Stereocontrolled Pericyclic and Radical Cycloaddition Reactions of Readily Accessible Chiral Alkenyl Diazaborolidines.

In this paper is described an easily synthesized chiral diazaborolidine that is inexpensive, stable, and provides excellent stereoselection across a number of reaction classes. These versatile compounds possess utility in four different classes of cycloaddition reactions, offering good yield and stereoselectivity. X-ray structure analysis provides insight about the origin of stereocontrol.

Diastereoselective Diboration of Cyclic Alkenes: Application to the Synthesis of Aristeromycin.

The Pt-catalyzed diboration of cyclic alkenes is extended to unsaturated heterocycles and bicyclic compounds and can be accomplished in a diastereoselective fashion. The optimal procedures, substrate scope, and diastereoselectivity were investigated, and examples employing both homogeneous and heterogeneous catalysis were examined. Lastly, application to the construction of the nucleoside analog (±)-aristeromycin was conducted.

Alkyl Group Migration in Ni-Catalyzed Conjunctive Coupling with C(sp3) Electrophiles: Reaction Development and Application to Targets of Interest.

A catalytic conjunctive cross-coupling reaction is developed that allows the construction of chiral organoboronic esters from alkylboron ate complexes and alkyl iodide electrophiles. The process occurs most efficiently with a Ni/Pybox-comprised catalyst and with an acenapthoquinone-derived boron ligand. Because of the broad functional group tolerance of this reaction, it can be a versatile tool for organic synthesis. Applications to the construction of (R)-coniine and (-)-indolizidine 209D are described.