Synlett 2017; 28(19): 2604-2608
DOI: 10.1055/s-0036-1590962
cluster
© Georg Thieme Verlag Stuttgart · New York

Stereospecific Nickel-Catalyzed Borylation of Secondary Benzyl Pivalates

R. Martin-Montero
a  Institute of Chemical Research of Catalonia (ICIQ), Av. Paisos Catalans 16, 43007, Tarragona, Spain   Email: rmartinromo@iciq.es
,
T. Krolikowski
a  Institute of Chemical Research of Catalonia (ICIQ), Av. Paisos Catalans 16, 43007, Tarragona, Spain   Email: rmartinromo@iciq.es
,
C. Zarate
a  Institute of Chemical Research of Catalonia (ICIQ), Av. Paisos Catalans 16, 43007, Tarragona, Spain   Email: rmartinromo@iciq.es
,
a  Institute of Chemical Research of Catalonia (ICIQ), Av. Paisos Catalans 16, 43007, Tarragona, Spain   Email: rmartinromo@iciq.es
,
R. Martin*
a  Institute of Chemical Research of Catalonia (ICIQ), Av. Paisos Catalans 16, 43007, Tarragona, Spain   Email: rmartinromo@iciq.es
b  Catalan Institution for Research and Advanced Studies (ICREA), Passseig Lluis Companys, 23, 08010, Barcelona, Spain
› Author Affiliations
MINECO (CTQ2015-65496-R & Severo Ochoa Excellence Accreditation 2014-2018, SEV-2013-0319) and Cellex Foundation.
Further Information

Publication History

Received: 01 August 2017

Accepted after revision: 26 October 2017

Publication Date:
08 November 2017 (online)

Published as part of the Cluster C–O Activation

Abstract

A stereoselective nickel-catalyzed direct borylation of enantioenriched secondary benzyl pivalates is described. This methodology is characterized by an intriguing cooperativity of simple nickel and copper salts to promote the targeted C–B bond formation under mild reaction conditions. Unlike classical SN2-type processes, this protocol occurs with a neat retention of configuration, resulting in synthetically versatile benzyl boronic esters with excellent stereochemical fidelity.

Supporting Information

 
  • References and Notes

    • 1a Zarate C. Van Gemmeren M. Somerville RJ. Martin R. Adv. Organomet. Chem. 2016; 66: 143
    • 1b Tollefson EJ. Hanna LE. Jarvo ER. Acc. Chem. Res. 2015; 47: 2344
    • 1c Su B. Cao Z.-C. Shi Z.-J. Acc. Chem. Res. 2015; 48: 886
    • 1d Tobisu M. Chatani N. Acc. Chem. Res. 2015; 48: 1717
    • 1e Cornella J. Zarate C. Martin R. Chem. Soc. Rev. 2014; 43: 8081
    • 1f Yamaguchi J. Muto K. Itami K. Eur. J. Org. Chem. 2013; 19
    • 1g Rosen BM. Quasdorf KW. Wilson DA. Zhang N. Resmerita A.-M. Garg N. Percec V. Chem. Rev. 2011; 111: 1346

      For selected enantioselective, rather than stereospecific, cross-coupling reactions of C–O electrophiles other than particularly activated organic sulfonates, see:
    • 2a Cornella J. Jackson EP. Martin R. Angew. Chem. Int. Ed. 2015; 54: 4075
    • 2b Oelke AJ. Jianwei S. Fu GC. J. Am. Chem. Soc. 2012; 134: 2966
  • 3 Chenery AH. Kadunce NT. Reisman SE. Chem. Rev. 2015; 115: 9587
  • 4 Eliel EL. Wilen SH. Stereochemistry of Organic Compounds . John Wiley and Sons; New York: 1994
    • 5a Erickson LW. Lucas EL. Tollefson EJ. Jarvo ER. J. Am. Chem. Soc. 2016; 138: 14006
    • 5b Konev MO. Hanna LE. Jarvo ER. Angew. Chem. Int. Ed. 2016; 55: 6730
    • 5c Tollefson EJ. Dawson DD. Osborne CA. Jarvo ER. J. Am. Chem. Soc. 2014; 136: 14951
    • 5d Harris MR. Konev MO. Jarvo ER. J. Am. Chem. Soc. 2014; 136: 7825
    • 5e Yonova IM. Johnson AG. Osborne CA. Moore CE. Morrissette NS. Jarvo ER. Angew. Chem. Int. Ed. 2014; 53: 2422
    • 5f Harris MR. Hanna LE. Greene MA. Moore CE. Jarvo ER. J. Am. Chem. Soc. 2013; 135: 3303
    • 5g Taylor BL. H. Swift EC. Waetzig JD. Jarvo ER. J. Am. Chem. Soc. 2011; 133: 389
    • 6a Zhou Q. Cobb KM. Tan T. Watson MP. J. Am. Chem. Soc. 2016; 138: 12057
    • 6b Zhou Q. Srnivas HD. Zhang S. Watson MP. J. Am. Chem. Soc. 2016; 138: 11989
    • 6c Srnivas HD. Zhou Q. Watson MP. Org. Lett. 2014; 16: 3596
    • 6d Zhou Q. Srinivas HD. Dasgupta S. Watson MP. J. Am. Chem. Soc. 2013; 135: 3307

