Organoborane-Catalyzed Hydrogenation of Unactivated Aldehydes with a Hantzsch Ester as a Synthetic NAD(P)H Analogue

Abstract

We have developed a method for the hydrogenation of unactivated aldehydes, using a Hantzsch ester as a NAD(P)H analogue in the presence of an electron-deficient triarylborane as a Lewis acid catalyst. Thus, tris[3,5-bis(trifluoromethyl)phenyl]borane efficiently catalyzes the hydrogenation of aliphatic aldehydes with a Hantzsch ester in 1,4-dioxane at 100 °C to give the corresponding aliphatic primary alcohols in up to 97% yield. Aromatic aldehydes also undergo the hydrogenation, even at 25 °C, to furnish the corresponding aromatic primary alcohols in up to 100% yield.

Key words

alcohols - aldehydes - hydrogenation - NADH analogues - organoboranes

• References and Notes

• 1 Berg JM, Tymoczko JL, Stryer L. Biochemistry . W. H. Freeman and Company; New York: 2002

Selected recent reviews on enzymatic reduction of carbonyl compounds, see:
• 2a Kataoka M, Kita K, Wada M, Yasohara Y, Hasegawa J, Shimizu S. Appl. Microbiol. Biotechnol. 2003; 62: 437
• 2b Jarboe LR. Appl. Microbiol. Biotechnol. 2011; 89: 249
• 2c Rabinovitch-Deere CA, Oliver JW. K, Rodriguez GM, Atsumi S. Chem. Rev. 2013; 113: 4611

Selected recent reviews on transfer hydrogenation using synthetic NADH analogues as the hydrogen donors, see:
• 3a You S.-L. Chem. Asian J. 2007; 2: 820
• 3b Ouellet SG, Walji AM, Macmillan DW. C. Acc. Chem. Res. 2007; 40: 1327
• 3c Rueping M, Sugiono E, Schoepke FR. Synlett 2010; 852
• 3d Rueping M, Dufour J, Schoepke FR. Green Chem. 2011; 13: 1084
• 3e Zheng C, You S.-L. Chem. Soc. Rev. 2012; 41: 2498
• 4 McSkimming A, Colbran SB. Chem. Soc. Rev. 2013; 42: 5439

Catalytic transfer hydrogenation of α,β-unsaturated carbonyls with a Hantzsch ester, see:
• 5a Yang JW, Hechavarria Fonseca MT, List B. Angew. Chem. Int. Ed. 2004; 43: 6660
• 5b Yang JW, Hechavarria Fonseca MT, Vignola N, List B. Angew. Chem. Int. Ed. 2005; 44: 108
• 6 Catalytic transfer hydrogenation of imines with a Hantzsch ester, see: Hoffmann S, Seayad AM, List B. Angew. Chem. Int. Ed. 2005; 44: 7424
• 7 Catalytic transfer hydrogenation of α-keto esters with a Hantzsch ester, see: Yang JW, List B. Org. Lett. 2006; 8: 5653

Lewis acid mediated hydrogenation of unactivated aldehydes with synthetic NADH analogues, see:
• 8a Zn: Creighton DJ, Sigman DS. J. Am. Chem. Soc. 1971; 93: 6314
• 8b Zn, Pb, Cb, Cu: Shirai M, Chishina T, Tanaka M. Bull. Chem. Soc. Jpn. 1975; 48: 1079
• 8c Zn: Creighton DJ, Hajdu J, Sigman DS. J. Am. Chem. Soc. 1976; 98: 4619
• 8d Mg: Ohnishi Y, Kitami M. Tetrahedron Lett. 1978; 19: 4033
• 8e Zn, Ni: Hughes M, Prince RH. J. Inorg. Nucl. Chem. 1978; 40: 703
• 8f Zn: Hood RA, Prince RH. J. Chem. Soc., Chem. Commun. 1979; 163
• 8g Mg: Mathis R, Dupas G, Decormeille A, Quéguiner G. Tetrahedron Lett. 1981; 22: 55
• 8h B, Ti, Al, Zr, Sb: Ohno A, Ishihara Y, Ushida S, Oka S. Tetrahedron Lett. 1982; 23: 3185
• 8i Mg: Dupas G, Bourguignon J, Ruffin C, Queguiner G. Tetrahedron Lett. 1982; 23: 5141
• 8j Zn: Awano H, Tagaki W. J. Chem. Soc., Chem. Commun. 1985; 994
• 8k Mg: Cazin J, Dupas G, Bourguignon J, Quéguiner G. Tetrahedron Lett. 1986; 27: 2375
• 8l Zn: Engbersen JF. J, Koudijs A, van der Plas HC. Bioorg. Chem. 1988; 16: 215
• 8m Mg, Zn, Nd, La, Eu, Al: Gelbard G, Lin J, Roques N. J. Org. Chem. 1992; 57: 1789

