Conjugated Microporous Polymer as Heterogeneous Ligand for Highly Selective Oxidative Heck Reaction.

A series of pyridine-type ligands containing C≡C bonds were designed and synthesized for selective oxidative Heck reaction. These ligands were utilized as functional units and integrated into the skeleton of conjugated microporous polymers. 6,6'-diiodo-2,2'-bipyridine and 1,3,5-triethynylbenzene were polycondensed via Sonogashira cross-coupling strategy to afford CMP-1 material. The resultant CMP-1 was used as a heterogeneous catalytic ligand for the PdII-catalyzed oxidative Heck reaction with high linear selectivity. The linear selectivity of CMP-1 is about 30 times higher than that of bipyridine-based monomer ligand. This work opens a new front of using CMP as an intriguing platform for developing highly efficient catalysts in controlling the regioselectivity in organic reactions.

Silver(I)-Catalyzed Tandem Sigamatropic Rearrangement/1,3-H Shift/6π Aza-electrocyclization of N-Propargylic Hydrazones: A Mild Synthetic Route to 1,6-Dihydropyridazines.

A highly efficient AgOTf catalyzed [3,3] sigmatropic rearrangement/1,3-H shift/6π aza-electrocyclization cascade reaction of N-propargylic hydrazones has been developed. This method provides a new mild synthetic route to various polysubstituted 1,6-dihydropyridazines including the 3-CF3-substituted ones with high selectivity.

Synthesis of 5,6-Dihydropyrazolo[5,1-a]isoquinolines through Indium(III)-Promoted Halocyclizations of N-Propargylic Sulfonylhydrazones.

A novel method for the preparation of 5,6-dihydropyrazolo[5,1-a]isoquinoline via indium(III)-promoted halocyclizations of N-propargylic sulfonylhydrazones has been developed. The pyrazole and 3,4-dihydroisoquinoline moieties were synchronously formed via a cascade cyclization reaction using easily assembled open-chain compounds. The pyrazole and 3,4-dihydroisoquinoline moieties were formed via a cascade cyclization reaction using easily assembled open-chain compounds.