A Biaryl-Cyclohexenone Photoelectrocyclization/Dearomatization Sequence to Substituted Terpenes.

Described here is the development of sequential cross-coupling, photoelectrocyclizations, and reductive dearomatizations of biaryl cyclohexenones as a means of synthesizing terpene skeletons. This methodology promises to provide insight that will enable us and others to use this approach to generate a variety of biologically active small molecules, including members of the abietane and morphinan skeletons.

Reactivity of vinyl phosphonate containing diazoesters: formation, reactivity, and utility.

Treatment of diazo vinyl phosphonate with alcohols, amines, and thiols in the presence of Rh(II) results in the chemo- and stereoselective generation of enol ethers, enamines and vinyl sulfides via an X-H insertion process. The utility of the products from these reactions was demonstrated through their conversion into quaternary substituted heterocycles including furans and oxetanes as highlighted by the generation of a bicyclic phosphonate analogue of neodysiherbaine.

Exceptionally Long (≥2.9 Å) C-C Bonds between [TCNE] Ions: Two-Electron, Four-Center π*-π* C-C Bonding in π-[TCNE].

Attractive interaction with the cation overcomes the electrostatic repulsion between two tetracyanoethylene radical anions, [TCNE] , and leads to the formation of a diamagnetic dimer [TCNE] , for example, in [K(glyme)] [TCNE] . The bonding is described as two-electron, four-center bonding arising from π*-π* overlap. Crystallographic as well as spectroscopic (IR and UV/Vis) features of this bonding are observed.

Comparison of the X-ray crystallography of undecafluorocyclohexane, C(6)HF(11), with that of dodecafluorocyclohexane, C(6)F(12).

A comparison of undecafluorocyclohexane and dodecafluorocyclohexane shows that both exist at 23 degrees in face-centred cubic cells with edges a(0) = 10.00 +/- 0.02 A for C(6)HF(11) and a(0) = 10.