A silver-catalyzed Büchner reaction

Transition metals in organic synthesis: Highlights for the year 2005

“…(113)) [752]. Silver catalyzed the reaction of ethyldiazoethanoate with aromatic compounds forming cycloheptatrienes [753]. A related copper-catalyzed ring-expansion of benzopyrylium triflates was reported affording 2,3-benzooxepins [754].…”

Silver Carbenoids

“…43 The Tp ð3;5-CF 3 Þ 2 Ag complex 22 and the related silver complex 33 were examined in C--H insertion reactions with several acyclic alkanes. 17,20,42 The chemical yields were excellent, and interestingly, both complexes exhibited relatively high proportions of C--H insertion at the primary carbon (Table 8.7). Perez and coworkers speculated that this increase selectivity for insertion at primary sites was due to increased electrophilic character at the metal center rather than steric factors.…”

“…Instead, a rather complex mixture of products was obtained containing the expected cyclopropane 24 (Scheme 8.4), the ring expanded product 25, the solvent insertion product 26 and other products (possibly 27). 17 This is in contrast to the corresponding copper complex, which smoothly cyclopropanoates a variety of olefins, including styrene. 19 Ultimately it was found that by conducting the reaction with benzene in CH 2 Cl 2 or in neat benzene, the ring expansion product 30a, via the norcaradiene 29a (B€ uchner reaction), was obtained in good yield (Scheme 8.5).…”

“…19 Ultimately it was found that by conducting the reaction with benzene in CH 2 Cl 2 or in neat benzene, the ring expansion product 30a, via the norcaradiene 29a (B€ uchner reaction), was obtained in good yield (Scheme 8.5). 17 scope revealed that other aromatic derivatives, 28b-f, participated in the rearrangement, but generally the yields of the ring-expanded product 30b-f were lower than with benzene (Table 8.1). In some cases (30b and 30f), competitive benzylic C--H insertion was observed, providing 31 and 32, respectively ( Fig.…”

“…More recently, both our group and Perezs group have demonstrated that Ag complexes 22 and 33 containing scorpionate ligands are effective for C--H insertion with diazoacetates (Scheme 8.16) 17,20,42. Complex 22 efficiently effects insertion of…”