Dithieno

Dithienobenzene synthesis, 4, 720 Dithieno[3,2-fc 2,3-/]borepin molecular dimensions, 1, 633 Dithienoborepins stability, 1, 660... 

More recently, OFETs were made with a dimer of another condensed molecule. dithieno[3,2-/j 2, 3 -c/ lhiophene 100, which presents a very similar structure lo that of benzodithiophene, except that the central benzene ring is changed lo a... 

Two types of symmetric fused dithienophospholes exist, which differ according to the position of the S atoms as illustrated by compounds (53) [54] and (54) [50] (Scheme 15). The a A -dithieno[3,2-fo 2, 3 -d]phosphole (55) has recently been considered as a potential subunit for the construction of n-conjugated materials [55] (Scheme 15). Exploitation of the reactivity of the nucleophilic P-atom of (55) allows access to derivatives (56) and complexes (57) (Scheme 15). The absorption and emission behaviour of these species varies with the nature of the P-moieties. Upon oxidation of the P-centre of (55),bathochromic shifts of Ajnax Aejn were observed Aj ax 344 nm for (55) and ca. 373 nm for (56), and Agjn 422 nm for (55) and ca. 460 nm for (56) [55]. These results nicely illustrate... 

Many substituted thiophenes have also been electrochemically polymerised [19,54,399-405] (Table 4) as have thiophene dimers [21,37,55,251,400,406], trimers [21, 83,407], and tetramers [256,406], with the thiophene dimer giving rise to higher quality films than does the monomer [37, 395,408]. Several polycyclic monomers including a thiophene ring have also been polymerised [408-416], as have a series of compounds consisting of two thiophene rings linked by a polyene chain (Fig. 23c). The polymerisation of dithieno-thiophene (Fig. 23d) results in a polymer which shows remarkable similarity to polythiophene in its properties [409,410,414],... 

The naming of these three heterocyclic fused (5 5 5) ring systems has been carried out according to the IUPAC system of nomenclature. Some examples are given as follows compound la (Table 1) is named (3-hydroxy-4-methoxyphenylthieno[2,3-3]pyrrolizin-8-one. Compound 15a (Table 2) is dithieno[3,2-3 2, 3 - 1thiophene. Compound 23a (Table 2) is dithieno[3,2-3 2, 3 - 1pyrrole. Compound 20a (Table 2) is dithicno[3,2-3 2, 3 -r/]thiophene-4,4-dio ide. Compound 13b (Table 2) is 3,4-dimethyldithieno[3,2-3 2, 3 -i/]thiophene-7,7-dioxide. Compound 38 (Table 4) is fM, r, r-10-azatricyclo[5.2.1.01 10]deca-2,5,8-triene. Compound 39 (Table 4) is cis,cis, m-10-azatricyclo[5.2.1.01 10]deca-2,8-diene. The nomenclature of compound 40 (Table 4) is 1,4,7 triaza tricy-clo[5.2.1.01,10]decane. 

Poly(iV-substituted dithieno[3,2-3 2, 3 -rf pyrroles (PDTPs) 167a,b) <2005MM4545>, a class of soluble (chiral) conjugated polymers with a stable oxidized state, were prepared by an oxidative coupling by FeClj in chloroform under an argon atmosphere. The crude material was reduced with hydrazine to afford compound 167 (Scheme 19) <2005MM4545>. 

Synthesis of dithieno[2,3-A2,3-,7]thiophene derivatives 122 has been accomplished through the Heck reaction of 3-(4-bromo-2-thienyl)acrylic acid 302 to afford 3-(2,4-thienylene)diacrylic acid 303 which was cyclized with thionyl chloride and a catalytic amount of pyridine to the dichloride 120 in 75% yield (Scheme 56) <2005MOL279>. 

