Highly Enantioselective and Efficient Synthesis of Flavanones Including Pinostrobin through the Rhodium-Catalyzed Asymmetric 1,4-Addition
作者:Toshinobu Korenaga、Keigo Hayashi、Yusuke Akaki、Ryota Maenishi、Takashi Sakai
DOI:10.1021/ol2004148
日期:2011.4.15
An efficient synthesis of bioactive chiral flavanones (1) was achieved through the Rh-catalyzed asymmetric 1,4-addition of arylboronic acid 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
有效的合成生物活性手性黄烷酮(1)是通过Rh催化的芳基硼酸到色酮的不对称1,4-加成反应而实现的。在室温下,在0.5%Rh催化剂和贫电子手性二膦MeO-F 12 -BIPHEP的存在下,甲苯中的反应平稳进行。在该反应中,经常发生向(S)-1的1,2-加成反应生成副产物(2 S,4 R)-2,4-二芳基-4-苯并二氢呋喃,可通过改变反应溶剂来减少CH 2 Cl 2使Rh催化剂失活(需要3%)。