Synthesis of Highly Substituted Imidazolidine-2,4-dione (Hydantoin) through Tf<sub>2</sub>O-Mediated Dual Activation of Boc-Protected Dipeptidyl Compounds
作者:Hui Liu、Zhimin Yang、Zhengying Pan
DOI:10.1021/ol502900j
日期:2014.11.21
Highly substituted chiral hydantoins were readily synthesized from simple dipeptides in a single step under mild conditions. This reaction proceeded through the dual activation of an amide and a tert-butyloxycarbonyl (Boc) protecting group by Tf2O-pyridine. This method was successfully applied in the preparation of a variety of biologically active compounds, including drug analogs and natural products
A photochemical deracemization of 5-substituted 3-phenylimidazolidine-2,4-diones (hydantoins) is reported (27 examples, 69%-quant., 80–99% ee). The reaction is catalyzed by a chiral diarylketone which displays a two-point hydrogen bonding site. Mechanistic evidence (DFT calculations, radical clock experiments, H/D labeling) suggests the reaction to occur by selective hydrogenatom transfer (HAT). Upon