383191-41-1

Upstream product

• 120651-33-4 ((2‐ethynylphenyl)ethynyl)trimethylsilane 
• 6630-33-7 ortho-bromobenzaldehyde 
• 1404452-67-0 ((2‐(2,2‐dibromovinyl)phenyl)ethynyl)trimethylsilane 
• 77123-58-1 2-[2-(trimethylsilyl)ethynyl]benzaldehyde 
• 383191-52-4 1-(2-Bromo-phenylethynyl)-3,5-dimethyl-benzene 
• 766-46-1 2-bromo-1-ethynylbenzene 
• 22445-41-6 3,5-dimethylphenyl iodide 
• 383191-54-6 ({2-[(3,5-dimethylphenyl)ethynyl]phenyl}ethynyl)(trimethyl)silane 

Downstream Products

• 383191-42-2 3-(4-{1-tert-butyl-3-[2-(3,5-dimethyl-phenylethynyl)-phenyl]-1-hydroxy-prop-2-ynyl}-phenyl)-1-[2-(3,5-dimethyl-phenylethynyl)-phenyl]-4,4-dimethyl-pent-1-yn-3-ol 

Relevant academic research and scientific papers

CO extrusion in homogeneous gold catalysis: Reactivity of gold acyl species generated through water addition to gold vinylidenes

Herein, we describe a new gold-catalyzed decarbonylative indene synthesis. Synergistic σ,π-activation of diyne substrates leads to gold vinylidene intermediates, which upon addition of water are transformed into gold acyl species, a type of organogold compound hitherto only scarcely reported. The latter are shown to undergo extrusion of CO, an elementary step completely unknown for homogeneous gold catalysis. By tuning the electronic and steric properties of the starting diyne systems, this new reactivity could be exploited for the synthesis of indene derivatives in high yields.

Novel synthesis of 4,5-diarylphenanthrenes via C2-C6 cyclization of benzannulated enyne-allenes

A new synthetic pathway to the 4,5-diarylphenanthrenes 8 having a helical twist in their structures was developed. The synthetic sequence involves condensation of the diketone 5 with 2 equiv of the lithium acetylides derived from the diacetylenes 4 followed by protonation to produce the propargylic alcohols 6. Reduction of 6 with triethylsilane in the presence of trifluoroacetic acid furnished the tetraacetylenic hydrocarbons 7 in nearly quantitative yields. Treatment of 7 with potassium tertbutoxide under refluxing toluene at 110 °C for up to 10 h then furnished the 4,5-diarylphenanthrenes 8. Apparently, the transformation from 7 to 8 involves initial prototropic isomerizations to form the benzannulated enyne-allenes 9. Two subsequent formal intramolecular Diels-Alder reactions via the biradicals 10 and 12 derived from the C2-C6 cyclizations then led to 13, which in turn underwent tautomerizations to give 8. The structure of 8a was established by the X-ray structure analysis, showing that the two phenyl substituents are bent away from each other and the central aromatic system is severely distorted with a helical twist. The existence of a helical twist in 8 imposed by the aryl groups at the 4- and 5-positions was also revealed with a set of AB 1H NMR signals for the diastereotopic methylene hydrogens on the five-membered rings.