Chiral o-methoxyaryldiazaphosphonamides - A new class of efficient Lewis bases in the catalytic asymmetric ring opening of cyclooctene oxide with silicon tetrachloride

The synthesis of a new class of chiral o-methoxydiazaphosphonamides (as Lew is bases) has been investigated, together with their use as catalysts in th e asymmetric ring opening (ARO) of cyclooctene oxide with silicon tetrachlo ride. Enantiomeric excesses varying from 6 to 99% ee were observed, dependi ng on the nature of the catalyst examined. On the basis of experimental con siderations, a mechanistic rationale involving hexacoordinate silicon speci es has been proposed.