To a 50 mL Schlenk tubes with a stir bar was added ethyl diazoacetate 1a (23 mg, ... The reaction mixture was stirred under argon at room temperture for 0.5 h.
Supplementary Information
Iodine catalyzed diazo activation to access radical reactivity Li et, al.
Supplementary Methods
General Information: All reagents purchased from commercial sources were used as received. The silica gel for column chromatography was supplied as 300–400 meshes. The 1H and 13C NMR spectra were recorded on a Bruker AVANCE III spectrometer and are referenced to the residual solvent signals (7.26 ppm for 1H and 77.0 ppm for 13C in CDCl3, 2.50 ppm for 1H and 39.5 ppm for
13
C in d6-DMSO). The HRMS spectra were recorded on a Bruker
MicroTOF Q II spectrometer. EPR spectra were recorded on a Bruker A-300 spectrometer. Synthesis of Ethyl Diiodoacetate To a 50 mL Schlenk tubes with a stir bar was added ethyl diazoacetate 1a (23 mg, 0.2 mmol) and 2 mL of CDCl3. Then iodine (51 mg, 0.2 mmol) was added to the above solution. The reaction mixture was stirred under argon at room temperture for 0.5 h. The reaction was very clean by crude NMR. Ethyl 2,2-diiodoacetate 1a’ (the HNMR date is same with Lei’s paper, see ref. 35 ): 1H NMR (400 MHz, CDCl3) δ 5.34 (s, 1 H), 4.28 (q, J = 7.1 Hz, 2 H), 1.31 (t, J = 7.1 Hz, 3 H). GC-MS: 339.7, 294.8, 266.8, 212.8, 184.8, 168.8, 156.8, 139.8, 126.9.
1
Supplementary Table 1. Optimization of Reaction under Photo-initiated Conditions
Alternation from above condition none No I2 No Ru(bpy)3Cl2 White light instead of blue light In the dark Ir(dtbbpy)(bpy)2PF6 Eosin Y instead of Ru(bpy)3Cl2 10 mol% 1a’ instead of I2 10 mol% Br2 instead of I2 No I2, 1 equiv. of 1a’ instead of 1a
2a conv. 100% 0% 0% 95% 0% 75% 0% 100% 0% < 5%
3a yield 96% n.d. n.d. 85% n.d. 65% n.d. 94% n.d. trace
No I2, 1 equiv. of 1a’ instead of 1a, i-Pr2EtN (1 equiv.), Na2S2O3 (1 equiv.), MeCN instead of DCE (Suero’s conditions, ref. 22)
55%
35%
Addition of 1 equiv. of TEMPO
0%
n.d.
Reaction conditions: 1 mol% photocatalyst and 10 mol% I2 were added to a DCE solution (3 mL) of 2a (0.3 mmol) and EDA 1a (0.3 mmol), and reaction was kept under argon (degassed) at room temperature under blue light for 24 h. Conversion and yield were determined by 1H NMR spectroscopy using 1,3,5-trimethoxybenzene as internal standard. Radical Clock Experiment under Photo-initiated Conditions
To a 50 mL Schlenk tubes with a stir bar was added olefin 2b (43 mg, 0.3 mmol), diazo compound 1a (35 mg, 0.3 mmol) and 3 mL of DCE, then Ru(bpy)3Cl2.6H2O (2 mg, 0.003 mmol) and I2 (8 mg, 0.03 mmol) were added. The Schlenk tube was vacuumed and purged with argon three times before it was tightly screw-capped. The reaction mixture was stirred at room temperature under blue light for 24 h. The reaction solution was evaporated, and the residue was purified by column chromatography (PE/EA) to afford the desired product 4 in 75% yield (E/Z = 15:1). Ethyl-2,7-diiodo-4-phenylhept-4-enoate 4 (E:Z = 15:1): 1H NMR (400 MHz, CDCl3) δ 7.42–7.23 (m, 5 H), 5.68 (t, J = 7.2 Hz, 1 H), 4.20–4.03 (m, 3 H), 3.28–3.14 (m, 3 H), 2.91–2.75 (m, 1 H), 1.19 (t, J = 7.1 Hz, 3 H);
2
13
C NMR (100 MHz,
CDCl3) δ 171.0, 140.7, 139.0, 131.0, 128.6, 127.6, 126.7, 61.8, 36.5, 32.4, 18.9, 13.7, 4.9. HRMS (ESI) calcd for C15H18I2NaO2 [M+Na]+ 506.9288, found 506.9276. Supplementary
Table
2. Optimization
of Reaction
under Thermal-initiated
Conditions
entry reactant additive 2a conv. 3a yield 1 1a’ None 0% n.d. 2 1a None
