Ni-Catalyzed Reductive Carbonylation of Alkyl Halides to Form Dialkyl Ketones Using Diphenyl Oxalate as CO Surrogate

Abstract

In this work, we disclosed that diphenyl oxalate serves as a CO surrogate to enable a Ni-catalyzed carbonylation of alkyl bromides/tosylates to afford dialkyl ketones. The reaction shows broad substrate scope and good functional group tolerance.

Key words

nickel catalysis - reductive carbonylation - diphenyl oxalate - CO - dialkyl ketone

• References and Notes


Selected reviews on carbonylation reaction of alkyl halide:
• 1a Ryu I, Sonoda N. Chem. Rev. 1996; 96: 177
• 1b Ryu I, Sonoda N. Angew. Chem., Int. Ed. Engl. 1996; 35: 1050
• 1c Ryu I. Chem. Soc. Rev. 2001; 30: 16
• 1d Frish AC, Beller M. Angew. Chem. Int. Ed. 2005; 44: 674
• 1e Wu L, Fang X, Liu Q, Jackstell R, Beller M, Wu X. -F. ACS Catal. 2014; 4: 2977
• 1f Sumino S, Fusano A, Fukuyama T, Ryu I. Acc. Chem. Res. 2014; 47: 1563
• 1g Li Y, Hu Y, Wu X.-F. Chem. Soc. Rev. 2018; 47: 172
• 2a Kondo T, Tsuji Y, Watanabe Y. Tetrahedron Lett. 1988; 29: 3833
• 2b Nagahara K, Ryu I, Komatsu M, Sonoda N. J. Am. Chem. Soc. 1997; 119: 5465
• 2c Tsunoi S, Ryu I, Okuda T, Tanaka M, Komatsu M, Sonoda N. J. Am. Chem. Soc. 1998; 120: 8692

Xe irradiation carbonylation at 45 atm:
• 2d Fukuyama T, Nishitani S, Inouye T, Morimoto K, Ryu I. Org. Lett. 2006; 8: 1383
• 3 Sargent BT, Alexanian EJ. J. Am. Chem. Soc. 2016; 138: 7520
• 4a Cheng L.-J, Mankad NP. Acc. Chem. Res. 2021; 54: 2261
• 4b Cheng L.-J, Mankad NP. J. Am. Chem. Soc. 2017; 139: 10200
• 4c Cheng L.-J, Islam SM, Mankad NP. J. Am. Chem. Soc. 2018; 140: 1159
• 4d Cheng L.-J, Mankad NP. Angew. Chem. Int. Ed. 2018; 57: 10328
• 4e Pye DR, Cheng L.-J, Mankad NP. Chem. Sci. 2017; 8: 4750
• 4f Zhao S, Mankad NP. Angew. Chem. Int. Ed. 2018; 57: 5867
• 5a Li Y, Dong K, Zhu F, Wang Z, Wu X.-F. Angew. Chem. Int. Ed. 2016; 55: 7227
• 5b Li Y, Wang C, Zhu F, Wang Z, Dixneuf PH, Wu X.-F. ChemSusChem 2017; 10: 1341
• 5c Li Y, Wu X.-F. Commun. Chem. 2018; 1: 39
• 6 Chen Y, Lei S, Gong H. Org. Lett. 2019; 21: 4689

For cobalt-catalzyed carbonylation, see:
• 7a Sargent BT, Alexanian EJ. J. Am. Chem. Soc. 2017; 139: 12438
• 7b Cash D, Combs A, Dragojlovic V. Tetrahedron Lett. 2004; 45: 1143
• 8 McMahon CM, Renn MS, Alexanian EJ. Org. Lett. 2016; 18: 4148

For early examples of Ni-mediated carbonylation, see:
• 9a Heck RF. J. Am. Chem. Soc. 1963; 85: 2013
• 9b Corey EJ, Hegedus LS. J. Am. Chem. Soc. 1969; 91: 1233
• 10 Cheng R, Zhao H.-Y, Zhang S, Zhang X. ACS Catal. 2020; 10: 36
• 11a Shi R, Hu X. Angew. Chem. Int. Ed. 2019; 58: 7454

