Enriched 13C NMR Monitoring of Methide Reactions

With a 13C label at the methide center, the presence of reactive methide intermediate can be verified and complex reaction products can be inventoried and eventually identified. The only limitations are the synthesis and cost involved in incorporation of the 13C label. As a rule we, only use 13C-labeled dimethylformamide and NaCN as starting materials because of their low cost and availability. Another limitation of enriched 13C-NMR monitoring is dilution of the enriched label to natural abundance levels. Currently, we are developing isotope-editing techniques that utilize unnatural 13C double labels to solve this problem. 

The discoveries made possible by the use of 13C labels are outlined below. A new ene-imine carbon-carbon bond coupling reaction was discovered that afforded 

CHARACTERIZING QUINONE METHIDES BY SPECTRAL GLOBAL FITTING 

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