C other compounds also were isolat

ISSN:0165-0513    

DOI:10.1002/recl.19750940103

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractGraphs depicting the interrelations of unsaturated systems (eliminations, additions, substitutions and isomerizations) are presented.Such graphs are suitable frameworks for interrelation studies, especially for tele reactions (a large group of reactions occurring at the ends of conjugated systems and involving only a change of hybridization of the terminal atoms).

ISSN:0165-0513    

DOI:10.1002/recl.19750940104

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe reactions between 1,1‐bis(p‐dimethylaminophenyl)ethylene (Michler's ethylene) (5) and salicylaldehydes (6) were studied for the purpose of synthesizing photochromic chromenes (1). Although we proved the presence of the chromene1under some conditions, the only compounds we could isolate were the so‐called “disubstitution products”7. Reaction of 2,2‐bis[p‐(dimethylamino)‐phenyl]‐2H‐chromene[1a, synthesized by a Grignard reaction of coumarin withp‐(dimethylamino)‐phenylmagnesium bromide] with Michler's ethylene also gives the “disubstitution product”7a. Reactions of Michler's ethylene with 2,2‐bis(p‐methoxyphenyl)‐2H‐chromene (3) and the spiropyran11furnished the “mixed disubstitution products”9and10, respectively. A reaction of the latter with 5‐nitrosalicylaldehyde gives 2,2‐bis[p‐(dimethylamino)phenyl]‐6‐nitro‐2H‐chromene1b. The photochrom

ISSN:0165-0513    

DOI:10.1002/recl.19750940105

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractC‐Sulfonylformamidrazones are formed as isolable adducts from sulfonyl cyanides and the α‐effect nucleophiles hydrazine and phenylhydrazine. The adducts react with triethyl orthoformate or orthoacetate to give 1,2,4‐tri

ISSN:0165-0513    

DOI:10.1002/recl.19750940106

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

Abstract1‐Alkynyl sulfones R1CCSO2‐R2,1are very prone to addition of organo‐copper(I) reagents “RCu”. The stereochemistry in the vinylic sulfones RR1CCHSO2‐R2,2so produced appeared to be dependent on the relative amounts of copper(I) bromide and the Grignard RMgX (X = Cl, Br) from which the organocopper(I) compound “RCu” was prepared. When an excess of copper(I) bromide was used the addition proved to be almost exclusively acis

ISSN:0165-0513    

DOI:10.1002/recl.19750940107

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractPhotolysis of 2,4,6‐trimethylpyrimidine 1‐oxide in methanol with light of 254 nm leads to rearrangement into 4(5)‐acetyl‐2,5(4)‐dimethylimidazole and 1,2,4‐trimethyl‐1,6‐dihydro‐6‐oxopyrimidine. In benzene only the formation of the imidazole and an unknown compound X is observed. In both solvents the products are formed from the same primary photoproduct. Ring contraction into an imidazole also takes place on ultraviolet irradiation of 4‐chloro‐2,6‐dimethylpyrimidine 1‐oxide in benzene and of 2,6‐dimethyl‐4‐methoxypyrimidine 1‐oxide in methanol. Results of conventional flash photolysis applied with the aim of getting some information about the intermediary formation of oxaziridines are inconclusive. The role of possible intermediates ‐ oxaziridines, 1,2,4‐oxadiazepines or zwitter ionic species ‐ in t

ISSN:0165-0513    

DOI:10.1002/recl.19750940108

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe trialkylgermylamines R3GeNR′2, condense by 1‐2 dipolar addition on to one of the carbonyl groups of α‐diketones, such as biacetyl or benzil, leading to α‐amino β‐oxoalkoxygermanes. Dialkylbis(dimethylamino)germanes, R2Ge(NR′2)2also, lead to an insertion derivative on to one of the carbonyl groups of biacetyl or benzil, but the expected 4,5‐bis(dimethylamino)‐2‐germa‐1, 3‐dioxolane is not obtained.All the α‐amino β‐oxoalkoxygermanes formed in the course of these reactions are thermally unstable. The decomposition proceeds by an intermolecular mechanism, observed previously for α‐amino β‐oxoalkoxygermanes and leads, in the case of amine R3GeNR′2to an α‐ketoenamine and in the case of R2Ge(NR′2)2to a diaminodiene.In the reaction between acetylacetone and (triethylgermyl)dimethylamine, without a solvent, only 1,2 dipolar addition on one of the carbonyl groups of the reagent is observed, to the exclusion of cleavage of the Ge‐N bond. In the same reaction carried out in hexane, Ge‐N bond cleavage by the enolic form of acetylacetone is observed; nevertheless, the formation of a 1‐2 addition derivative on to the carbonyl group still preponderates.The α‐amino β‐oxoalkoxygermanes formed are thermally unstable and the decomposition by an intramolecular mechanism proceeds by coordination between oxygen of the Ge‐O‐C group an

ISSN:0165-0513    

DOI:10.1002/recl.19750940109

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe action of diethyl malonate and ethyl cyanoacetate on dimethyl(triethylgermyl)amine has been studied. In both cases, competition between two reactions is observed: a cleavage reaction of the germanium‐nitrogen bond by these reagents and an addition reaction on to the carbonyl group of an ester function.The cleavage reaction of the Ge‐N bond leads to the corresponding β‐functionalC‐germanium derivatives: ethylC‐(triethylgermyl)malonate and ethylC‐(triethylgermyl)cyanoacetate, thermally stable.The addition reactions on the carbonyl group of ester functions lead to new thermally unstable β‐functional α‐aminoalkoxygermanes. These last reactions are compared with those obtained with ethyl acetate or ethylenic esters.The thermal decomposition of β‐functional α‐aminoalkoxygermanes formed in the course of these reactions has been studied, and leads mainly to alkoxygermanes and the corresponding β‐functional amide by an intramole

ISSN:0165-0513    

DOI:10.1002/recl.19750940110

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe synthesis and characterization of some chloro‐bridged platinum(II) complexes [Pt2Cl4L2], where L = 3,3‐dimethyl‐1‐butene, 3,3‐dimethyl‐1‐pentene, 3,3‐dimethyl‐1‐hexene or partially deuterated 3,3‐dimethyl‐1‐pentene is described. Complexation of these alkenes produces asymmetry within the molecule, which can be seen in the1H NMR spectra of the complexes. The coordinated alkenes undergo exchange with free alkene in solution. The kinetics of this exchange in benzene and chloroform are reported. It has been found that alkene exchange in these complexes is preceded by a rapid dedimerizati

ISSN:0165-0513    

DOI:10.1002/recl.19750940111

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe origin of the products of the ammoxidation of propene over cerium‐doped silica supported bismuth molybdates was derived from the effects of temperature (380°‐480°C) on overall conversion and selectivity in fixed‐bed operations. At low (<80 %) conversion levels, the ammoxidation reaction leads to acrylonitrile at Mo(VI) active sites and to by‐products (HCN, acetonitrile, CO and CO2) at Mo(V) sites; at the highest conversions, by‐products derive from consecutive oxidation of ac

ISSN:0165-0513    

DOI:10.1002/recl.19750940112

出版商:WILEY‐VCH Verlag    

年代:1975

数据来源: WILEY