An efficient synthesis of bioactive chiralflavanones (1) was achieved through the Rh-catalyzed asymmetric1,4-addition of arylboronicacid to chromone. The reaction in toluene proceeded smoothly at room temperature in the presence of 0.5% Rh catalyst with electron-poor chiral diphosphine MeO-F12-BIPHEP. In this reaction, the 1,2-addition to (S)-1 frequently occurred to yield (2S,4R)-2,4-diaryl-4-chromanol