铜基金属有机大环催化叠氮-炔烃环加成反应

Cu-based metal-organic macrocycle catalyst for azide-alkyne cycloaddition

摘要:

以咔唑为原料，经过维尔斯迈尔－哈克反应以及席夫碱缩合反应得到含有硫脲基团的咔唑基配体〔2,2'-（（9-丁基-9H-咔唑-3,6-二基）双（亚甲基亚烷基））双（肼-1-碳硫酰胺）〕(DCT)，与金属铜离子构筑了一例[2+2]型金属有机大环〔[Cu2(DCT)2Br2]·1.6(C3H7NO)·1.6(CH3OH)〕(CuBr-DCT)，并通过单晶X射线衍射和固体紫外可见吸收光谱对产物进行表征。结果表明，CuBr-DCT具有良好的光化学物理性能，可作为铜催化的叠氮化物-炔烃环加成反应(CuAAC)的非均相催化剂。反应体系包括叠氮化合物、炔烃、三乙胺（电子牺牲剂）及催化剂四部分。在体系中，金属有机大环(CuBr-DCT)充当非均相催化剂的角色，在反应结束后容易分离回收，且能够避免一价铜盐催化该反应时容易发生的歧化或氧化反应。结果证实，室温下利用家用节能灯进行照射时，CuBr-DCT为催化剂，该反应转化率可达100%，且产物具有单一性。

Abstract:

A case of Cu-based metal-organic macrocycle, 〔[Cu2(DCT)2Br2]·1.6(C3H7NO)·1.6(CH3OH) 〕(CuBr-DCT), is constructed from thiourea–groups-containing carbazole-based ligands DCT 〔2,2'-((9-butyl-9H-carbazole-3,6-diyl)bis(methanylylidene))bis(hydrazine-1-carbothioamide)〕and characterized by single-crystal X-ray diffraction and Solid-state UV-Vis absorption spectra. CuBr-DCT shows good photochemical physical properties and can be used as a heterogeneous catalyst with excellent performance for copper-catalyzed azide-alkyne cycloaddition (CuAAC). The reaction system is composed of azide, alkyne, triethylamine (electron donor) and catalyst. As a heterogeneous catalyst, metal-organic macrocycle (CuBr-DCT) is easy to separate and recycle after the reaction, and can avoid the disproportionation or oxidation reaction of Cu(I) salt in the reaction process. CuBr-DCT exhibits excellent catalytic effect on CuAAC. Under room temperature and the irradiation of household energy-saving lamps, conversion rate is up to 100%, with no other by-products.