Rh(I)-Catalyzed Isomerization ofN-Allylaziridines to Z-Enamines

Significance

Using RhH(CO)(PPh₃)₃ as catalyst, a variety of N-allylaziridines can be selectively converted into Z-aziridinylenamines in good to quantitative yields, and with impressive Z/E selectivity. Only unsubstituted allyl groups worked well, as N-prenylaziridine only afforded traces of product. The aziridine moiety proved to be important, as N-allylmorpholine afforded solely the E-enamine under the reaction conditions. In addition, a Z-enamine product was converted into an aziridinylcyclobutene via cycloaddition with an activated alkyne. The product retains the cis stereochemistry found in the enamine.