A Bond-Weakening Borinate Catalyst that Improves the Scope of the Photoredox α-C–H Alkylation of Alcohols

Dedicated to the late Professor Dieter Enders

Abstract

The development of catalyst-controlled, site-selective C(sp³)–H functionalization reactions is currently a major challenge in organic synthesis. In this paper, a novel bond-weakening catalyst that recognizes the hydroxy group of alcohols through formation of a borate is described. An electron-deficient borinic acid–ethanolamine complex enhances the chemical yield of the α-C–H alkylation of alcohols when used in conjunction with a photoredox catalyst and a hydrogen atom transfer catalyst under irradiation with visible light. This ternary hybrid catalyst system can, for example, be applied to functional-group-enriched­ peptides.

Key words

photoredox catalyst - hydrogen atom transfer catalyst - boron­ - bond-weakening - C–H functionalization

• References

• 1a Yamaguchi J, Yamaguchi AD, Itami K. Angew. Chem. Int. Ed. 2012; 51: 8960
• 1b Wencel-Delord J, Glorius F. Nat. Chem. 2013; 5: 369
• 1c Cernak T, Dykstra KD, Tyagarajan S, Vachal P, Krska SW. Chem. Soc. Rev. 2016; 45: 546

For recent reviews on C(sp³)–H functionalization reactions, see:
• 2a He J, Wasa M, Chan KS. L, Shao Q, Yu J.-Q. Chem. Rev. 2017; 117: 8754
• 2b Lu Q, Glorius F. Angew. Chem. Int. Ed. 2017; 56: 49
• 2c Liu C, Yuan J, Gao M, Tang S, Li W, Shi R, Lei A. Chem. Rev. 2015; 115: 12138
• 2d Xie J, Pan C, Abdukader A, Zhu C. Chem. Soc. Rev. 2014; 43: 5245
• 2e Gensch T, Hopkinson MN, Glorius F, Wencel-Delord J. Chem. Soc. Rev. 2016; 45: 2900
• 2f Matsui JK, Lang SB, Heitz DR, Molander GA. ACS Catal. 2017; 7: 2563
• 2g Yi H, Zhang G, Wang H, Huang Z, Wang J, Singh AK, Lei A. Chem. Rev. 2017; 117: 9016
• 2h Chen Z, Rong M.-Y, Nie J, Zhu X.-F, Shi B.-F, Ma J.-A. Chem. Soc. Rev. 2019; 48: 4921
• 3 Lovering F, Bikker J, Humblet C. J. Med. Chem. 2009; 52: 6752

