A green catalytic method for selective synthesis of iodophenols via aerobic oxyiodination under organic solvent-free conditions

Sustainable Aerobic Bromination with Controllable Chemoselectivity

The formation of C-Br(s) is one of the most fundamental reactions in organic synthesis. Oxidative bromination is a "green" way to achieve it. Aerobic bromination has drawn great interest in the past decades, while the poor substrate scope and selectivity, low efficiency, and the use of metal catalyst still confine its application. In this article, we establish a transition-metal-free aerobic bromination promoted by ionic liquid in a catalytic amount with controllable chemoselectivity toward numbers of C-Br(s) formed, and both NaBr/AcOH and HBr(aq) could be used as the bromine source. This methodology shows high efficiency and has a broad substrate scope for various kinds of C-H(s). We also validate this system by the gram-scale (one-pot) synthesis of functional molecules and direct recycle of the catalyst. The possible radical pathway of this catalysis is also presented with evidence.

A Green Alternative for the Direct Aerobic Iodination of Arenes Using Molecular Iodine and a POM@MOF Catalyst

Iodoarenes are important precursors for fine chemicals and pharmaceuticals. The direct iodination of arenes using molecular iodine (I₂) has emerged as an attractive green synthesis method. Most of the direct iodination protocols are still homogeneous systems that require harsh conditions and use or produce toxic products. We report a new heterogeneous catalytic route for the direct aerobic iodination of arenes under mild conditions using a PMoV₂ polyoxometalate (POM) embedded in the metal-organic framework (MOF) MIL-101 (PMoV₂@MIL-101). The catalyst shows full yield for the conversion of mesitylene to 2-iodomesitylene at a rate that is similar to the homogeneous POM system. Moreover, the catalyst is applicable for a wide range of substrates in an oxygen atmosphere without using any co-catalysts or sacrificial agents. To the best of our knowledge, this is the first report on designing a sustainable and green MOF-based heterogeneous catalytic system for the direct iodination reaction using molecular oxygen and iodine.

Synthesis and characterization of a novel ruthenium(ii) trisbipyridine complex magnetic nanocomposite for the selective oxidation of phenols

Anchoring ruthenium(ii) trisbipyridine complex [Ru(Bpy)₃]²⁺ into a magnetic dendritic fibrous silica nanostructure produces an unprecedented strong nanocatalyst, FeNi₃/DFNS/[Ru(Bpy)₃]²⁺.