Conversion of Propargylic Amines with CO 2 Catalyzed by a Highly Stable Copper(I) Iodide Thorium-Based Heterometal-Organic Framework.

The conversion of CO 2 to generate high-value-added chemicals has become one of the hot research topics in green synthesis. Thereinto, the cyclization reaction of propargylic amines with CO 2 is highly attractive because the resultant oxazolidinones are widely found in pharmaceutical chemistry. Cu(I)-based metal-organic frameworks (MOFs) as catalysts exhibit promising application prospects for CO 2 conversion. However, their practical application was greatly limited due to Cu(I) being liable to disproportionation or oxidization. Herein, the solid copper(I) iodide thorium-based porous framework {[Cu 5 I 6 Th 6 (μ 3 -O) 4 (μ 3 -OH) 4 (H 2 O) 10 (L) 10 ]·OH·4DMF·H 2 O} n ( 1 ) (HL = 2-methylpyridine-4-carboxylic acid) constructed by [Th 6 ] clusters and [Cu x I y ] subunits was successfully prepared and structurally characterized. To our knowledge, this is the first copper(I) iodide-based actinide organic framework. Catalytic investigations indicate that 1 can effectively catalyze the cyclization of propargylic amines with CO 2 under ambient conditions, which can be reused at least five times without a remarkable decline of catalytic activity. Importantly, 1 exhibits excellent chemical stability and the oxidation state of Cu(I) in it can remain stable under various conditions. This work can provide a valuable strategy for the synthesis of stable Cu(I)-MOF materials.