Cinchona alkaloid squaramide/AgOAc cooperatively catalyzed diastereo- and enantioselective Mannich/cyclization cascade reaction of isocyanoacetates and cyclic trifluoromethyl ketimines.

An efficient diastereo- and enantioselective Mannich-type/cyclization cascade reaction of α-substituted isocyanoacetates and cyclic trifluoromethyl ketimines cooperatively catalyzed by cinchona alkaloid-derived multi-hydrogen-bonding donor squaramide and AgOAc has been investigated, affording the optically active trifluoromethyl-substituted tetrahydroimidazo[1,5-c]quinazoline derivatives in excellent yields (up to 99%) and good to excellent stereoselectivities (up to >15:1 dr, up to 98% ee) under mild conditions.

Cinchona alkaloid squaramide catalyzed enantioselective hydrazination/cyclization cascade reaction of α-isocyanoacetates and azodicarboxylates: synthesis of optically active 1,2,4-triazolines.

An efficient enantioselective hydrazination/cyclization cascade reaction of α-substituted isocyanoacetates to azodicarboxylates catalyzed by Cinchona alkaloid derived squaramide catalysts has been investigated, affording the optically active 1,2,4-triazolines in excellent yields (up to 99%) and good to excellent enantioselectivities (up to 97% ee) under mild conditions.