SmI2-Mediated Carbon−Carbon Bond Fragmentation in α-Aminomethyl Malonates

I2/Cu-mediated self-sorting domino reaction of aryl β-ketoesters into symmetrical 2-carboalkoxy-1,4-enediones: application to synthesis of pyrazine, β-carboline and quinoxalines

A self-sorting domino reaction of aryl β-ketoesters into symmetrical 1,4-enediones is reported by an I₂/Cu system.

Overturning established chemoselectivities: selective reduction of arenes over malonates and cyanoacetates by photoactivated organic electron donors

The prevalence of metal-based reducing reagents, including metals, metal complexes, and metal salts, has produced an empirical order of reactivity that governs our approach to chemical synthesis. However, this reactivity may be influenced by stabilization of transition states, intermediates, and products through substrate-metal bonding. This article reports that in the absence of such stabilizing interactions, established chemoselectivities can be overthrown. Thus, photoactivation of the recently developed neutral organic superelectron donor 5 selectively reduces alkyl-substituted benzene rings in the presence of activated esters and nitriles, in direct contrast to metal-based reductions, opening a new perspective on reactivity. The altered outcomes arising from the organic electron donors are attributed to selective interactions between the neutral organic donors and the arene rings of the substrates.

Copper catalyzed arylation/C-C bond activation: an approach toward alpha-aryl ketones

An efficient arylation/C-C activation process was discovered. Beta-diketones with aryl halides (aryl iodides and aryl bromides) could undergo reaction smoothly in the presence of Cu(I) or Cu(II) salts in DMSO using K(3)PO(4) x 3 H(2)O without ligands. The role of H(2)O was unprecedented, which assisted the C-C activation. Various alpha-aryl ketones could be efficiently synthesized by this novel method. In situ monitoring of the formation of KOAc and experimentation relating to "a classic diagnostic technique for the participation of radical anion intermediates" revealed the preliminary mechanistic information for the reaction. This method is simple, general, and practical which complemented the classic method for the rapid construction of C-C bonds to a carbonyl moiety.