Efficient and Selective Methane Borylation Through Pore Size Tuning of Hybrid Porous Organic‐Polymer‐Based Iridium Catalysts

• Published in: Angewandte Chemie International Edition
• Main Authors: Chen, Qi, Dong, Anwang, Wang, Dongxu, Qiu, Lu, Ma, Chunxin, Yuan, Yihui, Zhao, Yunpeng, Jia, Na, Guo, Zhanhu, Wang, Ning
• Other Authors: National Natural Science Foundation of China
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2019
• Subjects: General Chemistry; Catalysis; Methane hydrate
• Online Access: http://dx.doi.org/10.1002/anie.201906350; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fanie.201906350; https://onlinelibrary.wiley.com/doi/pdf/10.1002/anie.201906350; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/anie.201906350

Abstract As a new energy source that could replace petroleum, the global reserves of methane hydrate (combustible ice) are estimated to be approximately 20 000 trillion cubic meters. A large amount of methane hydrate has been found under the seabed, but the transportation and storage of methane gas far from coastlines are technically unfeasible and expensive. The direct conversion of methane into value‐added chemicals and liquid fuels is highly desirable but remains challenging. Herein, we prepare a series of iridium complexes based on porous polycarbazoles with high specific areas and good thermochemical stabilities. Through structure tuning we optimized their catalytic activities for the selective monoborylation of methane. One of these catalysts (CAL‐3‐Ir) can produce methyl boronic acid pinacol ester (CH 3 Bpin) in 29 % yield in 9 h with a turnover frequency (TOF) of approximately 14 h −1 . Because its pore sizes favor monoborylated products, it has a high chemoselectivity for monoborylation (CH 3 Bpin:CH 2 (Bpin) 2 =16:1).