Please use this identifier to cite or link to this item:
Title: Expedient synthesis of E-hydrazone esters and 1H-indazole scaffolds through heterogeneous single-atom platinum catalysis
Authors: Liu, C. 
Chen, Z. 
Yan, H. 
Xi, S.
Yam, K.M. 
Gao, J.
Du, Y.
Li, J. 
Zhao, X. 
Xie, K.
Xu, H. 
Li, X. 
Leng, K. 
Pennycook, S.J. 
Liu, B.
Zhang, C. 
Koh, M.J. 
Loh, K.P.
Issue Date: 2019
Publisher: American Association for the Advancement of Science
Citation: Liu, C., Chen, Z., Yan, H., Xi, S., Yam, K.M., Gao, J., Du, Y., Li, J., Zhao, X., Xie, K., Xu, H., Li, X., Leng, K., Pennycook, S.J., Liu, B., Zhang, C., Koh, M.J., Loh, K.P. (2019). Expedient synthesis of E-hydrazone esters and 1H-indazole scaffolds through heterogeneous single-atom platinum catalysis. Science Advances 5 (12) : eaay1537. ScholarBank@NUS Repository.
Rights: Attribution-NonCommercial 4.0 International
Abstract: Unprotected E-hydrazone esters are prized building blocks for the preparation of 1H-indazoles and countless other N-containing biologically active molecules. Despite previous advances, efficient and stereoselective synthesis of these compounds remains nontrivial. Here, we show that Pt single atoms anchored on defect-rich CeO2 nanorods (Pt1/CeO2), in conjunction with the alcoholysis of ammonia borane, promotes exceptionally E-selective hydrogenation of ?-diazoesters to afford a wide assortment of N-H hydrazone esters with an overall turnover frequency of up to 566 hours?1 upon reaction completion. The ?-diazoester substrates could be generated in situ from readily available carboxylic esters in one-pot hydrogenation reaction. Utility is demonstrated through concise, scalable synthesis of 1H-indazole–derived pharmaceuticals and their 15N-labeled analogs. The present protocol highlights a key mechanistic nuance wherein simultaneous coordination of a Pt site with the diazo N=N and ester carbonyl motifs plays a central role in controlling stereoselectivity, which is supported by density functional theory calculations. Copyright © 2019 The Authors
Source Title: Science Advances
ISSN: 23752548
DOI: 10.1126/sciadv.aay1537
Rights: Attribution-NonCommercial 4.0 International
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
10_1126_sciadv_aay1537.pdf1.2 MBAdobe PDF



Google ScholarTM



This item is licensed under a Creative Commons License Creative Commons