Sethi Subrat, Jana Narayan Ch, Behera Sourav, Behera Rakesh R, Bagh Bidraha
School of Chemical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute, Bhubaneswar, PO Bhimpur-Padanpur, Via Jatni, Khurda, Odisha 752050, India.
ACS Omega. 2022 Dec 21;8(1):868-878. doi: 10.1021/acsomega.2c06231. eCollection 2023 Jan 10.
Two air-stable copper(I)-halide coordination polymers and with NNS and NNO ligand frameworks were synthesized and successfully utilized as efficient catalysts in an important organic reaction, namely, copper-catalyzed azide-alkyne cycloaddition, which is generally conducted in a mixture of water and organic solvents. The azide-alkyne "click" reaction was successfully conducted in pure water at r.t. under aerobic conditions. Other green solvents, including ethanol and glycerol, were also effectively used. Finally, deep eutectic solvents as green and sustainable reaction media were successfully utilized. In deep eutectic solvents, complete conversion with excellent isolated yield was achieved in a short period of time (1 h) with low catalyst loading (1 mol %) at r.t. Full conversion could also be achieved within 24 h with ppm-level (50 ppm) catalyst loading at 70 °C. Optimized reaction conditions were used for the syntheses of a large number of 1,4-disubstituted 1,2,3-triazoles with various functionalities. Triazole products were easily isolated by simple filtration. The reaction media, such as water and deep eutectic solvents, were recovered and recycled in three consecutive runs. The limited waste production is reflected in a very low -factor (0.3-2.8). Finally, the CHEM21 green metrics toolkit was employed to evaluate the sustainability credentials of different optimized protocols in various green solvents such as water, ethanol, glycerol, and deep eutectic solvents.
合成了两种具有NNS和NNO配体框架的空气稳定的卤化亚铜（I）配位聚合物，并成功地将其用作一种重要有机反应——铜催化的叠氮化物-炔烃环加成反应中的高效催化剂，该反应通常在水和有机溶剂的混合物中进行。叠氮化物-炔烃“点击”反应在室温有氧条件下于纯水中成功进行。其他绿色溶剂，包括乙醇和甘油，也得到了有效利用。最后，成功地利用了深共熔溶剂作为绿色且可持续的反应介质。在深共熔溶剂中，室温下以低催化剂负载量（1 mol%）在短时间内（1小时）实现了完全转化并获得了优异的分离产率。在70℃下以ppm级（50 ppm）催化剂负载量在24小时内也可实现完全转化。优化的反应条件用于合成大量具有各种官能团的1,4-二取代-1,2,3-三唑。三唑产物通过简单过滤即可轻松分离。反应介质，如水和深共熔溶剂，经过三次连续运行后被回收并循环使用。有限的废物产生体现在非常低的E-因子（0.3 - 2.8）上。最后，采用CHEM21绿色指标工具包来评估在水、乙醇、甘油和深共熔溶剂等各种绿色溶剂中不同优化方案的可持续性资质。
