Synthese und Eigenschaften von 1,2,4,3‐Thiadiazaboretidinen. Kristallstruktur des 2,4‐Di‐<i>tert</i>‐butyl‐3‐phenyl‐1,2,4,3‐thiadiazaboretidins

Synthesis and Properties of 1,2,4,3‐Thiadiazaboretidines. Crystal Structure of 2,4‐Di‐ tert ‐butyl‐3‐phenyl‐1,2,4,3‐thiadiazaboretidine Reaction of sulfur diimides with alkyl(aryl)bis(methylthio)boranes leads to reductive 1,3‐cycloaddition of the NSN sequence with formation of the 1,2,4,3‐thiadiazaboretidines 2a ‐ g . NMR ( 1 H, 11 B, 13 C, 15 N, 29 Si), mass spectra and the results of the X‐ray analysis of 21 are reported and discussed. The 11 B chemical shifts have been calculated for 3‐phenyl‐1,2,4,3‐thiadiazaboretidine and some related model compounds by the IGLO method and correlate acceptably with the experimental values.