Copper(I) Catalyzed Decarboxylative Synthesis of Diareno[a,e]cyclooctatetraenes

Abstract

Diareno[ a , e ]cyclooctatetraenes find widespread applications as building blocks, ligands, and responsive cores in topologically switchable materials. However, current synthetic methods to these structures suffer from low yields or operational disadvantages. Here, we describe a practical three-step approach to diareno[ a , e ]cyclooctatetraenes using an efficient copper(I) catalyzed double decarboxylation as the key step. The sequence relies on cheap and abundant reagents, is readily performed on scale, and is amenable also to unsymmetrical derivatives that expand the utility of this intriguing class of structures.

The poisonous truth about the mercury drop test: the effect of elemental mercury on Pd(0) and Pd(II)ArX intermediates

“…29 However, due to challenging reaction conditions such as the necessity to be carried out at low temperatures for CS2 (and hence extended reaction times), and in the case of the DCT synthetic technique, their poor yields, these tests are not widely utilized. 30 The mercury drop test is the most widely used poisoning test for distinguishing between homogeneous and heterogeneous catalysis. [31][32][33][34] This test is based on the simple assumption that elemental mercury, Hg 0 , will amalgamate with metal heterogeneous catalysts, M 0 , considerably reducing or eliminating their catalytic activity, while homogeneous metals of higher oxidation states bearing protective ligands, LnMX, will be left unaffected (Scheme 1).…”