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A facile in situ formed primary amine-imine organocatalyst was developed in the asymmetric Michael addition of substituted 4-hydroxycoumarins to cyclic enones. A series of optically active polycyclic coumarin derivatives were obtained in high yields with excellent enantioselectivities up to 97% ee.Coumarin derivatives are distributed in a large number of natural products and are commonly used as versatile intermediates in natural product synthesis. 1 Modification of this class of compound has been of great interest to chemists due to their various biological activities to antimalarial, anticoagulant, and anti-HIV activities, etc. 2 Although most of coumarin derivatives are currently prescribed as the racemate, activity and metabolism are markedly dissimilar for the two enantiomers. 3 Therefore, efficient asymmetric syntheses of coumarins are of longstanding interest. 4 Organocatalysis has proven itself a valuable strategy in the preparation of the synthesis of optically active coumarins 5 since Jørgensen reported a onestep synthesis of enantiomerically pure warfarin in 2003. 6 They presented the first example of an imidazolidine organocatalyst promoted asymmetric Michael reaction of coumarin and R,β-unsaturated ketones. 7 Chin and Chen

An unprecedented application of trifluoromethanesulfonyl hydrazides as trifluoromethylating agents has been demonstrated in two vicinal difunctionalization reactions of terminal alkenes: the copper-catalyzed three-component vicinal chlorotrifluoromethylation of arylakenes with TfNHNHBoc and NaCl and the tandem trifluoromethylation/cyclization of N-arylacrylamides with TfNHNHBoc. The reactions proceeded in the presence of inexpensive oxidants under mild conditions and provided a range of structurally diverse trifluoromethyl-containing compounds with high regioselectivity.

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