202131-51-9

Upstream product

• 636-28-2 1,2,4,5-tetrabromobenzene 
• 71-43-2 benzene 

Downstream Products

• 1153689-15-6 1,2,4,5-tetrabromo-3,6-bis[3-(2,3,4,5,6-pentabromophenyloxy)prop-1-yn-1-yl]benzene 
• 1153689-18-9 1,2,4,5-tetrabromo-3,6-bis[3-(2,3,4,5,6-pentabromobenzyloxy)prop-1-yn-1-yl]benzene 
• 1153689-10-1 3-[4-(3-acetoxyprop-1-yn-1-yl)-2,3,5,6-tetrabromophenyl]prop-2-yn-1-yl acetate 
• 960157-29-3 1,2,4,5-tetrabromo-3,6-bis(phenylethynyl)benzene 
• 921755-50-2 9,11,20,22-tetraphenyl-10,21-di-(p-tolyl)tetrabenzo[a,c,l,n]pentacene 9,22:11,20-diepoxide 
• 773149-88-5 9,10,11,20,21,22-hexaphenyltetrabenzo[a,c,l,n]pentacene 9,22:11,20-diepoxide 

Relevant academic research and scientific papers

A pentacene with a 144° twist

9,10,11,20,21,22-Hexaphenyltetrabenzo[a,c,l,n]pentacene (1) was prepared by the reaction of 1,3-diphenylphenanthro[9,10-c]furan with the bisaryne equivalent generated from 1,2,4,5-tetrabromo-3,6-diphenylbenzene in the presence of n-butyllithium, followed by deoxygenation of the double adduct with low-valent titanium. The X-ray structure of 1 shows it to be the most highly twisted polycyclic aromatic hydrocarbon known, with an end-to-end twist of 143.6°. Compound 1 was resolved by chromatography on a chiral support, and the pure enantiomers have specific rotations in excess of 7000°, but the molecule racemizes slowly at 25 °C (t1/2 = 9.3 h, ΔG≠rac = 23.8 kcal/mol). Copyright

Evidence for fully conjugated double-stranded cycles

A chain of circumstantial evidence for the existence of the first fully conjugated, double-stranded cycles is presented. The products have the structure of the belt-region of fullerene C84 (D2) and carry either four hexyl chains or four phenyl groups. The unsubstituted parent cycle is also presented. The chain of evidence is mainly based on mass spectrometric analysis and trapping reactions, the latter being supported by quantum mechanical calculations. It is also of importance that the phenyl-substituted and unsubstituted products cannot undergo a [1,5] hydrogen shift, the only reasonable side-reaction that recently could not be excluded for the alkyl-substituted analogue. It is concluded that the fully aromatic targets truly exist in the gas phase. Whether they can be generated in solution under the applied conditions cannot yet be firmly decided; theoretical evidence speaks against.

Cross coupling of polybromoiodobenzenes with some terminal alkynes

Sonogashira reactions of pentabromoiodobenzene and tetrabromo-1,4- diiodobenzene with various terminal alkynes at 20°C in benzene resulted in selective replacement of the iodine atoms with formation of the corresponding alk-1-yn-1-yl-substituted polybromobenzenes.

Synthesis, structure, and resolution of exceptionally twisted pentacenes

9,10,11,20,21,22-hexaphenyltetrabenzo[a,c,l,n]pentacene (2) and a dimethyl derivative (2m) were prepared by the reaction of 1,3-diphenylphenanthro[9,10-c] furan with bisaryne equivalents generated from 1,2,4,5-tetrabromo-3,6- diarylbenzenes in the presenc