Catalyst-Free Regioselective Hydrostannation of Arynes

Abstract

We report the first regioselective hydrostannation of an aryne. Excellent yields were achieved under mild room temperature conditions without the use of additives or catalysts. Preliminary investigations into the effects of substituents have been conducted, revealing impressive levels of regiochemical control. The method also offers a unique route to access 1,2-deuterated arylstannanes demonstrating the power and potential of this chemistry.

Key words

arynes - hydrostannation - catalyst-free - regioselective - deuterated 1,2-arylstannanes

References and Notes

• 1a Simmons HE. J. Am. Chem. Soc.  1960,  83:  1657 
• 1b Zhang F. Moses JE. Org. Lett.  2009,  11:  1587 
• 1c Spiteri C. Sharma P. Zhang F. Macdonald SJF. Keeling S. Moses JE. Chem. Commun.  2010,  46:  1272 
• 1d Spiteri C. Keeling S. Moses JE. Org. Lett.  2010,  12:  3368 
• 2a Jeganmohan M. Cheng C.-H. Chem. Commun.  2006,  2454 
• 2b Liu Z. Larock RC. Org. Lett.  2003,  5:  4673 
• 3a Jung ME. Lowen GT. Tetrahedron Lett.  1986,  27:  5319 
• 3b Pansegrau PD. Rieker WF. Meyers AI. J. Am. Chem. Soc.  1988,  110:  7178 
• 3c Henderson JL. Edwards AS. Greaney MF. J. Am. Chem. Soc.  2006,  128:  7426 
• For a recent review, see:
• 4a Yoshida H. Ohshita J. Kunai A. Bull. Chem. Soc. Jpn.  2010,  83:  199 
• 4b Erker G. Kropp K. J. Am. Chem. Soc.  1979,  101:  3659 
• 5a Peña D. Escudero S. Pérez D. Guitián E. Castedo L. Angew. Chem. Int. Ed.  1998,  37:  2659 ; Angew. Chem. 1998, 37, 2659
• 5b Peña D. Pérez D. Guitián E. Castedo L. Org. Lett.  1999,  1:  1555 
• 6a Liu Z. Zhang X. Larock RC. J. Am. Chem. Soc.  2005,  127:  15716 
• 6b Liu Z. Larock RC. J. Org. Chem.  2007,  72:  223 
• 6c Worlikar SA. Larock RC. J. Org. Chem.  2009,  74:  9132 
• 7a Peña D. Pérez D. Guitián E. Castedo L. J. Org. Chem.  2000,  65:  6944 
• 7b Yoshikawa E. Yamamoto Y. Angew. Chem. Int. Ed.  2000,  39:  173 
• 7c Yoshikawa E. Radhakrishnan KV. Yamamoto Y. J. Am. Chem. Soc.  2000,  122:  7280 
• 8 Chatani N. Kamitani A. Oshita M. Fukumoto Y. Murai S. J. Am. Chem. Soc.  2001,  123:  12686 
• 9a Yoshida H. Honda Y. Shirakawa E. Hiyama T. Chem. Commun.  2001,  1880 
• 9b Yoshida H. Tanino K. Ohshita J. Kunai A. Angew. Chem. Int. Ed.  2004,  116:  5162 
• 9c Yoshida H. Ikadai J. Shudo M. Ohshita J. Kunai A. J. Am. Chem. Soc.  2003,  125:  6638 
• 10a Dimopoulos P. Athlan A. Manaviazar S. George J. Walters M. Lazarides L. Aliev AE. Hale KJ. J. Org. Lett.  2005,  7:  5369 
• 10b Dimopoulos P. George J. Tocher DA. Manaviazar S. Hale KJ. Org. Lett.  2005,  7:  5377 
• 11 Zhang HX. Guibé F. Balavoine G. J. Org. Chem.  1990,  55:  1857 
• 12 For a review on hydrostannation, see: Smith ND. Mancuso J. Lautens M. Chem. Rev.  2000,  100:  3257 
• 13 During the preparation of this manuscript a communication was published also describing aryne hydrostannations: Vasantha B. Wefelscheid UK. Kazmaier U. Synlett  2011,  345 
• 14a Leopold DG. Miller AES. Lineberger WC. J. Am. Chem. Soc.  1986,  108:  1379 
• 14b Wenthold PG. Squires RR. Lineberger WC. J. Am. Chem. Soc.  1998,  120:  5279 
• 15 Orendt AM. Facelli JC. Radziszewski JG. Horton WJ. Grant DM. Michl J. J. Am. Chem. Soc.  1996,  118:  846 
• Generally, aryl n-tributylstannanes are synthesised via metal-halogen exchange or via a palladium cross-coupling reaction:
• 16a Kosugi M. Naka H. Harada S. Sano H. Migita T. Chem. Lett.  1987,  16:  1371 
• 16b Rigolet S. McCort I. Merrer YL. Tetrahedron Lett.  2002,  43:  8129 
• 16c Justicia J. Oltra JE. Cuerva JM. J. Org. Chem.  2004,  69:  5803 
• 16d Coelho AV. de Souza ALF. de Lima PG. Wardell JL. Antunes OAC. Tetrahedron Lett.  2007,  48:  7671 
• 18 The Pd(0)-catalysed dehydrogenative coupling of tributyltin hydride was confirmed as followed: A solution of Pd(OAc)₂ (0.02 equiv) and t-OcNC (0.3 equiv) in anhydrous THF (2 mL) was stirred at ambient temperature under argon for 30 min. Then Bu₃SnH was added dropwise and the reaction mixture was stirred for 3 h. Afterwards, the volatile components were evaporated and the crude mixture was purified by silica gel flash chromatography using petroleum ether (40-60 ˚C) as solvent system, affording Bu₃Sn-SnBu₃ (76%). See also: Braunstein P. Durand J. Morise X. Tiripicchio A. Ugozzoli F. Organometallics  2000,  19:  444 
• 19 Postigo A. Nudelman NS. J. Phys. Org. Chem.  2010,  23:  910 
• 20a Weissman SA. Zewge D. Chen C. J. Org. Chem.  2005,  70:  1508 
• 20b Alimardanov A. de Vondervoort LSV. de Vries AHM. de Vries JG. Adv. Synth. Catal.  2004,  346:  1812 
• 23a Liu Z. Shi F. Martinez PDG. Raminelli C. Larock RC. J. Org. Chem.  2008,  73:  219 
• 23b Shi F. Waldo JP. Chen Y. Larock RC. Org. Lett.  2008,  10:  2409 

