First synthesis of P-chirogenic prophosphatranes

Syntheses are reported for the novel P-chirogenic bicyclic prophosphatranes P(RNCH2CH2)2N(OCH2CH2)-(8) in which the two R groups [i.e., 1-methylenenaphthyl and 1,2-methoxybenzyl (8)] and in its corresponding phosphine oxide (9) are different. Also synthesized was the transannulated protonated phosphatrane cation in the salt [HP(RNCH2CH2)3N]Cl in which the three R groups [i.e., 1-methylenenaphthyl, 1,2-methoxybenzyl, and (S)-1-phenethyl (14)] are different, and also in its corresponding deprotonated prophosphatrane form P(RNCH2CH2)3N (15). Good analytical resolution of racemic 9 is reported, whereas only partial resolution was achieved for diastereomeric 14.