De Novo Ring Synthesis of Thiophenes - Thiophenes - page 6

De Novo Ring Synthesis of Thiophenes

John Arthur Joule

Abstract The principal methods for the synthesis of thiophenes from precursors
which do not contain a thiophene ring are reviewed. Where possible, recent and/or
significant examples of each method are used as illustrations.

Keywords 1,2-Dicarbonyl compound 1,3-Dicarbonyl compound 1,3-Diyne

1,3-Enyne 1,4-Diketone 1,4-Dithiin 3,4-Dihydroxythiophene

Aminothiophenes Bis(trimethylsilyl)sulfide Cadiot-Chodkiewicz coupling

Carbon disulfide Cycloaddition EDOT Gewald reaction Glaser coupling

Hinsberg reaction Lawesson's reagent McMurray reaction PEDOT

Pentaphosphorus decasulfide Quinquethiophene Stetter synthesis Stobbe reac-

tion Sulfur Sulfur dichloride Terthiophene Thiazolium ylide Thieno[2,3- b ]

thiophene Thieno[3,4- c ]thiophene Thioamide Thioglycolate Thiophene ester

Thiophenophane Vinamidinium salt Zirconacycle α -Haloketone α -Mercapto-

α 0 -Thiobisketone

ketone α , ʲ -Keto-ester (1,3-keto-ester)

Contents

1 Introduction . . ................................................................................. 8
2 Ring Synthesis of Thiophenes . .............................................................. 8
2.1 Thiophenes from 1,4-Dicarbonyl Compounds ........................................ 8
2.2 Thiophenes from 1,3-Diynes ........................................................... 13
2.3 Synthesis of 2-Amino-3-Carbonyl-Thiophenes - Gewald Synthesis . . . .............. 17
2.4 Synthesis of Thiophene-2,5-Dicarboxylic Acid Derivatives from Thiodiacetates
and 1,2-Dicarbonyl Compounds - Hinsberg Synthesis . .............................. 20
2.5 Synthesis of Thiophene-2-Carboxylates from Thioglycolates (2-Mercaptoacetates)
and 1,3-Dicarbonyl Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.6 Synthesis of 3,4-Disubstituted Thiophenes from α , α 0 -Thiobisketones . . . . . . . . . . . . . . . 26
2.7 Synthesis of 2-Aminothiophenes from Thioamides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28