17

The yield was based on ^¹H NMR analysis of the mixture of 2 and 3. The identification of the products was based by comparing the ^¹³C NMR analysis with literature data.^9b

21

General Procedure for the Hydrostannation of Benzyne: KF (2.0 equiv) and 18-crown-6 (2.0 equiv) were stirred in THF (2 mL) for 30 min. Then n-tributyltin hydride (1.1 equiv) was added, followed by the dropwise addition of
o-trimethylsilylphenyl triflate (0.081 mL, 0.335 mmol, 1.0 equiv). After completion of reaction (TLC) the volatile components were removed in vacuo and the crude residue was subjected to flash column chromatography (light petroleum) to give tributylphenylstannane 3 as a colourless oil (80%). IR (neat): 2957 (vs), 2926 (vs), 2871 (v), 2853 (v), 1463 (m), 1427 (m), 1376 (m), 1073 (m), 726 (s), 699 (s) cm^-¹. ^¹H NMR (400 MHz, CDCl₃): δ = 7.44-7.55 (m, 2 H), 7.32-7.37 (m, 3 H), 1.48-1.68 (m, 6 H), 1.32-1.41 (m, 6 H), 1.00-1.17 (m, 6 H), 0.92 (t, J = 7.3 Hz, 9 H). ^¹³C NMR (100 MHz, CDCl₃): δ = 142.0, 136.5, 127.9, 29.1, 27.4, 13.7, 9.5.

22

The regioselectivity of 10 was confirmed by ^¹H NMR, COSY, nOe studies and further by carrying out the reaction between 8 and Bu₃SnD, giving n-tributyl(2-deuteride-6-methoxyphenyl)stannane.