I2-TBHP-Catalyzed Oxidative Cross-Coupling of N-Sulfonyl Hydrazones and Isocyanides to 5-Aminopyrazoles
Gopal Chandru Senadi, Wan-Ping Hu, Ting-Yi Lu, Amol Milind Garkhedkar, Jaya Kishore Vandavasi and Jeh-Jeng Wang*
*Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, No. 100, Shih-Chuan First Rd, Sanmin District, Kaohsiung City, 807, Taiwan, Email: jjwangkmu.edu.tw
G. C. Senadi, W.-P. Hu, T.-Y. Lu, A. M. Garkhedkar, J. K. Vandavasi, J.-J. Wang, Org. Lett., 2015, 17, 1521-1524.
DOI: 10.1021/acs.orglett.5b00398 (free Supporting Information)
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An I2-catalyzed oxidative cross coupling of N-sulfonyl hydrazones with isocyanides in the presence of TBHP as terminal oxidant enables the synthesis of 5-aminopyrazoles through formal [4 + 1] annulation via in situ azoalkene formation. Notable features are a metal/alkyne-free strategy, atom economy, catalytic I2, broad functional group tolerance, good reaction yields and short time.
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