Synfacts 2006(5): 0427-0427  
DOI: 10.1055/s-2006-934365
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

Transformations of 3-Zinciobenzofurans and 3-Zincioindoles

Contributor(s): Victor Snieckus, Oleg M. Demchuk
M. Nakamura*, L. Ilies, S. Otsubo, E. Nakamura*
The University of Tokyo; Nakamura Functional Carbon Cluster Project ERATO, Japan Science; Technology Agency Hongo, Tokyo, Japan
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Publikationsverlauf

Publikationsdatum:
21. April 2006 (online)

Significance

Starting from a simple, Sonoga­shira-derived 2-ynyl phenol or 2-ynyl aniline A, a potentially general approach to functionalized conjugated benzoheteroles (benzofurans and indoles) C via 3-zincio intermediates B is presented. Thus, Negishi cross-coupling of species B with various halides affords products C in excellent yields. Protonation, deuteration, and reaction with iodobenzene lead to the formation of 3-H-, 3-D-, and 3-phenyl-substituted heteroles C (n = 1). The low reactivity of the zinc phenoxide intermediates in the absence of TMEDA is rationalized by their propensity to form coordinatively saturated oxygen-bridged aggregates, in contrast to the corresponding zinc anilides.