S1 Supporting Information In Situ Generation of Nitrile Oxides from Copper Carbene and tert-Butyl Nitrite: Synthesis of Fully Substituted Isoxazoles Rongxiang Chen, a Abosede Adejoke Ogunlana, a Shangwen Fang, a Wenhao Long, a Hongmei Sun, a Xiaoguang Bao* a and Xiaobing Wan* a a Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China Email: wanxb@suda.edu.cn; xgbao@suda.edu.cn List of contents General information……………………………………………….…………….S2 General procedures for reactions……………………………..………………...S2 Mechanistic studies………………………………………………….….………..S5 X-ray diffraction analysis of compound 4f and 5d………………..……………S7 Compound characterizations……………………………………..……………...S11 References……………………………………...…………………..…………...…S19 NMR spectroscopic data for products…………………………………..………S21 MS spectroscopic data for products……………………………………...………S49 Cartesian coordinates and energies……………………………..……………….S75 Electronic Supplementary Material (ESI) for Organic & Biomolecular Chemistry. This journal is © The Royal Society of Chemistry 2018