Rearrangement thio

Keywords Sulfiu [3,3]-sigmatropic rearrangements Thio-Claisen Sulfoxides Sulfilimines... 

Unlike oxygen based Claisen rearrangements, thio-Qaisens do not give the intermediate thiophenol, but the cyclized material directly. The t-butylsulfonamide 24 could be deprotected with acid, giving off isobutylene. The primary sulfonamide 35 proved to be versatile interm ate. It can be oxidized to the sulfone 28 or it can be dehydrogenated to the benzothiophene 21. In turn, 21 can be oxidized with hydrogen peroxide to the vinylsulfone 28. All these sulfonamides can be used to prepare tied-back sulfonylureas. 

Sigmatropic rearrangement (thio-Claisen) of allyl enesulphides, obtained after basic alkylation of thioketones or enethiols, has led to y-unsaturated thioketones (11), to an enethiol (8 R = allyl), and to an enethiol in the indole series. ... 

Conversion of 5-allylthioimidates into /V-allylthioamides is catalyzed by Pd(Il). 2-Allylthiopyridine (820) is converted into the less stable l-allyl-2-thio-pyridone 821 owing to Pd complex formation[509], Claisen rearrangement of 2-(allylthio)pyrimidin-4-(3//)-one (822) affords the A-l-allylation product 823 as the main product rather than the A -3-allylation product 824[510] The smooth rearrangement of the allylic thionobenzoate 825 to the allyl thiolo-benzoate 826 is catalyzed by both PdCl2(PhCN)2 and Pd(Ph3P)4 by different mechanisms[511],... 

Another indole/oxindole synthesis achieves the critical ortho-substitution by Sommelet-Hauser rearrangement of an anilinosiilfonium ion intermediate. Use of P-thioketones (G = R, an alkyl group) generates 2-substituted indoles, whereas P-thioesters (G = OR) lead to oxindoles. In each case, a 3-thio substituent must be removed by desulfuri2ation. 

Indole, 4,5,6,7-tetrahydro-4,7-dioxo-structure, 4, 303 Indole, tetrahydro-3-methyl-synthesis, 4, 109 Indole, 2-(2-thienyl)-nitration, 4, 211 Indole, 3-thio-synthesis, 4, 368 Indole, 2-thioalkyl-synthesis, 4, 152 Indole, 3-thiocyano-synthesis, 4, 368 Indole, 1-tosyloxy-rearrangement, 4, 302 Indole, 1,2,3-trialkyl-Mannich reactions, 4, 228 Indole, 3-(tricyanovinyl)-nucleophilic addition reactions, 4, 281 reactions... 

Lumazine, 1,3,6,7,8-pentamethyl-5,6,7,8-tetrahydro-rearrangement, 3, 308 Lumazine, 5,6,7,8-tetrahydro-autoxidation, 3, 308 oxidation, 3, 306 Lumazine, 1,3,6,7-tetramethyl-ring transformations, 3, 308 Lumazine, 1,3,5,6-tetramethyl-5,6,7,8-tetrahydro-synthesis, 3, 316 Lumazine, 2-thio-reactions, 3, 300 sulfurization, 3, 296 Lumazine, 4-thio-methylation, 3, 299 reactions, 3, 300 Lumazine, 1,3,7-trimethyl-acylation, 3, 290 Lumazine, 1,6,7-trimethyl-bromination, 3, 302 synthesis, 3, 295 Lumazine, 3,6,7-trimethyl-... 

