Stereochemistry in the hydroboration of allylsilanes

Enantiomerically enriched tris(boronates): readily accessible conjunctive reagents for asymmetric synthesis

The catalytic enantioselective diboration of vinyl boronate esters furnishes chiral tris(boronates) in a selective fashion. Subsequent deborylative alkylation occurs in a diastereoselective fashion, both for intermolecular and intramolecular processes.

Allylation of nitrosobenzene with pinacol allylboronates. A regioselective complement to peroxide oxidation

Addition of nitrosobenzene to pinacol allylboronates leads to oxidation of the organoboron with concomitant rearrangement of the substrate alkene. This reaction appears to proceed by allylboration of the nitroso group in analogy to carbonyl and imine allylation reactions. Remarkably, the N-O bond is cleaved during the reaction such that simple alcohols are the final reaction product.

Modular Asymmetric Synthesis of 1,2-Diols by Single-Pot Allene Diboration/Hydroboration/Cross-Coupling

Chiral allyl vinyl boronates are generated by catalytic enantioselective diboration of prochiral allenes. They may then be reacted, in situ, with a hydroborating reagent to form a novel triboron intermediate. The least hindered and most reactive C-B bond then participates in cross-coupling wherein the coupling is brought about by the same catalyst as that which catalyzed the diboration reaction. The remaining C-B bonds are then oxidized in the reaction workup, thereby allowing for the modular synthesis of chiral diols in a concise single-pot fashion.