以手性配体(6a,6b,7a,7b,8)的MgI2·I络合物作为手性路易斯酸催化剂,探讨了2-亚甲基-1-苯基-1,3-丁二酮与1,3-环戊二烯的Diels-Alder反应.在-90℃和-50℃时,得到高的非对映异构选择性(exo∶endo≥94∶6).
The synthesis of 2-methylene-1-phenyl-
A pneumatic launcher is theoretically investigated to study its natural transverse vibration in water. Considering the mass effect of the sealing cover, the lau