Toward safer processes for C− C biaryl bond construction: catalytic direct C− H arylation and tin-free radical coupling in the synthesis of pyrazolophenanthridines

S Hernández, I Moreno, R SanMartin…

Index: Hernandez, Susana; Moreno, Isabel; SanMartin, Raul; Gomez, German; Herrero, Maria Teresa; Dominguez, Esther Journal of Organic Chemistry, 2010 , vol. 75, # 2 p. 434 - 441

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Citation Number: 33

Abstract

A series of pyrazolo [1, 5-f] phenanthridine derivatives has been efficiently synthesized by a short, straightforward sequence. A tandem amine-exchange/heterocyclization of enaminones was successfully applied to the regioselective preparation of 1, 5- diarylpyrazole intermediates with structure resemblance to relevant nonsteroidal anti- inflammatory drugs such as celecoxib or tepoxalin. The final key step, cyclization by ...