Abstract
Fifty-five new five-membered cyclic organophosphorus compounds including oxazaphospholidines, thiazaphospholidines, and Oxathiaphospholanes were synthesized, which have substituents at 4- or /and 5-positions besides at the 2-position. The thiazaphospholidines showed the highest insecticidal activity followed by Oxathiaphospholanes and Oxazaphospholidines. The position preference of substituents in insecticidal activity was most obvious in the Oxazaphospholidines. It was preferable for insecticidal activity to have the substituent near the more basic atom: the 4-position for thiazaphospholidine and oxazaphospholidine, the 5-position for oxathiaphospholane, with the exception of 4- or 5-phenyl oxazaphospholidine.