An improved synthesis of dithieno[3,2-A2, 3 -<7]thiophene 15a has been achieved from 2,3-dibromothiophene 304 (Scheme 57). Lithiation of 2,3-dibromothiophene 304 using -butyllithium followed by oxidative coupling with cupric chloride provided 3,3 -dibromo-2,2 -bithiophene 305 in 79% yield. Treatment of 305 with 2 equiv of -butyllithium in ether at —78 °C under nitrogen for 40 min and then adding benzenesulfonic acid thioanhydride and leaving the reaction mixture to reach room temperature afforded dithieno[3,2-A2, 3 -<7]thiophene 15a in 70% yield <2002TL1553>. 

The synthesis of dithieno[3,2-3 2, 3 -<7]thiophene 15a has also been accomplished using a combination of the methods described by De Jong et al. and Brandsma . In this approach, 3-bromothiophene 298 was lithiated and the 3-lithiothiophene 308 species reacted with sulfur dichloride to give di(3-thienyl)sulfide 309. Ring closure of 309 was effected using -butyllithium followed by addition of cupric chloride to yield dithieno[3,2-3 2, 3 -. 

A general synthesis of dibenzo-annelated dithieno[3,Z-b Z, 3 - thiophene 18 has been reported from bis(o-hydro-xyl)diacetylenes. This cyclization constructs a fused tricyclic skeleton in one pot. The subsequent dechalconization with copper powder produces a series of thiophene and selenophene-based heterocenes (Scheme 64) <20050L5301>. 

Af-Functionalized dithieno[3,Z-b Z, 3 - pyrrole (DTP) 23 analogues have been synthesized from 3-bromothiophene 298 <2003JOC2921>. 3-Bromothiophene 298 which reacts with amines in the presence of NaO Bu to give a mixture of alkyl... 

The structures of 1,4-dithiins such as dithieno[2,3- 3, 2 -f]-l,4-dithiin have been shown previously to be nonplanar they are folded along the S-S axis <1984CHEC(4)973>. Brisse et al. have shown that iV,iV -dimethyl-l,4-dithiin-l,2 4,5-tetracarboxamide 18 and its diselenine analogue are planar (Figure 3) <2000AXC190>. 

Lithiation of the dibromodithienyl compound 464 and reaction with sulfur and subsequent oxidation yielded the tetramethyl substituted dithieno[3,Z-c.Z, 3 - ][l,2]dithiin 465 (Equation 126) <1997T7509>. 

However, the yield for the unsubstituted analogue was only 19%, due to competing lithiation reactions. Le Coustumer and Catel have recently demonstrated a high-yielding route to the unsubstituted dithieno[l,2]dithiin 467 via the dithiolate (Equation 127) <2006PS( 181) 191 >. 

The dithieno[3,2-6 2, 3 -<7 phosphole 63 has been designed as a very sensitive material for detection of fluoride ions <06OL495>. Cationic dithieno[3,2-6 2, 3 -<7 phospholes alkylated at the phosphorus atom have also been prepared for application as building blocks... 

Thus, many polymers with different conductivity were synthesized. To cite a few, these are polythiophene [158], 3-methylthiophene [159], polymers of 3-thiophene-acetic acid and methyl 3-thiophene-acetate [160], poly(2,5-thienylenevinylene) [161], poly(benzo[h]-thiophene) [162], poly(naphto[2,3-c]thio-phene) [163], poly(dithieno[3,2-h 2, 3 -fii]-thiophene) [164], poly(3- -hexylthiophene)... 

Gronowitz and co-workers prepared dithieno[6,6 ]tropones by cycli-zation of pure (Z)-l,2-dithienylethenecarboxylic acids via acid chlorides in the presence of SnCU [73CS(3)165]. The corresponding synthesis of... 

A new class of photochromic diarylethenes containing thieno[3,2-b] thiophenes, dithieno[3,2-b 2, 3 -d]thiophene (08CC5203), and dithieno [3,2-fc 2, 3 -d]pyrroles (09CEJ10005) with photoswitchable luminescence properties were synthesized by Suzuki cross-coupling reactions (Scheme 48). 

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