1,3-ditert-butyl-2,2-dichloro-1,3,2-diazagermolidine

2-tert-butyl-1,2,5-thiadiazolidine 1,1-dioxide

2-tert-butyl-5-ethyl-1,2,5-thiadiazolidine 1,1-dioxide

1,3-ditert-butyl-2-chloro-1,3,2-diazaphospholidine

1,3-ditert-butyl-1,3,2-diazaphospholidine