In situ preparation of rhodium/N-heterocyclic carbene complexes and use for addition of arylboronic acids to aldehydes

Abstract

(Chemical Equation Presented) The in situ prepared three component system [RhCl(COD)]2/imidazolidinium salts (2, 4) and KOBut catalyses the addition of phenylboronic acid to sterically hindered aldehydes affording the corresponding arylated secondary alcohols in good yields. Four novel 1,3-dialkylimidazolidinium (2-4) salts as NHC precursors were synthesized from N,N′-dialkylethylenediamine.