A highlyenantioselective addition of alcohols to cyclic trifluoromethyl ketimines is developed catalyzed by quinine-thiourea, giving biologically interesting N,O-ketals in up to 99% yield and 96% ee.
N-Heterocyclic carbene-catalyzed [4+2] annulation of β-methyl enals and cyclic trifluoromethyl ketimines for the asymmetric synthesis of dihydroquinazolinone derivatives
The enantioselective oxidative N-heterocyclic carbene-catalyzed [4+2] annulation reaction of β-methyl enals and cyclic trifluoromethyl ketimines has been developed. A series of biologically interesting dihydroquinazolinone derivatives bearing a trifluoromethyl group and a tetrasubstituted stereocenter are efficiently prepared with very good yields and excellent stereoselectivities.
Quinine-thiourea catalyzed enantioselective hydrophosphonylation of trifluoromethyl 2(1H)-quinazolinones
作者:Hexin Xie、Aiguo Song、Xinshuai Zhang、Xiaobei Chen、Hao Li、Chunquan Sheng、Wei Wang
DOI:10.1039/c2cc38097h
日期:——
An organocatalytic enantioselective addition reaction of cyclic ketoimines with phosphites has been developed for the first time. The process, catalyzed by Soós' quinine thiourea, affords synthetically and medicinally interesting enantioenriched trifluoromethyl dihydroquinazolinones in high yields and with high enantioselectivities.
Hydrogen-Bond-Directed Enantioselective Decarboxylative Mannich Reaction of β-Ketoacids with Ketimines: Application to the Synthesis of Anti-HIV Drug DPC 083
作者:Hai-Na Yuan、Shuai Wang、Jing Nie、Wei Meng、Qingwei Yao、Jun-An Ma
DOI:10.1002/anie.201210361
日期:2013.4.2
Key to success: The title reaction provides facile access to enantioenriched 3,4‐dihydroquinazolin‐2(1H)‐ones containing a quaternary stereogenic center in high yields with excellent enantioselectivities. Subsequent transformations lead to the convenient preparation of the anti‐HIV drug DPC 083 and N‐fused polycyclic compounds without loss of enantiomeric excess.
Asymmetricarylation of 4‐fluoroalkyl‐2‐quinazolinone derivatives with arylboronic acids proceeded smoothly in the presence of a cationic palladiumcatalyst (1 mol %) coordinated with a chiral phosphinooxazoline (phox) ligand to create the corresponding fluorine‐containing arylated dihydroquinazolinones in high yields and with greater than 99 % ee.