The preparation of substituted bithiophenyl aldehydes via the ring opening of dithieno[2,3-b:3′,2′-d]thiophene in the presence of n-BuLi

Ring-opening reaction of 2,5-dioctyldithieno[2,3-b:3',2'-d]thiophene in the presence of aryllithium reagents

“…Compared to the compound 2d (Table 1, entry 4) bearing EWG groups, the compounds 2b , 2c and 2e (Table 1, entries 2, 3 and 5), all of which have EDG groups, generated higher yields of products, namely 73% ( 3b ), 74% ( 3c ) and 83% ( 3e ), respectively. In the case of 2b , not only was 3b obtained, but also a byproduct with similar polarity, 2'-butylsulfanyl-5,5'-dioctyl-[3,3'-bithiophene]-2-carbaldehyde [5], was generated when the metal–halogen exchange temperature was set to −78 °C. If the reaction temperature of the metal–halogen exchange was set to −78 °C first, and then warmed up to −30 °C for 3 h, only 3b could be generated in 70% yield (Table 1, entry 3).…”

“…In our previous work, we reported the synthesis of a series of symmetric substituted dithieno[2,3- b :3',2'- d ]thiophenes and their ring-opening reactions in the presence of n -BuLi. The 3,3'-bithiophene-2-carbaldehydes were generated after quenching with an electrophile, i.e., dry DMF (Scheme 1) [5]. …”

Synthesis, reactions and biological evaluation of some novel thienothiophene derivatives

“…Furthermore, attention has been increasingly paid in recent years to the synthesis of bis-heterocyclic for their numerous applications as electrical materials [17], chelating agents, and metal ligands [18]. They also exhibit various biological activities including antibacterial, fungicidal, tuberculostatic, antitumor and as antimicrobial [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] and plant growth regulative properties [39,40]. Moreover, compounds including bis-heterocyclic moieties were encountered in many bioactive natural product and recent reports showed that among libraries of derivatized heterocycles, the most active library compounds had a bis-heterocyclic structure [41][42][43][44][45][46][47][48][49].…”

2‐Bromo‐1‐(1H‐pyrazol‐4‐yl)ethanone: Versatile Precursor for Novel Mono‐ and Bis[pyrazolylthiazoles]

“…Furthermore, attention has been increasingly paid to the synthesis of bis‐heterocyclic compounds in recent years, because of their diverse activities, especially, as antitumor and as antimicrobial .…”