The Chemistry of Vicinal Polycarbonyl Compounds

A Cyclic Vicinal Bis(tetraketone) and Structural Investigations of Formoins

“…[3,4] Common to all of them is their high electrophilicity, demonstrated by the formation of hydrates in the presence of water, and their electron acceptor properties, as attested to by their low reduction potentials. [4] Cyclic vicinal tetraketones have been available since 1986, [5Ϫ8] by oxidation variously of cyclic formoins (in this paper we use the trivial name ''formoin'' because it comprises not only the cyclic form dihydroxyfurane (D in Scheme 4) but also the diketo-enediol form (B in Scheme 4). [5] of a butane-2,3-dione fragment 1, [6,7] or of a 1,4-diprotected 1,4-dihydroxy-2-butyne moiety 4.…”

Controlling the Bonding and Band Gaps of Solid Carbon Monoxide with Pressure

“…The P2 1 =m phase was not seen in a recent experiment [16], implying that a different synthesis path might be needed, for instance, quenching from the high pressure polymeric phases at low temperature. Alternatively, short polycarbonyl chains [up to R-ðCOÞ 5 -R] have already been synthesized by organic chemists [25], and it is not implausible to imagine that longer chains could be made.…”

Carbon Dioxide Insertion into Uranium‐Activated Dicarbonyl Complexes

“…[16] To extend the process depicted in Scheme 1 to generate extended carbon chains, the reduction and chain extension of tricarbonyl (and greater) compounds must be achieved. In efforts to test the viability of such processes, 1 was treated with tBuCOCOCOtBu, [17] resulting in the formation of a dinuclear complex 8 b, in which the triketone has undergone two-electron reduction, as judged by x-ray crystallography ( Figure 2). The C À C bonds of the tricarbonyl moiety of this complex measure 1.45 and 1.39 , indicating that the two C À C bonds are inequivalent and that one of the two has almost complete double-bond character.…”