A chiral N-sulfonylphosphoramide: Synthesis and X-ray crystal structure of a 1,3,2-oxazaphospholidin-5-one, a trivalent electron-withdrawing amino acid-derived phosphorus compound, and synthesis of its W(CO)(5) adduct

摘要

Reaction of the amino acid derivative (S)-N-tolylsulfonylvaline with PhPCl2 and NEt3 gives in >90% yield a novel chiral phosphorus heterocycle as a greater than 7:1 mixture of diastereomers. The X-ray crystal structure of the major isomer 7a shows that the isopropyl and phenyl groups are mutually cia. The IR spectrum of the W(CO)(5) adduct of 7a shows that the N-sulfonyl and carboxylate moieties make it a strongly electron-withdrawing ligand. [References: 28]