Etude des effets isotopiques secondaires du deuterium et du carbone 13 associes a unemethylation concurrente de deux铜酸盐, (nC 8 H 17 ) 2 CuLi(PBu 3 ) et (nC 8 H 17 ) 4 CuLi 3 (PBu 3 ), par CH 3 X-CD 3 X et 12,13 CH 3 X (X=I ou OTs)
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.
We report a dual-tasked methylation based on cooperative palladium/norbornene catalysis. Readily available (hetero)aryl halides (39 iodides and 4 bromides) and inexpensive MeOTs or trimethylphosphate are utilized as the substrates and meth-ylating reagent, respectively. Six types of ipso terminations can modularly couple with this ortho C-H methylation to consti-tute a versatile methylation toolbox
Trideuteromethylation of Alkyl and Aryl Bromides by Nickel-Catalyzed Electrochemical Reductive Cross-Electrophile Coupling
作者:Joost Steverlynck、Ruzal Sitdikov、Magnus Rueping、Pavlo Nikolaienko、Ajit Prabhakar Kale
DOI:10.1055/s-0042-1751558
日期:——
A new nickel-catalyzed electrochemical, reductive cross-coupling for the trideuteromethylation of alkyl and arylbromides is reported in which CD3 arenesulfonate derivatives were used as effective and readily available CD3 sources. The CD3-labeled products were obtained with good yields. It was demonstrated that this methodology is scalable and can be efficiently used for various methylations, including