Recent advances in synthetic transformations mediated by cerium(IV) ammonium nitrate.

Cerium(IV) ammonium nitrate (CAN) has recently emerged as a versatile reagent for oxidative electron transfer; the overwhelming number of reports serve as a testimony to the unparalleled utility of CAN in a variety of transformations of synthetic importance. Our recent work has uncovered novel carbon-carbon bond-forming reactions leading to the one-pot synthesis of dihydrofurans, tetrahydrofurans, and aminotetralins. In addition, we have developed a number of facile carbon-heteroatom bond-forming reactions by the CAN-mediated oxidative addition of soft anions to alkenes. A mechanistic rationale has been provided for the reactions explored. As might be expected of very powerful one-electron oxidants, the chemistry of cerium(IV) oxidation of organic molecules is dominated by radical and radical cation chemistry.

Strategies for heterocyclic construction via novel multicomponent reactions based on isocyanides and nucleophilic carbenes.

This Account focuses mainly on our recent endeavors in the area of multicomponent reactions (MCRs) involving zwitterionic species generated by the addition of isocyanides and nucleophilic carbenes such as dimethoxycarbene and N-heterocyclic carbenes to activated alkynes. The strategy employed encompasses the interception of 1:1 zwitterionic species, generated in situ with a wide range of electrophiles. The new MCRs developed offer an efficient and convenient entry into several heterocycles of biological and synthetic importance.