Homolysis/mesolysis of alkoxyamines activated by chemical oxidation and photochemical-triggered radical reactions at room temperature

Abstract

Instantaneous and spontaneous room temperature C–ON bond mesolysis of alkoxyamines triggered by chemical oxidation.

Stereochemistry-Induced Discrimination in Reaction Kinetics of Photo-RAFT Initialization

“…It is well-known that different substitutions (primary, second vs tertiary carbon) of R groups in NMP and ATRP initiators have significant effects on the activation rate coefficients. − A penultimate unit effect in NMP and ATRP initiators (the initiators have identical terminal units but different penultimate units) has been comprehensively investigated on their activation rates by using experimental analysis and simulation modeling. − Meanwhile, the effects of stereochemical structures on the activation kinetics in NMP and ATRP have also been studied with considerable efforts. Matyjaszewski and co-workers synthesized a series of model dimeric alkyl bromide initiators with diverse combinations of methyl acrylate (MA), methyl methacrylate (MMA), and tert -butyl acrylate ( t BA), which have two diastereomers in most cases.…”

Synthetic Electrochemistry Enabled Esterification via Oxidative Mesolytic Cleavage of Alkoxyamines

“…General Methods and Materials. 1 H and 13 C spectra were recorded on a Bruker 400 MHz spectrometer. Chemical shifts were reported relative to those of CDCl 3 (7.26 ppm) for 1 H and CDCl 3 (77.0 ppm) for 13 C. Flash column chromatography was performed on silica gel 60 (230−400 mesh).…”

“…13 13 Flash column chromatography (2−5% EtOAc/hexanes) provided 3b as a colorless oil (18.7 mg, 78% yield). 1 H NMR (400 MHz, CDCl 3 ) δ = 7.99 (m, 2H), 7.46 (m, 2H), 7.38 (m, 2H), 7.31 (m, 1H), 7.25 (m, 2H), 6.14 (q, J = 8 Hz, 1H), 2.43 (s, 3H), 1.69 (d, J = 8 Hz, 3H); 13 C{ 1 H} NMR (101 MHz, CDCl 3 ) δ = 165.9, 143.6, 142.0, 129.7, 129.0, 128.5, 127.8, 126.0, 72.7, 22.4, 21.6; IR cm −1 2978, 2927, 2900, 2856, 2821, 1716, 1625, 1615, 1496, 1454, 1270, 1177, 1104, 1062, 1018, 755, 700…”

“…14 Flash column chromatography (2−5% EtOAc/hexanes) to provide 3c as a colorless oil (18.0 mg, 75% yield). 1 H NMR (400 MHz, CDCl 3 ) δ = 7.91 (m, 2H), 7.48−7.46 (m, 2H) 7.41−7.29 (m, 5H), 6.15 (q, J = 8 Hz, 1H), 2.43 (s, 3H), 1.69 (d, J = 8 Hz, 3H); 13 1-Phenylethyl 4-Nitrobenzoate (3g). 14 Flash column chromatography (2−5% EtOAc/hexanes) provided 3g as a colorless oil (17.6 mg, 65% yield).…”

“…Colorless oil. 1 H NMR (400 MHz, CDCl 3 ) δ = 7.60−7.20 (m, 7H), 6.53−6.52 (m, 1H), 6.14 (q, J = 8 Hz, 1H), 1.68 (d, J = 8 Hz, 3H); 13 C{ 1 H} NMR (100 MHz, CDCl 3 ) 158.0, 146.3, 128.5, 128.0, 126.1, 117.9, 111.8, 72.9, 22.2; IR cm −1 2978, 2929, 2887, 2858, 1733, 1717, 1580, 1476, 1454, 1399, 1292, 1180, 1120, 1067, 1016, 943, 761, 700. HRMS (ESI) m/z: [M + H] + calcd for C 13 H 13 O 3 , 217.0859; found, 217.0865.…”