Enzyme- and ruthenium-catalyzed dynamic kinetic resolution of functionalized cyclic allylic alcohols.

Enantioselective synthesis of functionalized cyclic allylic alcohols via dynamic kinetic resolution has been developed. Cyclopentadienylruthenium catalysts were used for the racemization, and lipase PS-IM or CALB was employed for the resolution. By optimization of the reaction conditions the formation of the enone byproduct was minimized, making it possible to prepare a range of optically active functionalized allylic alcohols in good yields and high ee's.

Palladium(II)-catalyzed oxidative cyclization of allylic tosylcarbamates: scope, derivatization, and mechanistic aspects.

A highly selective oxidative palladium(II)-catalyzed (Wacker-type) cyclization of readily available allylic tosylcarbamates is reported. This operationally simple catalytic reaction furnishes tosyl-protected vinyl-oxazolidinones, common precursors to syn-1,2-amino alcohols, in high yield and excellent diasteroselectivity (>20:1). It is demonstrated that both stoichiometric amounts of benzoquinone (BQ) as well as aerobic reoxidation (molecular oxygen) is suitable for this transformation. The title reaction is shown to proceed through overall trans-amidopalladation of the olefin followed by ß-hydride elimination. This process is scalable and the products are suitable for a range of subsequent transformations such as: kinetic resolution (KR) and oxidative Heck-, Wacker-, and metathesis reactions.

Enantioselective synthesis of syn- and anti-1,3-aminoalcohols via ß-aminoketones and subsequent reduction/dynamic kinetic asymmetric transformation.

ß-Aminoketones obtained from imines in an organocatalytic Mannich reaction were transformed to enantio- and diastereomerically pure 1,3-aminoalcohols with two stereogenic centers via a combined reduction/dynamic kinetic asymmetric transformation. Both syn and anti diastereomers were obtained in high yield, dr, and ee.