Heterocyclic fused 2,5-dihydrothiophene S,S-dioxides as precursors to heterocyclic o-quinodimethanes
作者:Lynne M. Chaloner、Andrew P.A. Crew、Paul M. O'Neill、Richard C. Storr、Michael Yelland
DOI:10.1016/s0040-4020(01)80480-4
日期:1992.1
5-bischloromethylthiophene-2-carboxylate by reaction with sodium sulfide and oxidation. Pyrazole fused analogues 15 and 16 (R = Me and COPh) were prepared from 3-phenylsulfonyl-2,5-dihydrothiophene S,S-dioxide by cycloaddition of diazomethane, base induced aromatisation and N-substitution of the sulfone 14. Reaction of 3-acetyl-4-phenylthio-2,5-dihydrothiophene S,S-dioxide with hydrazine and interception of
2,5-Dihydrothiophene 5,5-dioxides 8 and 6 have been obtained by interception of flash-pyrolytically produced 2,3-dihydro-2,3-bis(methylene)thiophene with sulfur dioxide and from methyl 4,5-bischloromethylthiophene-2-carboxylate by reaction with sodium sulfide and oxidation. Pyrazole fused analogues 15 and 16 (R = Me and COPh) were prepared from 3-phenylsulfonyl-2,5-dihydrothiophene S,S-dioxide by cycloaddition
Facile synthesis of 4,6-dihydrothieno[3,4-b]thiophene 5,5-dioxide. A synthetic equivalent of 2,3-dihydro-2,3-dimethylenethiophene
作者:Ta-Shue Chou、Chung-Ying Tsai
DOI:10.1039/c39910001287
日期:——
4,6-Dihydrothieno[3,4-b]thiophene 5,5-dioxide 4, a stable precursor of 2,3-dihydro-2,3-dimethylenethiophene 3, conveniently prepared from 4-bromo-3-chloro-2,3-dihydrothiophene S,S-dioxide, can easily be alkylated and loses SO2 upon heating so that 4 serves as a useful synthetic equivalent of 3.
4,6-二氢噻吩并[3,4- b ]噻吩-5,5-二氧化物4,2,3-二氢-2,3- dimethylenethiophene的稳定前体3,方便地从4-溴-3-氯-2-制备3-二氢噻吩S(S-二氧化物)很容易被烷基化,加热时失去SO 2,因此4可用作3的有用合成当量。
Ring substituted thieno-o-quinodimethanes via electrophilic substitution reactions of thieno-3-sulfolene
作者:Ta-shue Chou、Chia-Tien Wang
DOI:10.1016/0040-4020(96)00725-9
日期:1996.9
Thieno-3-sulfolene 6 has been treated with several electrophiles at very mild temperatures to give substituted derivatives 7a-d. Thermolysis of these substituted 3-sulfolenes at 170–210°C leads to the formation of the corresponding o-quinodimethanes 8a-d which can be trapped as Diels-Alder cycloadducts.
The generation of 2,3-dihydro-2,3-bis-(methylene)thiophenes from 4,6-dihydrothieno[3,4-b]thiophene 5,5-dioxides
作者:A.P.A. Crew、G. Jenkins、R.C. Storr、M. Yelland
DOI:10.1016/s0040-4039(00)88841-3
日期:1990.1
A Cyclization Approach toward Five-Membered Heteroaromatic<i>o</i>-Quinodimethanes<i>via</i>Fused-3-Sulfolenes
作者:Ta-Shue Chou、Chung-Ying Tsai、Shwu-Jiuan Lee
DOI:10.1002/jccs.199700045
日期:1997.6
AbstractA general strategy involving the zincation of 4‐bromo‐3‐chloro‐2‐sulfolene, in situ condensation with an α‐heterosubstituted acetaldehyde, and subsequent cyclization reaction as the key steps toward the synthesis of furano‐ and thieno‐3‐sulfolenes is described. These fused‐3‐sulfolenes are demonstrated to be good precursors for the corresponding o‐quinodimethanes.