Modular Assembly of Pyrrolo[3,4-]isoquinolines through Rh-Catalyzed Cascade C-H Activation/Annulation of -Methyl Aryloximes with Maleimides.

An efficient and practical strategy for the construction of pyrrolo[3,4-]isoquinolines via Rh(III)-catalyzed cascade C-H activation and subsequential annulation process from easily available -methyl aryloximes and maleimides has been disclosed. This facile protocol does not require any inert atmosphere protection with good efficiency in a low loading of catalyst and exhibits good functional group tolerance and broad substrate scope. Notably, the as-prepared products show potential photophysical properties.

A rhodium-catalyzed cascade C-H activation/annulation strategy for the expeditious assembly of pyrrolidinedione-fused 1,2-benzothiazines.

A cascade annulation strategy triggered by rhodium(III)-catalyzed C-H activation has been reported for the expeditious assembly of pyrrolidinedione-fused 1,2-benzothiazines from free NH-sulfoximines with maleimides under mild conditions. Without the need for inert atmosphere protection, a broad range of sulfoximines with maleimides were well tolerated, producing diverse fused-thiazine derivatives in moderate to good yields. Additionally, the late-stage transformation of the target product demonstrated the potential synthetic value of this protocol.

Synthesis of arene-functionalized fused heterocyclic scaffolds a regioselective cascade 1,4-conjugate addition/5- annulation strategy.

Facile access to furan fused heterocyclic scaffolds through a regioselective cascade reaction of propargylamines with 4-hydroxy-2-pyran-2-ones and 4-hydroxy-6-methylpyridin-2(1)-one has been achieved. This cascade reaction presumably involves the formation of -alkynyl quinone methide (-AQM), 1,4-conjugate addition, followed by regioselective 5- annulation, and a 1,3-H shift process. Moreover, the reaction provides a new and efficient method for the synthesis of highly sterically congested 3-phenolic furo[3,2-]pyran-4-ones and furo[3,2-]pyridin-4(5)-ones by the formation of a furan ring from readily available starting materials in good to high yields (50-82%) with broad functional group compatibility in a single step.