Kim Hanbyul, Choi Su Yeon, Shin Seunghoon
Department of Chemistry, Research Institute for Natural Sciences and Center for New Directions in Organic Synthesis (CNOS), Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Korea.
Angew Chem Int Ed Engl. 2018 Oct 1;57(40):13130-13134. doi: 10.1002/anie.201807514. Epub 2018 Sep 4.
Intermolecular asymmetric gold catalysis involving alkyne activation presents a significant challenge due to its distinct mechanistic mode from other metals. Herein, we report a highly enantioselective synthesis of α,β-unsaturated δ-lactones from [4+2] annulation of propiolates and alkenes in upto 95 % ee. Notably, for the desired chiral recognition, the choice of 1,1,2,2-tetrachloroethane as solvent was found to be crucial. Furthermore, an anionic surfactant (sodium dodecyl sulfate) improved the product selectivity in the divergence of the cyclopropyl gold carbene intermediate.
由于分子间不对称金催化炔烃活化的机理模式与其他金属不同，因此面临重大挑战。在此，我们报道了通过丙炔酸酯与烯烃的[4+2]环化反应，以高达95%的对映体过量（ee）值实现α,β-不饱和δ-内酯的高度对映选择性合成。值得注意的是，对于所需的手性识别，发现选择1,1,2,2-四氯乙烷作为溶剂至关重要。此外，一种阴离子表面活性剂（十二烷基硫酸钠）在环丙基金卡宾中间体的分歧过程中提高了产物选择性。