For an early example using chlorofomate as CO source, see:
• 11b Rérat A, Michon C, Agbossou-Niedercorn F, Gosmini C. Eur. J. Org. Chem. 2016; 4554
• 12 Wotal AC, Ribson RD, Weix DJ. Organometallics 2014; 33: 5874
• 13 See the Supporting Information for details.
• 14 The general procedure as well as the analytical data of a few typical compounds are summarized as follows. Method A To a flame-dried Schlenk tube was charged with alkyl bromide (0.3 mmol, 100 mol%, if it is a solid), diphenyl oxalate (73.0 mg, 0.3 mmol, 100 mol%), Zn (58 mg, 0.90 mmol, 300 mol%), NiBr₂ (6.5 mg, 0.03 mmol, 10 mol%), 4,4′-di-tert-butyl-2,2′-bipyridine (16 mg, 0.06 mmol, 20 mol%), MgCl₂ (21 mg, 0.225 mmol, 75 mol%). The tube was capped with a rubber septum. After being evacuated and backfilled nitrogen three times, alkyl bromide (0.3 mmol, 100 mol%, if it is a liquid), pyridine (12.0 mg, 0.15 mmol, 50 mol%), and/or TMSBr (23.0 mg, 0.15 mmol, 50 mol%, only for primary bromide) were added followed by addition of DMA (2.0 mL) via syringes. The reaction mixture was allowed to stir for 12 h under a N₂ atmosphere at room temperature (25 °C) and was directly loaded onto a silica column without workup. The residue was rinsed with small amount of DCM or the eluent prior to column chromatography and additional preparative TLC separation, with which the product was isolated. Method B To a flame-dried Schlenk tube was charged with alkyl 4-methylbenzenesulfonate (0.3 mmol, 100 mol%, if solid), diphenyl oxalate (73 mg, 0.3 mmol, 100 mol%), Zn (58 mg, 0.90 mmol, 300 mol%), NiI₂ (9.4 mg, 0.03 mmol, 10 mol%), 4,4′-di-tert-butyl-2,2′-bipyridine (16 mg, 0.06 mmol, 20 mol%), MgCl₂ (21 mg, 0.225 mmol, 75 mol%), KI (50 mg, 0.3 mmol, 100 mol%). The tube was capped with a rubber septum. After being evacuated and backfilled nitrogen three times, alkyl 4-methylbenzenesulfonate (0.3 mmol, 100 mol%, if it is a liquid) was added via a syringe followed by addition of DMA (2.0 mL) via a syringe. The reaction mixture was allowed to stir for 24 h under a N₂ atmosphere at 50 °C and was directly loaded onto a silica column without workup. The residue was rinsed with small amount of DCM or the eluent prior to column chromatography and additional preparative TLC separation, with which the product was isolated. 3,5-Dimethyl-1,7-diphenylheptan-4-one (3) Compound 3was prepared according to the method A using (3-bromobutyl)benzene (63.9 mg, 0.3 mmol, 100 mol%). Flash column chromatography (SiO₂: 10% ethyl acetate in petroleum ether) gave a colorless oil (37.5 mg, 0.128 mmol, 85% yield). ¹H NMR (600 MHz, CDCl₃): δ = 7.26 (td, J = 7.5, 3.4 Hz, 4 H), 7.18–7.12 (m, 6 H), 2.64 (hept, J = 6.8 Hz, 2 H), 2.58–2.52 (m, 4 H), 2.03–1.94 (m, 2 H), 1.63–1.55 (m, 2 H), 1.08 (dd, J = 10.2, 6.9 Hz, 6 H). ¹³C NMR (151 MHz, CDCl₃): δ = 217.59, 217.44, 141.88, 141.81, 128.50, 128.49, 128.42, 126.02, 126.01, 44.55, 44.46, 34.42, 33.64, 33.54, 16.71, 16.64. HRMS (ESI): m/z calcd for [M + Na⁺] (C₂₁H₂₆ONa⁺): 317.1876; found: 317.1881.
• 15 The bond energy of the C–C bond within phenyl oxalate is unknown. However, we noticed that in a discussion of radical-mediated C–C cleavage of unstrained cycloketones by Zhu et al. the energy barrier for cleavage of Csp³–Csp³ bond involving a ketyl radical is approximately 6.6 kcal/mol. We speculate that phenyl oxalate may require less energy barrier than that in Zhu’s case, which deals with Csp²–Csp³ bond cleavage, see: Wang M, Li M, Yang S, Xue X.-S, Wu X, Zhu C. Nat. Commun. 2020; 11: 672
• 16 In addition, a summary of BDE in a website suggests that the C(O)–C(O) bond within methyl oxalate possesses a BDE of 88 kcal/mol, see (accessed July 25 2021): http://iBonD.nankai.edu.cn.
• 17a Liu J, Ye Y, Sessler JL, Gong H. Acc. Chem. Res. 2020; 53: 1833
• 17b Biswas, S.; Weix, D. J. J. Am. Chem. Soc.; 2013, 135: 161, 92.