RESUMEN
Olefins play an essential role in synthetic chemistry, serving not only as important synthons but also as key functional groups in numerous bio-active molecules. Consequently, there has been considerable interest in the development of more powerful methods for olefins. While the Wittig reaction stands as a prominent choice for olefin synthesis due to its simplicity and the ready availability of raw materials, its limitation lies in the challenge of controlling cis-trans selectivity, hampering its broader application. In this study, a novel Boron-Wittig reaction has been developed utilizing gem-bis(boryl)alkanes and aldehydes as starting materials. This method enables creating favourable intermediates, which possess less steric hindrance, and leading to trans-olefins via intramolecular O-B bonds elimination. Notably, synthesis studies have validated its good efficacy in modifying bioactive molecules and synthesizing drug molecules with great trans-selectivity. Furthermore, the reaction mechanism was elucidated based on intermediate trapping experiments, isotope labelling studies, and kinetic analyses.
RESUMEN
The palladium-catalyzed highly regio- and diastereoselective arylboration of alkenylarenes has been developed. This chemistry afforded the benzylic boronic esters with a broad substrate scope, which are valuable synthetic intermediates for organic synthesis. The chiral anion phase-transfer strategy was designed for this transformation to realize the regio-, diastereo-, and enantioselective control of this reaction simultaneously.