Intermediates in the decomposition of aliphatic diazo-compounds. Part VIII. The mechanism of ether formation from diarylmethylenes and alcohols
作者:D. Bethell、A. R. Newall、D. Whittaker
DOI:10.1039/j29710000023
日期:——
The thermal decomposition of diphenyldiazomethane and its 4,4′-dichloro-, 4,4′-dimethoxy-, and 4,4′-dimethyl analogues at 85 °C in acetonitrile containing methyl and t-butyl alcohols (ca. 1M) has been studied. Kinetic studies indicate that the major reaction product, the alkyl diarylmethyl ether, is formed by attack of intermediate diarylmethylene on the alcohol. The relative reactivities of methyl and
The substitution products 3 (L=CO) and 4 (L= PMe3) react with an equimolar amount of sulfur or selenium by addition of the chalcogen to the Rh=CPh2 bond to generate the complexes [(eta5-C5H5)Rh(kappa2-ECPh2)(L)] (21-24) with thio- or selenobenzophenone as ligand. Similarly, treatment of 3 with CuCl affords the unusual 1:2 adduct [(eta5-C5H5)(CO)Rh(mu-CPh2)(CuCl)2] (25), which reacts with NaC5H5 to form
Regioselective monoalkylations of the vicinal cis-diol group in mannopyranosides using diaryldiazoalkanes-tin(II) chloride
作者:Sigthor Petursson、John M. Webber
DOI:10.1016/s0008-6215(82)80006-2
日期:1982.5
Abstract Highly regioselective monoalkylations of the cis -2,3-diol group in mannopyranosides can be achieved with diaryldiazoalkanes in the presence of catalytic amounts of tin(II) chloride. With diazo(diphenyl)methane ( 1 ), its 4,4′-dimethyl ( 2 ) and 4,4′-dichloro ( 3 ) derivatives, and 9-diazofluorene ( 5 ), methyl 4,6- O -benzylidene- α - d -mannopyranoside gave high yields of the respective
Sulphines. Part IV. Reactions of aromatic sulphines with diazoalkanes
作者:B. F. Bonini、G. Maccagnani、A. Wagenaar、L. Thijs、B. Zwanenburg
DOI:10.1039/p19720002490
日期:——
The cycloaddition reactions of aromatic sulphines, such as thiobenzophenone S-oxide and thiofluorenone S-oxide, with 2-diazopropane lead to 1,3,4-thiadiazoline 1-oxides in high yields. Diazomethane reacts more sluggishly with sulphines: only with thiofluorenone S-oxide was a cycloadduct obtained. The structure of the cycloadducts has been proven by photochemical extrustion of sulphur monoxide from