The enantioselective aza-Friedel–Crafts reaction is one of the most straightforward and efficient strategies for constructing a new carbon-carbon bond bearing quaternary stereocenter in organic synthesis, but the catalytic asymmetric aza-...

A chiral phosphoric acid‐catalyzed enantioselective aza‐Friedel–Crafts reaction of 5‐aminopyrazole derivatives with cyclic ketimines attached to a neutral functional group is reported. This protocol allows the formation of pyrazole‐based C2‐quaternary indolin‐3‐ones with high enantioselectivities and regioselectivities. Moreover, gram‐scale synthesis of the 5‐aminopyrazole‐based C2‐quaternary indolin‐3‐ones was performed, with no decrease in the yield and enantioselectivity.

A Friedel–Crafts reaction of indolizines with 2‐aryl‐3H‐indol‐3‐ones catalyzed by B(C6F5)3 is described. This protocol gives access to indolizine derivatives that are valuable building blocks in synthetic and pharmaceutical chemistry. The reaction proceeds under mild conditions, affording various C2‐quaternary indolin‐3‐ones based on indolizine with high yields and regioselectivities. Moreover, the synthetic transformations of the target products were realized by N‐methylation and trifluoromethane sulfonation.