      For selected references, see:
    • 7a Zarate C. Nakajima M. Martin R. J. Am. Chem. Soc. 2017; 139: 1191
    • 7b Zarate C. Manzano R. Martin R. J. Am. Chem. Soc. 2015; 137: 6754
    • 7c Zarate CM. Martin R. J. Am. Chem. Soc. 2014; 136: 7253
    • 7d Tobisu M. Yasutome A. Yamakawa A. Yamakawa K. Shimasaki T. Chatani N. Tetrahedron 2012; 68: 5157
    • 7e Tobisu M. Shimasaki T. Chatani N. Chem. Lett. 2009; 38: 710

      For selected comprehensive reviews on C–heteroatom bond-forming reactions:
    • 8a Zhu X. Chiba S. Chem. Soc. Rev. 2016; 45: 4504
    • 8b Surry DS. Buchwald SL. Chem. Sci. 2011; 2: 27
    • 8c Catalyzed Carbon-Heteroatom Bond-Formation . Yudin AK. Wiley-VCH; Weinheim: 2010
    • 8d Hartwig JF. Nature 2008; 455: 314
  • 9 Tobisu M. Zhao J. Kinuta H. Furukawa T. Igarashi T. Chatani N. Adv. Synth. Catal. 2016; 358: 2417

    • Selected references:
    • 10a ref. 2a and 7a,b.
    • 10b Gu Y. Martin R. Angew. Chem. Int. Ed. 2017; 56: 3187
    • 10c Correa A. Martin R. J. Am. Chem. Soc. 2014; 136: 7253
    • 10d Correa A. León T. Martin R. J. Am. Chem. Soc. 2014; 136: 1062
    • 10e Alvarez-Bercedo P. Martin R. J. Am. Chem. Soc. 2010; 132: 17352
    • 10f Cornella J. Martin R. Org. Lett. 2013; 15: 6298
    • 10g Cornella J. Gómez-Bengoa E. Martin R. J. Am. Chem. Soc. 2013; 135: 1997
    • 11a Sandford C. Aggarwal VK. Chem. Commun. 2017; 53: 5481
    • 11b Hall DG. Boronic Acids . Wiley-VCH; Weinheim: 2005
  • 12 For details, see Supporting Information.
  • 13 The mass balance of the reaction accounts for the formation of 2-ethylnaphthalene via protodeborylation and the corresponding homobenzylboronic ester obtained from the putative oxidative addition species by a β-hydride elimination/migratory insertion prior C–B bond formation at the terminal position.
  • 14 The synergistic use of CuF2 and low-valent nickel species was initially demonstrated by our group when forging C–Si bonds, see ref. 7c. For the beneficial role of CsF in recent C–O bond-cleavage procedures, see: Schwarzer MC. Konno R. Hojo T. Ohtsuki A. Nakamura K. Yasutome A. Takahashi H. Shimasaki T. Tobisu M. Chatani N. Mori S. J. Am. Chem. Soc. 2017; 139: 10347

    • For recent examples of Ni/Cu cooperativity for effecting C–heteroatom bond-forming reactions, see:
    • 15a Gou L. Chatupheeraphat A. Rueping M. Angew. Chem. Int. Ed. 2016; 55: 11810
    • 15b Semba K. Ohtagaki Y. Nakao Y. Org. Lett. 2016; 18: 3956
    • 15c Pu X. Hu J. Zhao Y. Shi Z. ACS Catal. 2016; 6: 6692
  • 16 Bakshi RK. Shibata S. Chen C. Singh VK. Corey EJ. J. Am. Chem. Soc. 1987; 109: 7925
  • 17 Recovered starting material was observed when employing non-π-extended aryl pivalates.

