Carbanions, copper® acetate

Ames and Ribeira (75JCS(Pl)1390) described a method for the preparation of thieno[2,3-c]pyridin-7-ones (Scheme 68). The sodium salt of 3-bromothiophene-2-carboxylic acid reacts with carbanions in the presence of copper or copper(II) acetate to give condensation products (274) by displacement of bromide ion, often with simultaneous deacetylation. Cyclization of (274) provides a convenient route to thieno[2,3-c]pyridin-7-ones. Thieno[2,3-c]pyridin-4-ones and thieno[3,2-c]pyridin-7-ones have been prepared by Friedel-Crafts cyclization of AT-(2-thenyl)- and A-(3-thenyl)-glycine derivatives (81H(l6)127l). 

Oxidation of a-sulfonyl carbanions with copper(II) trifluoromethanesulfonate gives dimers of the original sulfone, while with copper(II) acetate vinylic sulfones were obtained (Scheme 74). ... 

The method of Ames and Ribeiro,64 already referred to briefly, would appear to offer an attractive route to a wide variety of hitherto inaccessible thienol 3,4-c]pyridines. The sodium salt of 4-bromothiophene-3-carboxylic acid reacts with carbanions, in the presence of copper or copper(II) acetate, to give condensation products (42) by displacement of bromide ion. With certain carbanions (e.g., those derived from PhCOCH2CN, MeCOCHjC02Et, PhCOCHjCOMe) deacylation (loss of PhCO, MeCO and MeCO, respectively) occurred simultaneously ... 

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