TY - JOUR
T1 - Photochemically Activated Dimagnesium(I) Compounds
T2 - Reagents for the Reduction and Selective C−H Bond Activation of Inert Arenes
AU - Jones, Dafydd D.L.
AU - Douair, Iskander
AU - Maron, Laurent
AU - Jones, Cameron
PY - 2021/3/22
Y1 - 2021/3/22
N2 - The photochemical activation of dimagnesium(I) compounds, and subsequent high yielding, regioselective reactions with inert arenes are reported. Irradiating benzene solutions of [{(ArNacnac)Mg}2] (ArNacnac=[HC(MeCNAr)2]−; Ar=2,6-diisopropylphenyl (Dip) or 2,4,6-tricyclohexylphenyl (TCHP)) with blue or UV light, leads to double reduction of benzene and formation of the “Birch-like” cyclohexadienediyl bridged compounds, [{(ArNacnac)Mg}2(μ-C6H6)]. Irradiation of [{(DipNacnac)Mg}2] in toluene, and each of the three isomers of xylene, promoted completely regio- and chemo-selective C−H bond activations, and formation of [(DipNacnac)Mg(Ar′)] (Ar′=meta-tolyl; 2,3-, 3,5- or 2,5-dimethylphenyl), and [{(DipNacnac)Mg(μ-H)}2]. Fluorobenzene was cleanly defluorinated by photoactivated [{(DipNacnac)Mg}2], leading to biphenyl and [{(DipNacnac)Mg(μ-F)}2]. Computational studies suggest all reactions proceed via photochemically generated magnesium(I) radicals, which reduce the arene substrate, before C−H or C−F bond activation processes occur.
AB - The photochemical activation of dimagnesium(I) compounds, and subsequent high yielding, regioselective reactions with inert arenes are reported. Irradiating benzene solutions of [{(ArNacnac)Mg}2] (ArNacnac=[HC(MeCNAr)2]−; Ar=2,6-diisopropylphenyl (Dip) or 2,4,6-tricyclohexylphenyl (TCHP)) with blue or UV light, leads to double reduction of benzene and formation of the “Birch-like” cyclohexadienediyl bridged compounds, [{(ArNacnac)Mg}2(μ-C6H6)]. Irradiation of [{(DipNacnac)Mg}2] in toluene, and each of the three isomers of xylene, promoted completely regio- and chemo-selective C−H bond activations, and formation of [(DipNacnac)Mg(Ar′)] (Ar′=meta-tolyl; 2,3-, 3,5- or 2,5-dimethylphenyl), and [{(DipNacnac)Mg(μ-H)}2]. Fluorobenzene was cleanly defluorinated by photoactivated [{(DipNacnac)Mg}2], leading to biphenyl and [{(DipNacnac)Mg(μ-F)}2]. Computational studies suggest all reactions proceed via photochemically generated magnesium(I) radicals, which reduce the arene substrate, before C−H or C−F bond activation processes occur.
KW - arene reduction
KW - C−H activation
KW - DFT calculations
KW - magnesium(I)
KW - photochemistry
UR - http://www.scopus.com/inward/record.url?scp=85101300768&partnerID=8YFLogxK
U2 - 10.1002/anie.202017126
DO - 10.1002/anie.202017126
M3 - Article
AN - SCOPUS:85101300768
SN - 1433-7851
VL - 60
SP - 7087
EP - 7092
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 13
ER -