Zhang Jun, Wang Xuefeng, Kuang Yunyan, Wu Jie
Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai 200438, China.
School of Pharmaceutical and Materials Engineering, Taizhou University, 1139 Shifu Avenue, Zhejiang 318000, China.
iScience. 2020 Nov 27;23(12):101872. doi: 10.1016/j.isci.2020.101872. eCollection 2020 Dec 18.
As a privileged motif, tetrazoles can be widely found in pharmaceuticals and materials science. Herein, a five-component reaction of cycloketone oxime esters, alkynes, DABCO·(SO), and two molecules of trimethylsilyl azide under iron catalysis is developed, giving rise to a range of cyano-containing sulfonylated tetrazoles in moderate to good yields. This multicomponent reaction exhibits excellent selectivity and enables the formation of multiple new chemical bonds in one pot. A possible mechanism involving azidosulfonylation of alkynes, C-C bond cleavage of both cycloketone oxime esters and alkynes, and [3 + 2] cycloaddition of trimethylsilyl azide and the nitrilium cation intermediate is proposed. Additionally, the potential of terminal alkynes acting as powerful synthons for the synthesis of tetrazoles in a radical initiated process is demonstrated for the first time.
作为一种特殊的结构单元，四氮唑广泛存在于药物和材料科学领域。在此，我们开发了一种在铁催化下，环酮肟酯、炔烃、DABCO·(SO)与两分子三甲基硅基叠氮的五组分反应，可中等至良好产率地生成一系列含氰基的磺酰化四氮唑。该多组分反应具有出色的选择性，能够在一锅反应中形成多个新的化学键。我们提出了一种可能的机理，涉及炔烃的叠氮磺酰化、环酮肟酯和炔烃的C-C键断裂，以及三甲基硅基叠氮与腈鎓阳离子中间体的[3 + 2]环加成反应。此外，首次证明了末端炔烃在自由基引发过程中作为合成四氮唑的强大合成子的潜力。
