Temperature‐Dependent Cinchona Alkaloid Squaramide‐Catalyzed Asymmetric Formal [3+2] Cycloaddition of Isocyanoacetates with β‐Trifluoromethylated Enones

An efficient temperature‐dependent organocatalyzed asymmetric formal [3+2] cycloaddition reaction of α‐substituted isocyanoacetates to β‐trifluoromethylated enones by cinchona alkaloid‐derived squaramide has been investigated, affording the optically active trifluoromethylated 2‐pyrrolines in excellent yields (up to 98 %) and high stereoselectivities (>20:1 dr , up to >99 % ee ) under mild conditions.