Optically active 1,1′-Spirobiindane-7,7′-diol (SPINOL)-based phosphoric acids as highly enantioselective catalysts for asymmetric organocatalysis
The synthesis and application of a series of optically active 1,1′-spirobiindane-7,7′-diol (SPINOL)-based phosphoric acids are described. These SPINOL-based phosphoric acids were prepared from (R)-SPINOL in three steps and exhibited excellent enantioselec
SPINOL-derived phosphoric acids: Synthesis and application in enantioselective Friedel-Crafts reaction of indoles with imines
A new class of chiral phosphoric acids with spirobiindane as scaffold were conveniently synthesized from (S)-1,1′-spirobiindane-7,7′-diol ((S)-SPINOL) and employed to catalyze the asymmetric Friedel-Crafts reaction of indoles with imines to afford 3-indol