Efficient, scalable and economical preparation of tris(deuterium)- and<sup>13</sup>C-labelled<i>N</i>-methyl-<i>N</i>-nitroso-<i>p</i>-toluenesulfonamide (Diazald®) and their conversion to labelled diazomethane
作者:Samuel W. J. Shields、Jeffrey M. Manthorpe
DOI:10.1002/jlcr.3231
日期:2014.10
A method for the preparation of multi-gramme quantities of N-methyl-d3-N-nitroso-p-toluenesulfonamide (Diazald-d3) and N-methyl-13C-N-nitroso-p-toluenesulfonamide (Diazald-13C) and their conversion to diazomethane-d2 and diazomethane-13C, respectively, is presented. This approach uses robust and reliable chemistry, and critically, employs readily commercially available and inexpensive methanol as the label source. Several reactions of labelled diazomethane are also reported, including alkene cyclopropanation, phenol methylation and α-diazoketone formation, as well as deuterium scrambling in the preparation of diazomethane-d2 and subsequent methyl esterification of benzoic acid.
Inhaltsstoffe Westafrikanischer Arzneipflanzen, VIII. 3-Hydroxynornuciferin und 3-Hydroxy-6a,7-dehydronuciferin, Nebenalkaloide inHexalobus crispiflorus — Massenspektrometrische Strukturfestlegung an Noraporphinen
Bei der massenspektrometrischen Fragmentierung von 3-substituierten N-Acetylnoraporphinen tritt ein Zerfallsweg auf, der spezifisch unter Eliminierung des Substituenten an C-3 verläuft. Dieser analytisch bedeutsame Prozeß wurde näher untersucht und zur Strukturfestlegung von Neben-alkaloiden aus Hexalobus crispiflorus herangezogen.
Evidence for diazenyl allyl diradicals in the thermolysis of 4-alkylidene-1-pyrazolines
作者:Robert J. Crawford、Moon Ho Chang
DOI:10.1016/0040-4020(82)80164-6
日期:1982.1
e breaks preferentially to the syn bond. It is suggested that the product determining step involves an intramolecular radical displacement of nitrogen, as well as an electrocyclic rotation of the allylic methylene groups of the diazenyl allyl diradical, to generate the cyclopropane ring concerted with the loss of nitrogen. The position of deuterium in the methylmethylenecyclopropane can best be rationalized
Preparation of (chloromethyl)palladium(II) derivatives from complexes of palladium dichloride by reaction with diazomethane or bis(chloromethyl)mercury
作者:Robert McCrindle、Gilles J. Arsenault、Rajeev Farwaha、Alan J. McAlees、David W. Sneddon
DOI:10.1039/dt9890000761
日期:——
showed at least some tendency to revert to the starting dichloro complexes by loss of the methylene moiety. Products of insertion into a Pd–Br bond are less readily formed than those of the corresponding chloride and the resulting bromomethyl derivatives are less stable than their chloromethyl analogues. Chloromethyl derivatives were also prepared from the dichloride by treatment with bis(chloromethyl)mercury
Anomalous Intramolecular C−H Insertion Reactions of Rhodium Carbenoids: Factors Influencing the Reaction Course and Mechanistic Implications
作者:J. Stephen Clark、Alexander G. Dossetter、Yung-Sing Wong、Robert J. Townsend、William G. Whittingham、C. Adam Russell
DOI:10.1021/jo049900e
日期:2004.5.1
the expected 3(2H)-furanones formed by conventional carbenoidC−Hinsertion. These acetals are the favored C−Hinsertion products in certain circumstances and particularly in cases where carbenoid generation is effected using an electron-deficient rhodium complex. Experiments with simple deuterium labeled substrates reveal that anomalous C−Hinsertion products arise by a mechanism that is distinct from