    • For selected references limited to π-extended systems or to the presence of ortho- or para-activating groups, see:
    • 19a Guo L. Liu X. Baumann C. Rueping M. Angew. Chem. Int. Ed. 2016; 55: 15415
    • 19b Zhao Y. Snieckus V. J. Am. Chem. Soc. 2014; 136: 11224
    • 19c Yu D.-G. Shi Z.-J. Angew. Chem. Int. Ed. 2011; 50: 7097
    • 19d Tobisu M. Yamakawa K. Shimasaki T. Chatani N. Chem. Commun. 2011; 47: 2946
    • 19e Yu DG. Li BJ. Zheng SF. Guan BT. Wang BQ. Shi ZJ. Angew. Chem. Int. Ed. 2010; 49: 4566
    • 19f Alvarez-Bercedo R. Martin R. J. Am. Chem. Soc. 2010; 132: 17352
    • 19g Tobisu M. Shimasaki T. Chatani N. Angew. Chem. Int. Ed. 2008; 47: 4866
  • 20 η2-Coordination of π-extended systems to low-valent metal complexes is known to be stronger than regular arenes due to the partial preservation of the aromaticity: Bauer DJ. Krueger C. Inorg. Chem. 1977; 16: 884
  • 21 Martin R. Buchwald SL. Acc. Chem. Res. 2008; 41: 1461
  • 22 Imao D. Glasspole BW. Laberge VS. Crudden CM. J. Am. Chem. Soc. 1987; 109: 4756
    • 23a Zweifel G. Arzoumanian H. Whitney CC. J. Am. Chem. Soc. 1967; 89: 3652
    • 23b Evans A. Crawford TC. Thomas RC. Walker JA. J. Org. Chem. 1976; 41: 3947
    • 23c Sonawane RP. Jheengut V. Rabalakos C. Larouche-Gauthier R. Scott HK. Aggarwal VK. Angew. Chem. Int. Ed. 2011; 50: 3760
  • 24 (R)-1-(6-fluoronaphthalen-2-yl)ethanol (2d) – Typical ProcedureA 5 mL oven-dried screw-capped test tube containing a stirring bar was charged with the benzyl pivalate 1d (54.8 mg, 0.2 mmol). The test tube was introduced in an argon-filled glovebox where B2nep2 (67.8 mg, 0.3 mmol, 1.5 equiv), CuF2 (6 mg, 30 mol%), CsF (9.1 mg, 30 mol%), Ni(COD)2 (304 μL, 7.5 mol%, 0.05 M in toluene), PCy3 (152 μL, 7.5 mol%, 0.1 M), and toluene (1 mL) were then added sequentially. The tube with the mixture was taken out of the glovebox and stirred at 50 °C for 15 h. The mixture was then allowed to warm to room temperature, diluted with EtOAc (5 mL), and filtered through a Celite® plug, eluting with additional EtOAc (5mL). The filtrate was concentrated removing the volatiles. Then the reaction was cooled to 0 °C (water/ice bath) and BHT (ca. 1 mg) was added followed by anhydrous THF (1 mL). An ice-cold degassed mixture of 3 M NaOH (1.2 mL) and 30% aq H2O2 (0.75 mL) was added all at once. The reaction mixture was stirred at room temperature for 2 h. Then, the reaction mixture was diluted with water (4 mL) and extracted with Et2O (3 × 10 mL). The combined organic layers were washed with brine and dried over MgSO4. The filtrate was concentrated and purified by silica gel chromatography to give the title product 2d (30.5 mg, 80%) as a white solid (mp 84–86 °C). The enantiomeric excess was determined to be 65% ee (88% ees) by chiral HPLC analysis (CHIRALPAK IB, 1 mL/min, 2% EtOH/hexane, λ = 220 nm): t R (minor) = 12.4 min, t R (major) = 13.9 min. [α]D 24 = 43.2 (c 0.06, CHCl3).1H NMR (500 MHz, CDCl3): δ = 7.83–7.76 (m, 3 H), 7.53 (dd, J = 2.0 Hz, 1 H), 7.44 (dd, J = 2.6 Hz, 1 H), 7.26 (td, J = 2.6 Hz, 1 H), 5.06 (q, J = 6.4 Hz, 1 H), 1.97 (s, 1 H, OH), 1.58 (d, J = 6.4 Hz, 3 H) ppm. 13C NMR (126 MHz, CDCl3): δ = 161.8, 159.4, 142.5, 133.6, 130.3, 127.7, 124.9, 123.8, 116.6, 110.7, 70.3, 25.2 ppm. 19F NMR (376 MHz, CDCl3): δ = –115.1 ppm.