N-heteroarylphosphonates, Part II. Synthesis and reactions of 2-and 4-phosphonatoquinolines and related compounds

We extend our synthetic method for the efficient preparation of dialkoxypho sphoryl- and phosphonio-disubstituted pyridines to include the preparation of other phosphonato substituted N-heterocycles. The key to the success of this method lies in the employment of cationic N-(trifluoromethylsulfonyl)h eteroarylium triflates that are activated towards nucleophilic attack. The P(O)(OR)(2) group can be transformed into the P(S)(OR)(2) functionality. We report first attempts to substitute the P(O)(OR)(2) moiety with C-nucleoph iles. In addition to our synthetic results, the X-ray structures of two (di methoxyphosphoryl)trifluoromethanesulfonyldihydro-N-heteroarenes are discus sed. We also give complete carbon (C-13) and phosphorus (P-31)-NMR spectra of a series of 2- and 4-phosphonic ester substituted heteroaryl compounds a nd their dihydro analogs.