60004-33-3

Upstream product

• 1195-93-3 2,2,6,6-tetramethylcyclohexanone 
• 128923-70-6 1,4-bis(1-hydroxy-2,2,6,6-tetramethylcyclohexyl)butadiyne 
• 104850-85-3 1-ethynyl-2,2,6,6-tetramethylcyclohexanol 
• 128923-72-8 2,3-dibromo-1,4-bis(2,2,6,6-tetramethylcyclohexylidene)-1,3-butadiene 

Downstream Products

• 128923-75-1 1,2,3,4-tetrakis[(2,2,6,6-tetramethylcyclohexylidene)methylene]cyclobutane 
• 128923-74-0 2,3,4,5-tetrakis[(2,2,6,6-tetramethylcyclohexylidene)methylene]cyclopentanone 

Relevant academic research and scientific papers

Nickel-catalyzed dimerization of [5]cumulenes (Hexapentaenes)

Tetraaryl[5]cumulenes react with low-valent nickel complexes at the second double bond to produce novel [4]radialene derivatives that are head-to-head dimers of [5]cumulenes. The head-to-head dimers are also synthesized by a stepwise route. On the other hand, the nickel-catalyzed dimerization of [5]cumulenes with bulky substituents produces other types of extended [4]radialenes and [5]radialenones depending on the bulkiness of the terminal alkyl substituents. Thus, tetrakis-t-butyl[5]cumulene and 1,4-bis(2,2,6,6- tetramethylcyclohexylidene)[3]cumulene react at the central double bond to give the corresponding [4]radialene and [5]radialenone, whereas 1,4-bis(2,2,5,5- tetramethylcyclopentylidene)[3]cumulene and its benzo-annelated derivative react at the second double bond in a head-to-tail manner to afford the corresponding extended [4]radialenes. Tetrakis-t-butyl[5]radialenone was converted into [5]radialene by using a methylation-dehydration procedure. The extended [4]- and [5]radialenes and [5]radialenones have been fully characterized by spectroscopic analyses, X-ray crystallography, and/or independent chemical synthesis. The properties of these novel exocyclic π-electron systems have been investigated in detail. The aryl-substituted [4]radialenes exhibit facile bond rotation with low energy barriers. The [5]radialene and [5]radialenone form the corresponding cations easily by the addition of an acidic proton. The selectivity of the nickel-catalyzed dimerization of [5]cumulenes is discussed on the basis of theoretical calculations.

SYNTHESIS AND REACTION OF NOVEL SULFUR CONTAINING HETEROCYCLIC SYSTEMS

The strained alkylidene episulfides were synthesized by carbene and alkylidene carbene additions to thiocarbonyl compounds.Thermal, photochemical, and acid catalyzed reactions have been extensively investigated, and the transition metal-promoted reaction