- Chloromethyl Trimethylsilylmethyl Sulphide as a Parent Thiocarbonyl Ylide Synthon. A Simple Synthesis of Dihydro- and Tetrahydro-thiophenes
-
Chloromethyl trimethylsilylmethyl sulphide acts as a parent thiocarbonyl ylide synthon and reacts stereospecifically with activated alkenes and alkynes, catalysed by caesium fluoride, in acetonitrile at room temperature to give tetrahydro- and dihydro-thi
- Hosomi, Akira,Matsuyama, Yumiko,Sakurai, Hideki
-
-
Read Online
- Synthesis of dicarboxylic acid derivatives of [60]fullerene using Diels- Alder reaction with bis(methylene)butanedioates
-
3-Sulfolene-3,4-dicarboxylates effective for generation of bis(methylene)butanedioates were applied to [4+2] cycloaddition reaction of C60 to give fullerocyclohexenedicarboxylates, among which a t-butyl ester was hydrolyzed to a dicarboxylic acid derivative, useful for further conversion into its anhydride and half-esters. (C) 2000 Elsevier Science Ltd.
- Ishida, Hiroshi,Asaji, Hirotaka,Hida, Toshiki,Itoh, Kenji,Ohno, Masatomi
-
-
Read Online
- Synthetic Entry to Polyfunctionalized Molecules through the [3+2]-Cycloaddition of Thiocarbonyl Ylides
-
Here we present a comprehensive study on the [3+2]-cycloaddition of thiocarbonyl ylides with a wide variety of alkenes and alkynes. The obtained dihydro- and tetrahydrothiophene products serve as exceptionally versatile intermediates providing access to thiophenes, dienes, dendralenes, and vic-quarternary carbon centers. The use of high-pressure conditions enables thermally unstable, sterically encumbered or moderately reactive substrates to undergo the cycloaddition under mild conditions, thereby increasing the yield by up to 58percent. In addition, we showcase its utility by the formal syntheses of the pharmaceuticals NGB 4420 and tenilapine.
- Habiger, Christoph,Haut, Franz-Lucas,Korber, Johannes Nepomuk,Müller, Thomas,Magauer, Thomas,Mayer, Peter,Speck, Klaus,Wurst, Klaus
-
supporting information
(2019/09/06)
-
- SYNTHESIS OF CANTHARIDIN
-
The invention provides synthetic methods for the preparation of cantharidin and analogs thereof. In one aspect, the invention provides an improved Diels-Alder cycloaddition to generate a key intermediate en route to cantharidin and analogs thereof. In certain embodiments, the new Diels-Alder reaction involves reacting Compound (2) in the presence of furan, and in the absence of acid or increased pressure, in an aprotic polar solvent with slight warming, to yield Compound (1) in favorable yield and exo-endo ratio. In another aspect, the invention also provides a new Diels-Alder reaction between compounds of Formula (III) and furan to yield compounds of Formula (IV), which can then be transformed into cantharidin or analogs thereof. In yet another aspect, the invention describes a new palladium-mediated carbonylation providing another key intermediate en route to cantharidin and analogs thereof. In addition to synthetic methods, present invention also provides compounds {i.e., intermediates) useful in the synthesis of cantharidin and analogs thereof. Compounds provided herein may have biological activity, and therefore may be used in the treatment of diseases or conditions {e.g., infectious diseases and skin conditions).
- -
-
Paragraph 00259; 00269
(2019/04/27)
-
- Single precursor for the synthesis of donor and acceptor units of the low band gap polymers: Synthesis of benzodithiophene and thienopyrroledione from maleic anhydride
-
An efficient route was developed to synthesize dimethyl thiophene-3,4-dicarboxylate from maleic anhydride. Dimethyl thiophene-3,4-dicarboxylate was used as a single precursor for synthesis of benzo[1,2-b:4,5-b′]dithiophene (BDT) and Thieno[3,4-c]pyrrole-4,6-dione (TPD) derivatives. BDT and TPD derivatives have been highly exploited as donor and acceptor units, respectively, to synthesize important donor-acceptor (D-A) conjugated polymers. BDT-based polymers were found to be one of the most efficient conjugated polymers for organic photovoltaic application. Synthesis of quinone precursor of the dihydroxybenzothiophene was accomplished by a new and unconventional methodology which includes reaction of 3,4-thiophene dicarboxylate with sodium hydride in THF. Dithienobenzoquinone dicarboxylate and dihydroxybenzodithiophene dicarboxylate were characterized structurally by single-crystal X-ray diffraction. Both compounds show strong π-stacking interaction and arrange in the parallel molecular sheets in the crystals.
- Kadam, Vinay S.,Patel, Arun L.,Zade, Sanjio S.
-
supporting information
p. 2608 - 2611
(2016/06/01)
-
- COMMERCIALLY VIABLE SYNTHESIS OF CANTHARIDIN AND BIOACTIVE CANTHARIDIN DERIVATIVES
-
The present disclosure provides methods for synthesizing cantharidin and cantharidin derivatives.
- -
-
Paragraph 0107
(2016/07/05)
-
- Cycloaddition approach to the curing of polyimides via precursor containing thiophene-S,S-dioxide
-
A new method for linear polymerization of maleimides via the Diels-Alder reaction has been developed. This method involves use of a new cross-linking agent, benzene-3,4-dimethylenesuccinimide, which can be generated in situ from its thiophene precursor, benzene-2,5-dihydrothiophene-3,4dicarboximide-S,S- dioxide. This new cross-linking agent is reasonably reactive, readily prepared, and stable at room temperature. A controlled molecular weight oligomer has been synthesized and applied to the polymerization to yield a highly thermal stable polyimide.
- Magyarosy, Andrew,Mohareb, Rafat M.,Ho, Jonathan Z.
-
p. 648 - 652
(2007/10/03)
-
- NEW METHOD FOR GENERATION OF THIOCARBONYL YLIDES FROM BIS(TRIMETHYLSILYLMETHYL)SULFOXIDES AND THEIR APPLICATION TO CYCLOADDITIONS
-
Thiocarbonyl ylides were generated by heating of bis(trimethylsilylmethyl)sulfoxides.Cycloadditions of the ylides in the presence of dipolarophiles proceeded smoothly to give di- or tetrahydrothiophenes.
- Aono, Masaaki,Terao, Yoshiyasu,Achiwa, Kazuo
-
p. 249 - 260
(2007/10/02)
-
- GENERATION OF THIOCARBONYL YLIDES WITH RELEASE OF DISILOXANE FROM BIS(TRIMETHYLSILYLMETHYL) SULFOXIDES
-
A novel and general method for generation of thiocarbonyl ylide by release of disiloxane from bis(trimethylsilylmethyl) sulfoxide (1) has been found.This method was also demonstrated for generation of aliphatic and aromatic thioaldehyde S-methylide.
- Aono, Masahiro,Hyodo, Chiaki,Terao, Yoshiyasu,Achiwa, Kazuo
-
p. 4039 - 4042
(2007/10/02)
-
- Functionalisation of Alkenes by a Cycloaddition-Cycloreversion Sequence. Part 2. Anionic Cycloreversion Reactions of 2,5-Dihydrothiophene Derivatives
-
The anionic cycloreversions of the 2,5-dihydrothiophene sulphonium salts (3), (7), (12), and (16) gave the thiodienes (4), (8), (13), and (17) respectively.The 2,5-dihydrothiophenes were prepared by reduction of the corresponding sulphones (which were obt
- Pettett, Michael G.,Holmes, Andrew B.
-
p. 1161 - 1166
(2007/10/02)
-