3,5,7-trimethyl-1-azatricyclo[3.3.1.1(3,7)]decan-2-ylidene, an aminocarbene without pi conjugation

3,5,7-trimethyl-1 -azatricyclo[3.3.1.1(3,7)]decan-2-ylidene, an aminocarbene without pi conjugation, has been generated from the corresponding tosylhydrazone salt. Addition of the carbene to alkenes is stereospecifically cis, thus showing that the reacting state is singlet. Competition studies reveal that the carbene is somewhat nucleophilic, implying a measure of overlap between the lone pair on nitrogen and the empty orbital on carbon. In turn, such overlap implies a pyramidal structure for the divalent carbon.