Asymmetric Allylboration of Aldehydes with Pinacol Allylboronates Catalyzed by 1,1′‐Spirobiindane‐7,7′‐diol (SPINOL) Based Phosphoric Acids

Abstract The asymmetric allylboration of aldehydes with pinacolallylboronates catalyzed by 1,1′‐spirobiindane‐7,7′‐diol (SPINOL) based phosphoric acids is described. 6,6′‐Bis(2,4,6‐triisopropylphenyl)SPINOL‐based phosphoric acid was found to be a general, highly enantioselective catalyst for such allylboration reactions and excellent enantioselectivities were obtained for different types of aldehydes including aromatic aldehydes, α,β‐unsaturated aldehydes, propargylic aldehydes, and aliphatic aldehydes.