Brønsted acid mediated transfer hydrogenation of unactivated aldehydes with synthetic NADH analogues, see:
• 9a Shinkai S, Hamada H, Manabe O. Tetrahedron Lett. 1979; 20: 1397
• 9b Fukuzumi S, Ishikawa M, Tanaka T. J. Chem. Soc., Chem. Commun. 1985; 1069
• 9c Fukuzumi S, Ishikawa M, Tanaka T. Tetrahedron 1986; 42: 1021
• 9d Ishikawa M, Fukuzumi S. J. Chem. Soc., Chem. Commun. 1990; 1353
• 9e Kuroda K, Nagamatsu T, Yanada R, Yoneda F. J. Chem. Soc., Perkin Trans. 1 1993; 547
• 10a Deloux L, Srebnik M. Chem. Rev. 1993; 93: 763
• 10b Duggan PJ, Tyndall ED. J. Chem. Soc., Perkin Trans. 1 2002; 1325
• 10c Ishihara K In Boronic Acids . Hall DG. Wiley-VCH; Weinheim: 2005: 377-409
• 10d Dimitrijević E, Taylor MS. ACS Catal. 2013; 3: 945
• 11a Piers WE, Chivers T. Chem. Soc. Rev. 1997; 26: 345
• 11b Ishihara K, Yamamoto H. Eur. J. Org. Chem. 1999; 527
• 11c Erker G. Dalton Trans. 2005; 1883
• 11d Piers WE. Adv. Organomet. Chem. 2005; 52: 1

Very recently, Stephan and Ashley groups reported that the combination of B(C₆F₅)₃ and ethers (Et₂O, i-Pr₂O, and 1,4-dioxane) promoted the hydrogenation of ketones and limited aldehydes with H₂ gas, see:
• 12a Mahdi T, Stephan DW. J. Am. Chem. Soc. 2014; 136: 15809
• 12b Scott DJ, Fuchter MJ, Ashley AE. J. Am. Chem. Soc. 2014; 136: 15813
• 13 A review on B(C₆F₅)₃-catalyzed reduction of unsaturated compounds, see: Oestreich M, Hermeke J, Mohr J. Chem. Soc. Rev. 2015; 44: 2202
• 14 Very recently, Chatterijee and Oestreich reported the B(C₆F₅)₃-catalyzed transfer hydrogenation of imines and related heterocycles with cyclohexa-1,4-dienes, see: Chatterjee I, Oestreich M. Angew. Chem. Int. Ed. 2015; 43: 1965
• 15 Webb JD, Laberge VS, Geier SJ, Stephan DW, Crudden CM. Chem. Eur. J. 2010; 16: 4895
• 16 Herrington TJ, Thom AJ. W, White AJ. P, Ashley AE. Dalton Trans. 2012; 41: 9019
• 17 We also tested the other hydrogen donors, see the Supporting Information. The reaction with Hantzsch ester 2 provided the best result.
• 18 Typical Procedure for the Hydrogenation Reaction (10p, Scheme 3) In a glovebox, piperanal (10p, 38 mg, 0.25 mmol) and Hantzsch ester 1 (95 mg, 0.38 mmol) were added to a solution of tris[3,5-bis(trifluoromethyl)phenyl]borane (9, 8.1 mg, 0.013 mmol) in dry 1,4-dioxane (1 mL). After the reaction mixture was stirred at 25 °C for 12 h, the solvent was removed by evaporation under reduced pressure. The obtained crude material was purified by silica gel column chromatography (eluent: hexane–EtOAc, 9:1) to give piperonyl alcohol (11p, 36 mg, 94%) as a colorless solid. ¹H NMR (396 MHz, CDCl₃): δ = 2.02 (br s, 1 H, OH), 4.55 (s, 2 H, CH ₂OH), 5.94 (s, 2 H, OCH₂O), 6.77 (d, J = 8.1 Hz, 2 H, ArH), 6.80 (d, J = 8.1 Hz, 2 H, ArH), 6.85 (s, 1 H, ArH). ¹³C NMR (100 MHz, CDCl₃): δ = 65.1, 101.0, 107.8, 108.1, 120.4, 134.8, 147.0, 147.7. MS (EI): m/z = 152 [M]⁺.
• 19 The reviewer pointed out the possible participation of borohydride species in the catalytic cycle (see ref. 15). However, the preliminary NMR experiment of borane 9 with Hantzsch ester 1 did not show the formation of borohydride species. Detailed mechanistic studies including DFT calculation are under investigation and will be reported in due course.