Complete Stereoretention in the Rhodium-Catalyzed 1,2-Addition of Chiral Secondary and Tertiary Alkyl Potassium Trifluoroborate Salts to Aldehydes
作者:Abel Ros、Varinder K. Aggarwal
DOI:10.1002/anie.200901900
日期:——
Take your new partner by the hand: Chiralsecondary and tertiaryalkyltrifluoroboratesalts undergo rhodium‐catalyzed 1,2‐addition to aldehydes with completestereoretention (handedness) in all cases, enabling the creation of quaternary stereogenic centers with essentially perfect enantioselectivity (see scheme; cod=cycloocta‐1,5‐diene).
Benzylic Boron Reagents Behaving as Allylic Boron Reagents towards Aldehydes: A New Asymmetric Reaction Leading to Homoallylic Alcohols with Concomitant Dearomatisation
作者:Abel Ros、Antonio Bermejo、Varinder K. Aggarwal
DOI:10.1002/chem.201001174
日期:2010.8.23
Retention of stereochemistry: p‐Methoxybenzylic trifluoroborate salts react with aldehydes in the presence of Lewis or Brønsted acids to give homoallylic alcohols with concomitant dearomatisation of the aromatic ring (see scheme). Using enantioenriched benzylic trifluoroborate salts leads to adducts with >98 % retention of the stereochemistry in most cases.