Abstract: Cobalt(II) complexes of the D2-symmetric chiral porphyrins are effective catalysts for asymmetric cyclopropanation reactions with succinimidyl diazoacetate. The Co-catalyzed reaction is suitable for various olefins, providing the corresponding cyclopropane succinimidyl esters in high yields and excellent diastereo- and enantio-selectivity.

Abstract: Cobalt (II) complexes of porphyrins are effective catalysts for intramolecular nitrene insertion of C—H bonds with arylsulfonyl azides. The cobalt-catalyzed process can proceed efficiently under mild and neutral conditions in low catalyst loading without the need of other reagents or additives, generating nitrogen gas as the only byproduct.

Abstract: Cobalt(II) complex of P1 [Co(P1)], a new porphyrin that was designed on the basis of potential hydrogen bonding interactions in the metal-nitrene intermediate, is a highly active catalyst for olefin aziridination with azides. The [Co(P1)]-based system can be effectively employed for different combinations of aromatic olefins and arysulfonyl azides, synthesizing various sulfonylated aziridines in excellent yields. Besides its mild catalytic conditions, the Co-catalyzed aziridination process enjoys several attributes associated with the relatively low cost of cobalt and widely accessible arylsulfonyl azides. Furthermore, it generates stable dinitrogen as the only by-product.

Abstract: Cobalt (II) complexes of porphyrins are effective catalysts for intramolecular nitrene insertion of C—H bonds with arylsulfonyl azides. The cobalt-catalyzed process can proceed efficiently under mild and neutral conditions in low catalyst loading without the need of other reagents or additives, generating nitrogen gas as the only byproduct.