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A combined Lewis acid system comprising of two or more Lewis acids occasionally exhibits augmented catalytic activity in organic transformations which are otherwise unrealizable by either of the components exclusively. On the other hand, the efficient construction of multiple new C-C bonds and polycyclic structures in minimal steps remains a subject of great interest in both academia and industry. Herein we report an efficient method to assemble aryldihydronaphthalene derivatives via a cascade reaction of diarylalkynes with acrylates under the catalysis of a combined Lewis acid derived from In(III) salt and TMSBr. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) Published version

An efficient iron(II)-catalyzed alkoxycarbonylation reaction between N-vinylacetamides and carbazates is reported. The corresponding useful highly substituted (β-acylamino)acrylates could be obtained in reasonable to good yields and stereoselectivity under mild reaction conditions.

An efficient iron(II)-catalyzed alkoxycarbonylation reaction between N-vinylacetamides and carbazates is reported. The corresponding useful highly substituted (β-acylamino)acrylates could be obtained in reasonable to good yields and stereoselectivity under mild reaction conditions.

Various N-vinylacetamides undergo Pd-catalyzed coupling with bromoalkyne (II) to afford the corresponding alkynylated products in good yields.

A cyclization reaction between enamides and alkynes catalyzed by palladium(II) acetate is described. In this method, the molecular oxygen serves as an efficient oxidant for the Pd(II)/Pd(0) catalytic cycle. The simple reaction conditions permit this methodology to be used as a general tool for the preparation of multi-substituted pyrroles.

A direct ethynylation reaction between N-vinylacetamides and (bromoethynyl)triisopropylsilane catalyzed by palladium is reported. A broad scope of cyclic N-vinylacetamide derivatives was tolerated and the corresponding products could be obtained in acceptable yields. This work provides a general tool for the synthesis of conjugated enyne products using palladium(II) acetate as catalyst. The mild reaction conditions and reasonable results should make this method a useful synthetic protocol. Unfortunately, other bromo-substituted alkynes are found to be unreactive and could not afford the desired products under the current reaction conditions.