Synlett 2009(8): 1331-1335  
DOI: 10.1055/s-0028-1088131
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of 1,1-Organodiboronates via Rh(I)Cl-Catalyzed Sequential Regioselective Hydroboration of 1-Alkynes

Kohei Endo*, Munenao Hirokami, Takanori Shibata*
Department of Chemistry and Biochemistry, Advanced School of Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555, Japan
Fax: +81(3)52863487; e-Mail: kendo@aoni.waseda.jp; e-Mail: tshibata@waseda.jp;
Further Information

Publication History

Received 21 January 2009
Publication Date:
08 April 2009 (online)

Abstract

A Rh(I)Cl-DPPB-complex-catalyzed sequential hydro­boration of aryl alkynes and aliphatic alkynes was achieved. The ­reaction proceeded with almost perfect regioselectivity to afford 1,1-organodiboronate compounds in moderate to good yield.

    Reference and Notes

  • 1a Handbook of Functionalized Organometallics   Vol. 1 and 2:  Knochel P. Wiley-VCH; Weinheim: 2005. 
  • 1b Hirai A. Nakamura M. Nakamura E. J. Am. Chem. Soc.  1999,  121:  8665 
  • 1c Normant JF. Acc. Chem. Res.  2001,  34:  640 
  • 1d Dembitsky VM. Ali HA. Srebnik M. Appl. Organomet. Chem.  2003,  17:  327 
  • 2 The 1,1-organodiboronate attached to sp³-carbon center was obtained as a byproduct, see: McIsaac DI. Geier SJ. Vogels CM. Decken A. Westcott SA. Inorg. Chim. Acta  2006,  359:  2771 
  • 3 The diboration reaction of alkynylboronate or alkenylboronate was reported, which provides a mixture of 1,1,1- and 1,1,2-alkenyltriborylated or 1,1,1- and 1,1,2-alkyltriborylated compounds along with the formation of other types of diborylated compounds, see: Nguyen P. Coapes RB. Woodward AD. Taylor NJ. Burke JM. Howard JAK. Marder TB. J. Organomet. Chem.  2002,  652:  77 
  • 4a Hata T. Kitagawa H. Masai H. Kurahashi T. Shimizu M. Hiyama T. Angew. Chem. Int. Ed.  2001,  40:  790 
  • 4b Kurahashi T. Hata T. Masai H. Kitagawa H. Shimizu M. Hiyama T. Tetrahedron  2002,  58:  6381 
  • 4c Shimizu M. Nakamaki C. Shimono K. Schelper M. Kurahashi T. Hiyama T. J. Am. Chem. Soc.  2005,  127:  12506 
  • 4d Shimizu M. Schelper M. Nagao I. Shimoto K. Kurahashi T. Hiyama T. Chem. Lett.  2006,  35:  1222 
  • The hydroboration of alkynes using BH3˙THF complex was reported to give a mixture of monoborylated, 1,1-dibory-lated, and 1,2-diborylated compounds along with the formation of reduction product, see:
  • 5a Pasto DJ. J. Am. Chem. Soc.  1964,  86:  3039 
  • 5b Rao VVR. Agarwal SK. Mehrotra I. Devaprabhakara D. J. Organomet. Chem.  1979,  166: 
  • 6 The diboration reaction gave the regioisomeric mixture of products, see: Coapes RB. Souza FES. Thomas RL. Hall JJ. Marder TB. Chem. Commun.  2003,  614 
  • 7a Brown reported the sequential hydroboration of alkynes using 9-BBN to obtain 1,1-organodiborane intermediates, which was readily converted into primary alcohol via protonolysis and oxidation; see: Brown HC. Scouten CG. Liotta R. J. Am. Chem. Soc.  1979,  101:  96 
  • 7b Matteson reported the stepwise synthesis of 1,1-organo-diboronate via the hydroboration of 1-hexyne using BCl3 and TMS. The subsequent reaction with 1,3-propanediol afforded the corresponding 1,1-organodiboronate, see: Soundararajan R. Matteson DS. Organometallics  1995,  14:  4157 
  • Rh(I)-catalyzed hydroboration of alkenes, see:
  • 8a Hayashi T. In Comprehensive Asymmetric Catalysis   Vol. 1:  Jacobsen EN. Phaltz A. Yamamoto H. Springer; New York: 1999.  p.349 
  • 8b Hayashi T. Matsumoto Y. Ito Y. J. Am. Chem. Soc.  1989,  111:  3426 
  • 8c Westcott SA. Blom HP. Marder TB. Baker RT. J. Am. Chem. Soc.  1992,  114:  8863 
  • 8d Brown JM. Hulmes DE. Layzell TP. J. Chem. Soc., Chem. Commun.  1993,  1673 
  • 8e Tucker CE. Davidson J. Knochel P. J. Org. Chem.  1992,  57:  3482 
  • 8f Doucet H. Fernandez E. Layzell TP. Brown JM. Chem. Eur. J.  1999,  5:  1320 
  • 8g Chen A. Ren L. Crudden CM. J. Org. Chem.  1999,  64:  9704 
  • 8h Demay S. Volant F. Knochel P. Angew. Chem. Int. Ed.  2001,  40:  1235 
  • 8i Murata M. Kawakita K. Asana T. Watanabe S. Masuda Y. Bull. Chem. Soc. Jpn.  2002,  75:  825 
  • 8j Crudden CM. Edwards D. Eur. J. Org. Chem.  2003,  4695 
  • 8k Crudden CM. Hleba YB. Chen AC. J. Am. Chem. Soc.  2004,  126:  9200 
  • 8l Segarra AM. Daura-Oller E. Claver C. Poblet JM. Bo C. Fernández E. Chem. Eur. J.  2004,  10:  6456 
  • 8m Moteki SA. Wu D. Chandra KL. Reddy DS. Takacs JM. Org. Lett.  2006,  8:  3097 
  • 8n Carroll A.-M. O’Sullivan TP. Guiry PJ. Adv. Synth. Catal.  2005,  347:  609 
  • 8o Edwards DR. Hleba YB. Lata CJ. Calhoun LA. Crudden CM. Angew. Chem. Int. Ed.  2007,  46:  7799 
  • 9a Endo K. Hirokami M. Shibata T. Organometallics  2008,  27:  5390 
  • 9b Endo K. Hirokami M. Takeuchi K. Shibata T. Synlett  2008,  3231 
  • 10a Lee T. Baik C. Jung I. Song KH. Kim S. Kim D. Kang SO. Ko J. Organometallics  2004,  23:  4569 
  • 10b Ohmura T. Yamamoto Y. Miyaura N. J. Am. Chem. Soc.  2000,  122:  4990 
  • 11 Both of the commercially available HBpin and purified HBpin according to the literature gave the almost same results; the impurities in HBpin was suggested by: Shimada S. Batsanov AS. Howard JAK. Marder TB. Angew. Chem. Int. Ed.  2001,  40:  2168 
  • 12 The regioselectivity was confirmed by ¹H NMR, HMQC, and HMBC analyses. The crude products did not include 1,2-diboronate. The oxidation of product 2a under H2O2/NaOH conditions did not give 1-phenyl-1,2-ethanediol derived from 1,2-diboronate at all (unidentified products were obtained). The oxidation of 1,2-diboration product was reported, see: Trudeau S. Morgan JB. Shrestha M. Morken JP. J. Org. Chem.  2005,  70:  9538