After some preliminary screening studies, our initial reaction conditions for the cyclization of (E)-2'-triflylchalcone 1a (X = OTf) employed a catalyst system comprised of 5 mol % of Pd(OAc) 2 , 10 mol % of (R)-BINAP, and 2 equiv of Hünig's base in DMF at 100 °C (Table 1, entry 1). We observed that the cyclization provided the desired product 2a in 32% yield with an enantiomeric excess of 54%. 9 Variation of the amine base revealed that proton sponge gave the ...
