Synthesis and characterization of S,N-heteroacenes by Bischler-Napieralski reaction

A Potential Iterative Approach to 1,4‐Dihydro‐N‐Heteroacene Arrays

“…Phenazinediamine and its analogues have been used as building blocks, [20] three-dimensional pyrene-fused N-heteroa-cenes were made by an iterative approach, [21] layered thiadiazoloquinoxaline-containing long pyrene-fused N-heteroacenes, [22] azaacenodibenzosuberones, [23] N-heteroacenes extended through a four-membered ring, [24] N-phenylated Nheteroacenes, [25] and novel types of sulfur-nitrogen-containing N-heteroacenes containing a high proportion of heteroatoms. [26] In the preliminary communication here, we report a synthesis and crystallographic structure for a non-planar mono-Nsubstituted dihydrophenazine and explain its significance.…”

“…Large N‐heteroacenes have been made by various methods. Phenazinediamine and its analogues have been used as building blocks, [20] three‐dimensional pyrene‐fused N‐heteroacenes were made by an iterative approach, [21] layered thiadiazoloquinoxaline‐containing long pyrene‐fused N‐heteroacenes, [22] azaacenodibenzosuberones, [23] N‐heteroacenes extended through a four‐membered ring, [24] N ‐phenylated N‐heteroacenes, [25] and novel types of sulfur‐nitrogen‐containing N‐heteroacenes containing a high proportion of heteroatoms [26] …”

Thiophene-Based Trimers and Their Bioapplications: An Overview

“…Functional pendant groups carrying an amine or a carboxylic acid were attached respectively to trimer carboxylic acid [ 303 , 304 , 377 , 378 , 379 , 380 , 381 ] or amine ( Scheme 20 , I and II) [ 207 , 208 , 209 , 382 ]. The amide formation occurs on the side group of the central thiophene either before [ 377 , 378 , 379 , 380 ] or after [ 207 , 381 , 382 ] the formation of the trimer and it is typically achieved by carboxylic acid activation by acyl chloride [ 207 , 208 , 209 , 378 ] or a carbodiimide coupling agent [ 377 , 379 , 380 , 381 ], followed by amine nucleophilic substitution. Instead, the reaction between a trimer diester and hydrazine leads to the formation of a pyridazinedione pendant group on the central unit ( Scheme 20 , III) [ 366 , 367 ].…”

Bischler‐Napieralski Cyclization: A Versatile Reaction towards Functional Aza‐PAHs and Their Conjugated Polymers†

“…What's more, if different aromatic rings were adopted, such as phenyl, thiophenyl, and benzothiadiazole, a wide variety of aza‐heteroacenes and S,N‐heteroacenes could be obtained (Figure 2). [ 104 ] Systematic studies revealed that despite the high tolerability of Bischler‐Napieralski cyclization with different types of aromatic moieties, the reactivity was mainly affected by the electronic effects of the aromatic rings. For instance, cyclization of thiophene‐containing precursors generally resulted in high yields ( e.g ., yield: 18a > 19a , 18b > 19b ), since the electron‐rich thiophene moiety is more active in intramolecular electrophilic substitution than the phenyl group.…”

“…Reproduced with permission. [ 104 ] Copyright © 2016, Chinese Chemical Society, Institute of Chemistry, Chinese Academy of Sciences and Springer‐Verlag Berlin Heidelberg).…”