For reviews on C(sp³)–H functionalization reactions via the HAT mechanism under irradiation with visible light, see:
• 4a Shaw MH, Twilton J, MacMillan DW. C. J. Org. Chem. 2016; 81: 6898
• 4b Capaldo L, Ravelli D. Eur. J. Org. Chem. 2017; 2056
• 4c Hu X.-Q, Chen J.-R, Xiao W.-J. Angew. Chem. Int. Ed. 2017; 56: 1960
• 5a Tanaka H, Sakai K, Kawamura A, Oisaki K, Kanai M. Chem. Commun. 2018; 54: 3215
• 5b Wakaki T, Sakai K, Enomoto T, Kondo M, Masaoka S, Oisaki K, Kanai M. Chem. Eur. J. 2018; 24: 8051
• 5c Sakai K, Oisaki K, Kanai M. Adv. Synth. Catal. 2020; 362: 337
• 5d Kato S, Saga Y, Kojima M, Fuse H, Matsunaga S, Fukatsu A, Kondo M, Masaoka S, Kanai M. J. Am. Chem. Soc. 2017; 139: 2204
• 5e Fuse H, Kojima M, Mitsunuma H, Kanai M. Org. Lett. 2018; 20: 2042
• 6a Estes DP, Grills DC, Norton JR. J. Am. Chem. Soc. 2014; 136: 17362
• 6b Roth JP, Mayer JM. Inorg. Chem. 1999; 38: 2760
• 6c Wu A, Mayer JM. J. Am. Chem. Soc. 2008; 130: 14745
• 6d Manner VM, Mayer JM. J. Am. Chem. Soc. 2009; 131: 9874
• 6e Jonas RT, Stack TD. P. J. Am. Chem. Soc. 1997; 119: 8566
• 6f Semproni SP, Milsmann C, Chirik PJ. J. Am. Chem. Soc. 2014; 136: 9211
• 6g Milsmann C, Semproni SP, Chirik PJ. J. Am. Chem. Soc. 2014; 136: 12099
• 6h Bezdek MJ, Guo S, Chirik PJ. Science 2016; 354: 730
• 6i Fang H, Ling Z, Lang K, Brothers PJ, de Bruin B, Fu X. Chem. Sci. 2014; 5: 916
• 6j Miyazaki S, Kojima T, Mayer JM, Fukuzumi S. J. Am. Chem. Soc. 2009; 131: 11615
• 6k Resa S, Millán A, Fuentes N, Crovetto L, Marcos ML, Lezama L, Choquesillo-Lazarte D, Blanco V, Campaña AG, Cárdenas DJ, Cuerva JM. Dalton Trans. 2019; 48: 2179
• 7a Spiegel DA, Wiberg KB, Schacherer LN, Medeiros MR, Wood JL. J. Am. Chem. Soc. 2005; 127: 12513
• 7b Pozzi D, Scanlan EM, Renaud P. J. Am. Chem. Soc. 2005; 127: 14204
• 7c Chciuk TV, Flowers RA. II. J. Am. Chem. Soc. 2015; 137: 11526
• 8 Tarantino KT, Miller DC, Callon TA, Knowles RR. J. Am. Chem. Soc. 2015; 137: 6440
• 9a Jeffrey JL, Terrett JA, MacMillan DW. C. Science 2015; 349: 1532
• 9b Wan IC (S.), Witte MD, Minnaard AJ. Chem. Commun. 2017; 53: 4926
• 9c Wang Y, Carder HM, Wendlandt AE. Nature 2020; 578: 403
• 9d For related discussions on the bond-weakening of alcohols through hydrogen bonding, see: Gawlita E, Lantz M, Paneth P, Bell AF, Tonge PJ, Anderson VE. J. Am. Chem. Soc. 2000; 122: 11660
• 10a Dimakos V, Su HY, Garrett GE, Taylor MS. J. Am. Chem. Soc. 2019; 141: 5149
• 10b Dimakos V, Gorelik D, Su HY, Garrett GE, Hughes G, Shibayama H, Taylor MS. Chem. Sci. 2020; 11: 1531
• 11 Perozzi EF, Martin JC. J. Am. Chem. Soc. 1979; 101: 1591
• 12 For details, see the Supporting Information.
• 13 Lowry MS, Goldsmith JI, Slinker JD, Rohl R, Pascal RA, Malliaras GG, Bernhard S. Chem. Mater. 2005; 17: 5712

For representative examples of quinuclidine acting as a HAT catalyst, see:
• 14a Shaw MH, Shurtleff VW, Terrett JA, Cuthbertson JD, MacMillan DW. C. Science 2016; 352: 1304
• 14b Le C, Liang Y, Evans RW, Li X, MacMillan DW. C. Nature 2017; 547: 79
• 14c Zhang X, MacMillan DW. C. J. Am. Chem. Soc. 2017; 139: 11353
• 15 Lima F, Sharma UK, Grunenberg L, Saha D, Johannsen S, Sedelmeier J, Van der Eycken EV, Ley SV. Angew. Chem. Int. Ed. 2017; 56: 15136
• 16 Ishihara K, Yamamoto H. Eur. J. Org. Chem. 1999; 527
• 17a Farfán N, Castillo D, Joseph-Nathan P, Contreras R, Szetpály Lv. J. Chem. Soc., Perkin Trans. 2 1992; 527
• 17b Marciasini L, Cacciuttolo B, Vaultier M, Pucheault M. Org. Lett. 2015; 17: 3532
• 18 Joshi-Pangu A, Lévesque F, Roth HG, Oliver SF, Campeau L.-C, Nicewicz D, DiRocco DA. J. Org. Chem. 2016; 81: 7244
• 19 Fukuzumi S, Kotani H, Ohkubo K, Ogo S, Tkachenko NV, Lemmetyinen H. J. Am. Chem. Soc. 2004; 126: 1600
• 20 Choi GJ, Zhu Q, Miller DC, Gu CJ, Knowles RR. Nature 2016; 539: 268
• 21 Yang H.-B, Feceu A, Martin DB. C. ACS Catal. 2019; 9: 5708
• 22 Mukherjee S, Maji B, Tlahuext-Aca A, Glorius F. J. Am. Chem. Soc. 2016; 138: 16200
• 23 The C–H alkylation of 2j and 2k without borinate catalyst 6j proceeded in yields that were too low to determine the site-selectivity.
• 24 Nelsen SF, Hintz PJ. J. Am. Chem. Soc. 1972; 94: 7114
• 25 Liu W.-Z, Bordwell FG. J. Org. Chem. 1996; 61: 4778
• 26 The increase in the chemical yield may also partially originate from electrostatic interactions between the anionic borate and the quinuclidinium radical cation. For a related discussion, see: Ye J, Kalvet I, Schoenebeck F, Rovis T. Nat. Chem. 2018; 10: 1037