New and efficient syntheses of symmetrical phosphorus-containing cryptands
Abstract
Phosphorus cryptands 3–5 are obtained via[2 + 3] cyclocondensations between phosphodiydrazides 1a, b and phosphorus-p,p-dialdehydes 2a, b while another phosphorus cryptand 10 is prepared by treatment of the sodium salt of a phosphodihydrazone 8 with a dihalogenated phosphorus-containing macrocycle 9.