167258-91-5

Upstream product

• 95045-18-4 dimethyl 5,6,8,10-tetramethylheptalene-1,2-dicarboxylate 
• 100-52-7 benzaldehyde 
• 762-42-5 dimethyl acetylenedicarboxylate 
• 166389-97-5 4,6,8-trimethyl-1-<(E)-2-phenylethenyl>azulene 

Relevant academic research and scientific papers

A spectroscopic investigation of donor-acceptor-substituted heptalenes

It is shown that the heptalene-4,5-dicarboxylates 5 react with their Me group at C(1) with N,N-dimethylformamide dimethyl acetal or other acetals of this type in N,N-dimethylformamide (DMF) to give the corresponding 1-[(E)-2-(N,N-dialkylamino)ethenyl]-sub

DOUBLE-BOND SHIFTS OF SUBSTITUTED (4N)-ANNULENES FOR INFORMATION STORAGE AND DATA PROCESSING

The present application describes a method for information storage and data processing comprising the steps of thermo inducing or photo inducing double-bond shifts (DBS) in substituted (4n)-annulenes thus generating transitions between two different conjugation states with at least one substituent. The two different conjugation states are the conjugation on-state and conjugation off-state of the annulene core pi-electrons with the substituent pi-electrons. The present invention is furthermore related to novel substituted (4n)-heptalenes being optically and/or thermally switchable, based on thermal or photochemical double-bond shifts (DBS) as well as methods for their preparation. The (4n)-heptalenes can be used for information storage and data processing devices.

New syntheses of di-π-substituted heptalenes

To study the effect of double-bond shifts (DBS) in different type of heptalenes linked to extended π-systems, several di-π-substituted heptalenes were synthesized. 6-[(E)-Styryl]heptalene-dicarboxylate 4 was smoothly converted to 1-(chloromethyl)heptalene

Thermal and Ru-catalyzed Reactions of Styryl-Substituted Azulenes with Dimethyl Acetylenedicarboxylate

The thermal reaction of 1-azulenes with dimethyl acetylenedicarboxylate (ADM) in decalin at 190-200 deg does not lead to the formation of the corresponding heptalene dicarboxylates (Scheme 2).Main products are the corresponding azulene-1,2-dicarboxylates (see 4 and 9), accompanied by the benzanellated azulenes trans-10a and trans-11, respectively.The latter compounds are formed by a Diels-Alder reaction of the starting azulenes and ADM, followed by an ene reaction with ADM (cf.Scheme 3).The -catalized reaction of 4,6,8-trimethyl-1-azulenes (R=H, MeO, Cl; Scheme 4) with ADM in MeCN at 110 deg yields again the azulene-1,2-dicarboxylates as main products.However, in this case, the corresponding heptalene-1,2-dicarboxylates are also formed in small amounts (3-5percent; Scheme 4).The benzanellated azulenes trans-10a and trans-10b are also found in small amounts (2-3percent) in the reaction mixture.ADM Addition products at C(3) of the azulene ring as well as at C(2) of the styryl moiety are also observed in minor amounts (1-3percent).Similar results are obtained in the -catalyzed reaction of 3-guaiazulene; ((E)-8; Scheme 5) with ADM in MeCN.However, in this case, no heptalene formation is observed, and the amount of the ADM-addition products at C(2) of the styryl group is remarkably increased (29percent).That the substituent pattern at the seven-membered ring of (E)-8 is not responsible for the failure of heptalene formation is demonstrated by the Ru-catalyzed reaction of 7-isopropyl-4-methyl-1azulene ((E)-23; Scheme 11) with ADM in MeCN, yielding the corresponding heptalene-1,2-dicarboxylate (E)-26 (10percent).Again, the main product is the corresponding azulene-1,2-dicarboxylate 25 (20percent).Reaction of 4,6,8-trimethyl-2-azulene ((E)-27); Scheme 12) and ADM yields the heptalene-dicarboxylates (E)-30A/B, purely thermally in decalin (28percent) as well as Ru-catalyzed in MeCN (40percent).Whereas only small amounts of the azulene-1,2-dicarboxylate 8 (1 and 5percent, respectively) are formed, the corresponding benzanellated azulene trans-29 is found to be the second main product under both reaction conditions.The thermal reaction yields also the benzanellated azulene 28 which is not found in the catalyzed variant of the reaction.Heptalene-1,2-dicarboxylates are also formed from 4-azulenes (e.g. (E)-33 and (E)-34; Scheme 14) and ADM at 180-190 deg in decalin and at 110 deg in MeCN by catalysis.The yields (30percent) are much better in the catalized reaction.The formation of by-products (e.g. 39-41; Scheme 14) in small amounts (0.5-5percent) in the Ru-catalized reactions allows to understand better the reactivity of zwitterions (e.g. 42 and their tricyclic follow up products (e.g. 43) built from azulenes and ADM (cf.Scheme 15).