Conditions and Edges for the Photochemical Generation of Short-Lived Aryl Cations: A Computational Approach

Abstract

A DFT investigation on the conditions required for the photochemical generation of triplet aryl cations from differently para-substituted aryl halides has been carried out. The results showed a correlation between the energy change associated with the Ar–X bond heterolytic cleavage and the substituent Hammett–Brown constant (σ_p ⁺). The method provides a means to predict the viability of the ArS_N1 photosubstitution reaction.

Key words

phenyl cations - metal-free arylation - photochemical activation - aryl halides - Hammett–Brown constants

• References and Notes

• 1 Ackermann L. In Modern Arylation Methods . Ackermann L. Wiley-VCH; Weinheim: 2009: 1
• 2 Modern Arylation Methods . Ackermann L. Wiley-VCH; Weinheim: 2009
• 3 Arvela RK, Leadbeater NF, Sangi MS, Williams VA, Granados P, Singer RD. J. Org. Chem. 2005; 70: 161
• 4 Magano J, Dunetz JR. Chem. Rev. 2011; 111: 2177

See for recent examples:
• 5a Prüger P, Hofmeister GE, Jacobsen CB, Alberg DG, Nielsen M, Jørgensen KA. Chem. Eur. J. 2010; 16: 3783
• 5b Liu H, Yin B, Gao Z, Li Y, Jiang H. Chem. Commun. 2012; 48: 2033
• 5c Ackermann L, Dell’Acqua M, Fenner S, Vicente R, Sandmann R. Org. Lett. 2011; 13: 2358
• 5d Gong-Qiang LiG.-Q, Gao H, Keene G, Devonas M, Ess DH, Kürti L. J. Am. Chem. Soc. 2013; 135: 7414
• 6 See for reviews: Rossi RA, Pierini AB, Peñéñory AB. Chem. Rev. 2003; 103: 71

See for reviews:
• 7a Shirakawa E, Hayashi T. Chem. Lett. 2012; 41: 130
• 7b Studer A, Curran DP. Nat. Chem. 2014; 6: 765
• 7c Sun C.-L, Shi ZJ. Chem. Rev. 2014; 114: 9219
• 8 Xu Q.-L, Gao H, Yousufuddin M, Ess DH, Kürti L. J. Am. Chem. Soc. 2013; 135: 14048
• 9 Yuan Y, Thom I, Kim SH, Chen D, Beyer A, Bonnamour J, Zuidema E, Chang S, Bolm C. Adv. Synth. Catal. 2010; 352: 2892
• 10 Bhunia A, Yetra SR, Biju AT. Chem. Soc. Rev. 2012; 41: 3140
• 11a Castro S, Fernández JJ, Vicente R, Fañanás FJ, Rodríguez F. Chem. Commun. 2012; 48: 9089
• 11b Merritt EA, Olofsson B. Angew. Chem. Int. Ed. 2009; 48: 9052
• 12a Photochemically Generated Intermediates in Synthesis . Albini A, Fagnoni M. John Wiley and Sons; Hoboken: 2013
• 12b Dichiarante V, Protti S. In CRC Handbook of Organic Photochemistry and Photobiology. Griesbeck AG, Oelgemoeller M, Ghetti A. Taylor and Francis; Boca Raton: 2012. 3rd ed., 212
• 13 Hari DP, Schroll P, König B. J. Am. Chem. Soc. 2012; 134: 2958
• 14a Fagnoni M, Albini A. Acc. Chem. Res. 2005; 38: 713
• 14b Dichiarante V, Fagnoni M. Synlett 2008; 787
• 15a Previtali CM, Ebbesen TW. J. Photochem. 1985; 30: 259
• 15b Han K.-L, He G.-Z. J. Photochem. Photobiol., C 2007; 8: 55
• 16a Dichiarante V, Dondi D, Protti S, Fagnoni M, Albini A. J. Am. Chem. Soc. 2007; 129: 5605 ; corrigendum: 2007, 129, 11662
• 16b Protti S, Dichiarante V, Dondi D, Fagnoni M, Albini A. Chem. Sci. 2012; 3: 1330
• 17 Lazzaroni S, Protti S, Fagnoni M, Albini A. J. Photochem. Photobiol., A 2010; 210: 140
• 18 Raviola C, Protti S, Ravelli D, Mella M, Albini A, Fagnoni M. J. Org. Chem. 2012; 77: 9094
• 19a Ravelli D, Protti S, Fagnoni M, Albini A. J. Org. Chem. 2013; 78: 3814
• 19b Protti S, Ravelli D, Mannucci B, Albini A, Fagnoni M. Angew. Chem. Int. Ed. 2012; 51: 8577

See for recent examples:
• 20a Qrareya H, Raviola C, Protti S, Fagnoni M, Albini A. J. Org. Chem. 2013; 78: 6016
• 20b Raviola C, Canevari V, Protti S, Albini A, Fagnoni M. Green Chem. 2013; 15: 2704
• 20c Protti S, Fagnoni M, Albini A. J. Org. Chem. 2012; 77: 6473
• 20d Lazzaroni S, Protti S, Fagnoni M, Albini A. Org. Lett. 2009; 11: 349

Several computational investigations have been carried out see for instance:
• 20e Bondarchuk SV, Minaev BF. J. Phys. Chem. A 2014; 118: 3201
• 20f Lazzaroni S, Dondi D, Fagnoni M, Albini A. J. Org. Chem. 2010; 75: 315
• 21a Fagnoni M, Mella M, Albini A. Org. Lett. 1999; 1: 1299
• 21b Guizzardi B, Mella M, Fagnoni M, Albini A. J. Org. Chem. 2003; 68: 1067
• 21c Guizzardi B, Mella M, Fagnoni M, Albini A. Chem. Eur. J. 2003; 9: 1549
• 21d Dichiarante V, Fagnoni M, Albini A. Chem. Commun. 2006; 3001
• 22a Freccero M, Fagnoni M, Albini A. J. Am. Chem. Soc. 2003; 125: 13182
• 22b Guizzardi B, Mella M, Fagnoni M, Freccero M, Albini A. J. Org. Chem. 2001; 66: 6353
• 23 Barone V, Cossi M. J. Phys. Chem. A 1998; 102: 1995
• 24 Grein F. J. Phys. Chem. 2002; 106: 3823
• 25 Hansch C, Leo A, Taft RW. Chem. Rev. 1991; 91: 165
• 26a Creary X, Underiner TL. J. Org. Chem. 1985; 50: 2165
• 26b Creary X. Chem. Rev. 1991; 91: 1625
• 27 In this case the photoreactivity of the substituent G should be taken into account in the assessment of the process, e.g., as in the case of aryl boronic acids, only few information have been reported for the corresponding boronate esters, see: Cameron KS, Pincock AL, Pincock JA, Thompson A. J. Org. Chem. 2004; 69: 4954