Recyclable Iron/Graphite Catalyst for C-S Cross Coupling of Thiols with Aryl Halides under Ligand-Free Conditions

Abstract

A recyclable iron/graphite (Fe/Cg) catalyst for the efficient C-S cross-coupling of various iodoarenes with aromatic/­aliphatic thiols has been developed under ligand-free conditions (26 examples, up to 99% yield). The catalyst can be easily recovered and recycled up to seven cycles without loss of activity.

Key words

arylhalides - cross-coupling - recyclable catalyst - iron - thiols

References and Notes

• 1a Migita T. ShimizuT . Asami Y. Shiobara J. Kato Y. Kosugi M. Bull. Chem. Soc. Jpn.  1980,  53:  1385 
• 1b Kosugi M. Ogata T. Terada M. Sano H. Migita T. Bull. Chem. Soc. Jpn.  1985,  58:  3657 
• 1c Fernández-Rodríguez MA. Shen Q. Hartwig JF. J. Am. Chem. Soc.  2006,  128:  2180 
• 1d Fernández-Rodríguez MA. Shen Q. Hartwig JF. Chem.-Eur. J.  2006,  12:  7782 
• 1e Fernández-Rodríguez MA. Hartwig JF. J. Org. Chem.  2009,  74:  1663 
• 1f Zheng N. McWilliams JC. Fleitz FJ. Armstrong JD. Volante RP. J. Org. Chem.  1998,  63:  9606 
• 1g Itoh T. Mase T. Org. Lett.  2004,  6:  4587 
• 1h Mispelaere-Canivet C. Spindler J.-F. Perrio S. Beslin P. Tetrahedron  2005,  61:  5253 
• 1i Schopfer U. Schlapbach A. Tetrahedron  2001,  57:  3069 
• 1j Jiang Z. She J. Lin X. Adv. Synth. Catal.  2009,  351:  2558 
• 2a Bates CG. Gujadhur RK. Venkataraman D. Org. Lett.  2002,  4:  2803 
• 2b Kwong FY. Buchwald SL. Org. Lett.  2002,  4:  3517 
• 2c Wu Y.-J. He H. Synlett  2003,  1789 
• 2d Bates CG. Saejueng P. Doherty MQ. Venkataraman D. Org. Lett.  2004,  6:  5005 
• 2e Deng W. Zou Y. Wang Y.-F. Liu L. Guo Q.-X. Synlett  2004,  1254 
• 2f Palomo C. Oiarbide M. Lopez R. Gomez-Bengoa E. Tetrahedron Lett.  2000,  41:  1283 
• 2g Savarin C. Srogl J. Liebeskind LS. Org. Lett.  2002,  4:  4309 
• 2h Herradura PS. Pendola KA. Guy RK. Org. Lett.  2000,  2:  2019 
• 2i Chen Y.-J. Chen H.-H. Org. Lett.  2006,  8:  5609 
• 2j Zhu D. Xu L. Wu F. Wan BS. Tetrahedron Lett.  2006,  47:  5781 
• 2k Rout L. Sen TK. Punniyamurthy T. Angew. Chem. Int. Ed.  2007,  46:  5583 
• 2l Ranu BC. Saha A. Jana R. Adv. Synth. Catal.  2007,  349:  2690 
• 3a Pantaleon OB. Ortega SH. Morales DM. Adv. Synth. Catal.  2006,  348:  236 
• 3b Zhang Y. Ngeow KC. Ying JY. Org. Lett.  2007,  9:  3495 
• 4 Wong YC. Jayanth TT. Cheng CH. Org. Lett.  2006,  8:  5613 
• 5 Murthy SN. Madhav B. Reddy VP. Nageswar YVD. Eur. J. Org. Chem.  2009,  5902 
• For recent reviews of iron catalysis, see:
• 6a Bolm C. Legros J. Paih JL. Zani L. Chem. Rev.  2004,  104:  6217 
• 6b Enthaler S. Junge K. Beller M. Angew. Chem. Int. Ed.  2008,  47:  3317 
• 6c Correa A. Mancheno OG. Bolm C. Chem. Soc. Rev.  2008,  37:  1108 
• 6d Sherry BD. Fürstner A. Acc. Chem. Res.  2008,  41:  1500 
• 7a Guo D. Huang H. Xu J. Jiang H. Liu H. Org. Lett.  2008,  10:  4513 
• 7b Correa A. Bolm C. Angew. Chem. Int. Ed.  2007,  46:  886 
• 7c Correa A. Carril M. Bolm C. Angew. Chem. Int. Ed.  2008,  47:  2880 
• 7d Bistri O. Correa A. Bolm C. Angew. Chem. Int. Ed.  2008,  47:  586 
• 8 Wu J.-R. Lin C.-H. Lee C.-F. Chem. Commun.  2009,  4450 
• 9a Reddy VP. Kumar AV. Swapna K. Rao KR. Org. Lett.  2009,  11:  951 
• 9b Reddy VP. Kumar AV. Swapna K. Rao KR. Org. Lett.  2009,  11:  1697 
• 9c Reddy VP. Swapna K. Kumar AV. Rao KR.
  J. Org. Chem.  2009,  74:  3189 
• 9d Kumar AV. Reddy VP. Sridhar R. Srinivas B. Rao KR. Synlett  2009,  739 
• 9e Reddy VP. Swapna K. Kumar AV. Rao KR. Synlett  2009,  2783 
• 9f Reddy VP. Swapna K. Kumar AV. Rao KR. Tetrahedron Lett.  2010,  51:  293 
• 10 Swapna K. Kumar AV. Reddy VP. Rao KR. J. Org. Chem.  2009,  74:  7514 
• 11 Savoia D. Trombini C. Ronchi AU. Pure Appl. Chem.  1985,  57:  1887 ; and the references cited therein
• 14 Hunter DH. Cram DJ. J. Am. Chem. Soc.  1966,  88:  5765 
• 15 Nagai M. Yoda T. Omi S. Kodomari M. J. Catal.  2001,  201:  105 
• 16 Surface Analysis by Auger and X-ray Photoelectron Spectroscopy   Grant JT. Briggs D. IM Publications; Chichester: 2003. 
• 18 Buchwald SL. Bolm C. Angew. Chem. Int. Ed.  2009,  48:  5586 

12

Procedure for the catalyst preparation, characterization can be adopted from the experimental section in the Supporting Information.

13

Percentage weight with respect to iron (not mol%).

17

Experimental section for the spectral discussion.

19

Typical Procedure for C-S Cross-Coupling Fe/Cg (7 wt%, 162 mg) was added to a 25 mL flask, which was previously charged with iodoarene (1.2 mmol), thiol
(1 mmol) and KOH (2.0 equiv). Dry DMSO (1.5 mL) was added while purging the flask with nitrogen. The round-bottom flask was purged once again and back filled with nitrogen and heated in an oil bath at 125 ˚C for a period of 24 h after which the flask was removed from the oil bath and allowed to come to r.t. Fe/Cg was removed by ultracentri-fugation at 8000 rpm. After which the reaction mixture was poured into H₂O (5 mL), and the aqueous layer was extracted with EtOAc (3 × 10 mL).