One-Pot Regioselective Synthesis of 3-Benzylthiazolo[3,2-a]indoles by Sequential Sonogashira Coupling Followed by Triethylamine-Induced Cyclization

Abstract

A number of 2-(prop-2-ynylthio)-1H-indoles have been utilized for the synthesis of 3-benzylthiazolo[3,2-a]indoles by Sonogashira­ acetylide-coupling followed by triethylamine-induced regioselective cyclization in a one-pot operation. The cyclization is dependent on the nature of the substituents on the phenyl ring of the substrates.

Sonogashira coupling - palladium catalyst - base-promoted­ cyclization - aryl iodide - thiazoloindole

References

<A NAME="RZ16311SS-1">1</A>

Present address: Tezpur University, Department of Chemistry, Assam-784 028, India.

<A NAME="RZ16311SS-2A">2a</A> Jin Z. Nat. Prod. Rep.  2003,  20:  584 

<A NAME="RZ16311SS-2B">2b</A> Lewis JR. Nat. Prod. Rep.  1999,  16:  389 

<A NAME="RZ16311SS-3A">3a</A> Kalgutkar AS. Crews BC. Marnett L. J. Biochem.  1996,  35:  9076 

<A NAME="RZ16311SS-3B">3b</A> Hutchinson I. Stevens MFG. Westwell AD. Tetrahedron Lett.  2000,  41:  425 

<A NAME="RZ16311SS-4A">4a</A> Schwander H. In Ullman’s Encyclopedia of Industrial Chemistry   Vol. A11:  VCH; Weinheim: 1988.  p.279 

<A NAME="RZ16311SS-4B">4b</A> Mori A. Sekiguchi A. Masui K. Shimada T. Horie M. Osakada K. Kawamoto M. Ikeda T. J. Am. Chem. Soc.  2003,  125:  1700 

<A NAME="RZ16311SS-4C">4c</A> Dolling K. Zaschke H. Schubert H. J. Prakt. Chem.  1979,  321:  643 

<A NAME="RZ16311SS-5A">5a</A> Heravi MM. Keivanloo A. Rahimizadeh M. Bakavoli M. Ghassemzadeh M. Tetrahedron Lett.  2004,  45:  5747 

<A NAME="RZ16311SS-5B">5b</A> Heravi MM. Keivanloo A. Rahimizadeh M. Bakavoli M. Ghassemzadeh M. Neumüller B. Tetrahedron Lett.  2005,  46:  1607 

For a recent review of indole-containing natural products, see:

<A NAME="RZ16311SS-6A">6a</A> Faulkner DJ. Nat. Prod. Rep.  1999,  16:  155 

<A NAME="RZ16311SS-6B">6b</A> Lounasmaa M. Tolvanen A. Nat. Prod. Rep.  2000,  17:  175 

<A NAME="RZ16311SS-7">7</A> Nakashima Y. Kawashima Y. Amanuma F. Sota K. Tanaka A. Kameyama T. Chem. Pharm. Bull.  1984,  32:  4271 

<A NAME="RZ16311SS-8">8</A> Kobayashi G. Furukawa S. Matsuda Y. Natsuki R. Yakugaku Zasshi  1969,  89:  58 ; Chem. Abstr. 1969, 70, 96665

<A NAME="RZ16311SS-9">9</A> Gaster LM, and Wyman PA. inventors; US Patent  5852014. 

<A NAME="RZ16311SS-10A">10a</A> Majumdar KC. Alam S. Org. Lett.  2006,  18:  4059 

<A NAME="RZ16311SS-10B">10b</A> Majumdar KC. Debnath P. Alam S. Islam R. J. Sulfur Chem.  2008,  29:  467 

<A NAME="RZ16311SS-10C">10c</A> Majumdar KC. Debnath P. Alam S. Maji PK. Tetrahedron Lett.  2007,  48:  7031 

<A NAME="RZ16311SS-10D">10d</A> Majumdar KC. Alam S. J. Chem. Res., Synop.  2006,  281 

<A NAME="RZ16311SS-10E">10e</A> Majumdar KC. Alam S. J. Chem. Res., Synop.  2006,  289 

<A NAME="RZ16311SS-11">11</A> Sonogashira K. Tohda Y. Hagihara N. Tetrahedron Lett.  1975,  16:  4467 

<A NAME="RZ16311SS-12A">12a</A> Xu L. Lewis IR. Davidsen SK. Summers JB. Tetrahedron Lett.  1998,  39:  5159 

<A NAME="RZ16311SS-12B">12b</A> Roesch KR. Larock RC. Org. Lett.  1999,  4:  553 

<A NAME="RZ16311SS-12C">12c</A> Nan Y. Miao H. Yang Z. Org. Lett.  2000,  2:  297 

<A NAME="RZ16311SS-12D">12d</A> Nevado C. Echavarren AM. Synthesis  2005,  167 

<A NAME="RZ16311SS-12E">12e</A> Larock RC. Yum EK. J. Am. Chem. Soc.  1991,  113:  6689 

<A NAME="RZ16311SS-12F">12f</A> Larock RC. Yum EK. Refvik MD. J. Org. Chem.  1998,  63:  7652 

<A NAME="RZ16311SS-13A">13a</A> Rodriguez AL. Koradin C. Dohle W. Knochel P. Angew. Chem. Int. Ed.  2000,  39:  2488 

<A NAME="RZ16311SS-13B">13b</A> Henkelmann J, and Arndt J. inventors; Japanese Patent JP  2001233855.  ; Chem. Abstr. 2001, 135, 195572

<A NAME="RZ16311SS-13C">13c</A> Koradin C. Dohle W. Rodriguez AL. Schmid B. Knochel P. Tetrahedron  2003,  59:  1571 

<A NAME="RZ16311SS-13D">13d</A> Harcken C. Ward Y. Thomson D. Riether D. Synlett  2005,  3121 

<A NAME="RZ16311SS-14">14</A> Dawei Y. Larock RC. Org. Lett.  2004,  6:  1037 

<A NAME="RZ16311SS-15A">15a</A> Majumdar KC. Mondal S. Tetrahedron Lett.  2008,  49:  2418 

<A NAME="RZ16311SS-15B">15b</A> Majumdar KC. Mondal S. Tetrahedron Lett.  2007,  48:  6951 

<A NAME="RZ16311SS-16A">16a</A> Majumdar KC. Samanta S. Chattopadhyay B. Tetrahedron Lett.  2008,  49:  7213 

<A NAME="RZ16311SS-16B">16b</A> Majumdar KC. Chattopadhyay B. Samanta S. Synthesis  2009,  311 

<A NAME="RZ16311SS-17">17</A> Takada S. Makisumi Y. Chem. Pharm. Bull.  1984,  32:  872 

<A NAME="RZ16311SS-18A">18a</A> Conreaux D. Belot S. Desbordes P. Monteiro N. Balme G. J. Org. Chem.  2008,  73:  8619 

<A NAME="RZ16311SS-18B">18b</A> Yamamoto Y. G ridnev ID. Patil NT. Jin T. Chem. Commun.  2009,  5075 

<A NAME="RZ16311SS-18C">18c</A> Mphahlele MJ. Molecules  2009,  14:  4814