One-pot synthesis and theoretical calculation for trifluoromethylated pyrrolizidines by 1,3-dipolar cycloaddition with azomethine ylides and β-trifluoromethyl acrylamides.

The reaction with β-trifluoromethyl acrylamide 3e and azomethine ylides generated from l -proline and several aldehydes provided the corresponding trifluoromethylated pyrrolizidines with excellent diastereoselectivity (>20/1) in all cases and moderate regioselectivity (up to 1/5.9). A DFT calculation was also examined to reveal the origin of these stereoselectivities. [ABSTRACT FROM AUTHOR]