Stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reactionbetween hydantoins or thiohydantoins and dialkyl acetylenedicarboxylates in the presence oftriphenylphosphine. These phosphoranes undergo smooth intramolecular Wittig reaction followedby an electrocyclic ring opening to produce dialkyl (E)-2-(2,5-dihydro-5,5-diaryl-2-thioxo-1H-imidazol-4-yl)fum...

Ionic liquids such as 1,3-dialkylimidazolium salts make excellent catalysts and solvents for synthesis of dialkyl 2-(dialkoxyphosphoryl)-3-(1-oxo-1-H-phthalazin-2-yl)succinates from 2H-phthalazin-1-one, dialkyl acetylenedicarboxylates, and trialkyl phosphites. Under similar conditions, triphenyl phosphite led to dialkyl 2-(diphenoxyphosphoryl)-3-(1-oxo-1-H-phthalazin-2-yl)succinates. The ionic ...

A catalytic atroposelective cycloaddition reaction between thioureas and ynals is developed. This features the first NHC-catalyzed addition of to acetylenic acylazolium intermediates eventually set up C?N axial chirality with excellent optical purities. The obtained axially chiral thiazine derivative products bear multiple functional groups are feasible for further transformations.

We here identify by ab initio calculations a new type of three-dimensional (3D) carbon allotropes that consist of phenyl rings connected by linear acetylenic chains in sp+sp(2) bonding networks. These structures are constructed by inserting acetylenic or diacetylenic bonds into an all sp(2)-hybridized rhombohedral polybenzene lattice, and the resulting 3D phenylacetylene and phenyldiacetylene n...