Yao Weijun, Yu Zhaoyuan, Wen Shan, Ni Huanzhen, Ullah Nisar, Lan Yu, Lu Yixin
Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543 . Email:
School of Chemistry and Chemical Engineering , Chongqing University , Chongqing 400030 , P. R. China . Email:
Chem Sci. 2017 Jul 1;8(7):5196-5200. doi: 10.1039/c7sc00952f. Epub 2017 May 17.
Enantioselective intramolecular [3 + 2] annulation of chalcones bearing an allene moiety has been successfully developed. The reaction was effectively promoted by amino acid-derived phosphines, in combination with achiral Brønsted acids. Dihydrocoumarin architectures were constructed in high yields and with excellent enantiomeric excesses. Theoretical studies DFT calculations revealed that the hydrogen bonding network induced by achiral Brønsted acids/chiral phosphines could more efficiently distinguish between two enantioselective pathways, thus leading to enhanced enantioselectivity.
含丙二烯部分的查尔酮的对映选择性分子内[3+2]环化反应已成功开发。该反应通过氨基酸衍生的膦与非手性布朗斯特酸联合有效地促进。二氢香豆素结构以高产率和优异的对映体过量值构建。理论研究（DFT计算）表明，非手性布朗斯特酸/手性膦诱导的氢键网络能够更有效地区分两条对映选择性途径，从而导致对映选择性增强。
