Synfacts 2006(6): 0548-0548  
DOI: 10.1055/s-2006-934499
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

Palladium(II)-Catalyzed Cyclization of 3-(3′-Alkenyl)indoles to Carbazoles

Contributor(s): Victor Snieckus, Wei Gan
A. Kong, X. Han, X. Lu*
Shanghai Institute of Organic Chemistry, P. R. Of China
Further Information

Publication History

Publication Date:
19 May 2006 (online)

Significance

A mild, one-pot Pd-catalyzed cyclization of 3-(3′-alkenyl)indoles to carbazole derivatives in yields up to 88% is described. The presence of N- and vinyl substituents (R1, R2 = Me) plays a crucial role in the desired endo-mode of cyclization; otherwise, exo-cyclization occurs leading to byproducts. A terminal olefin is obligatory for the endo-cyclization reaction. Benzoquinone was shown to be the best oxidant among several tested.