Purines, N-alkyl-N-phenyl-synthesis, 5, 576 Purines, alkylthio-hydrolysis, 5, 560 Mannich reaction, 5, 536 Michael addition reactions, 5, 536 Purines, S-alkylthio-hydrolysis, 5, 560 Purines, amino-alkylation, 5, 530, 551 IR spectra, 5, 518 reactions, 5, 551-553 with diazonium ions, 5, 538 reduction, 5, 541 UV spectra, 5, 517 Purines, N-amino-synthesis, 5, 595 Purines, aminohydroxy-hydrogenation, 5, 555 reactions, 5, 555 Purines, aminooxo-reactions, 5, 557 thiation, 5, 557 Purines, bromo-synthesis, 5, 557 Purines, chloro-synthesis, 5, 573 Purines, cyano-reactions, 5, 550 Purines, dialkoxy-rearrangement, 5, 558 Purines, diazoreactions, 5, 96 Purines, dioxo-alkylation, 5, 532 Purines, N-glycosyl-, 5, 536 Purines, halo-N-alkylation, 5, 529 hydrogenolysis, 5, 562 reactions, 5, 561-562, 564 with alkoxides, 5, 563 synthesis, 5, 556 Purines, hydrazino-reactions, 5, 553 Purines, hydroxyamino-reactions, 5, 556 Purines, 8-lithiotrimethylsilyl-nucleosides alkylation, 5, 537 Purines, N-methyl-magnetic circular dichroism, 5, 523 Purines, methylthio-bromination, 5, 559 Purines, nitro-reactions, 5, 550, 551 Purines, oxo-alkylation, 5, 532 amination, 5, 557 dipole moments, 5, 522 H NMR, 5, 512 pJfa, 5, 524 reactions, 5, 556-557 with diazonium ions, 5, 538 reduction, 5, 541 thiation, 5, 557 Purines, oxohydro-IR spectra, 5, 518 Purines, selenoxo-synthesis, 5, 597 Purines, thio-acylation, 5, 559 alkylation, 5, 559 Purines, thioxo-acetylation, 5, 559... 

Tetrazole, l-(p-substituted phenyl)-antimicrobial activity, 5, 835 Tetrazole, 5-thio-rearrangements, 5, 823 Tetrazole, 2-thioacyl-reactions, 5, 109 Tetrazole, 5-(o-tolyl)-tautomerism, 5, 804 Tetrazole, 5-(p-tolyl)-dipole moments, 5, 795 tautomerism, 5, 804 Tetrazole, 5-(trimethylsilylamino)-synthesis, 5, 832 Tefrazolecarbaldehydes reactions, 5, 820 Tetrazole-5-carbaldehydes reactions, 5, 820 Tetrazolecarbonitriles reactions, 5, 820 Tetrazole carbonyl compounds reactions, 5, 820 Tetrazolecarboxylic acid, 5-aryl-acidity, 5, 816... 

Substituted TMM complexes also cycloadd to aldehydes in the presence of a tin cocatalyst such as MesSnOAc and MesSnOTs [31]. Reaction of 2-heptenal with methyl precursor (6) gave a mixture of methylenetetrahydrofurans (68) and (69). This regioselectivity is reversed with 10-undecenal and methyl precursor (5), where adduct (70) now predominates over (71). As in the carbocyclic system, the phenylthio group also functions as a regiocontrol element in reaction with cyclohexyl aldehyde. The initially formed adduct (72) eliminates the element of thio-phenol on attempted allyl rearrangement, and the overall process becomes a cycloaddition approach to furans (Scheme 2.21) [20]. 

Similar to the well-known thio-Claisen rearrangement of allyl aryl sulfides211 and sulfonium salts212, the thio-Claisen rearrangement of allyl aryl sulfoxides has also been reported213. For example, heating of allyl 2-naphthyl sulfoxide (147) at 120 °C for 2h in dimethylformamide resulted in quantitative isomerization to the dihydronaphthothio-... 

Thio-Claisen rearrangement 746-748 Thioketene 5-oxides photolysis of 878 reactions of 277 Thiolane dioxides formula of 382 NMR spectra of 460 reactions of 604 synthesis of 461 Thiolane oxides 747 formula of 382 IR spectra of 461 synthesis of 461, 462, 752 Thiolanes, photolysis of 881 Thiolene dioxides formula of 382 NMR spectra of 460 reactions of 464, 465 synthesis of 461 Thiolene oxides formula of 382 synthesis of 461, 746 Thiols... 

The reaction of crotonaldehyde and methyl vinyl ketone with thiophenol in the presence of anhydrous hydrogen chloride effects conjugate addition of thiophenol as well as acetal formation. The resulting j3-phenylthio thioacetals are converted to 1-phenylthio-and 2-phenylthio-1,3-butadiene, respectively, upon reaction with 2 equivalents of copper(I) trifluoromethanesulfonate (Table I). The copper(I)-induced heterolysis of carbon-sulfur bonds has also been used to effect pinacol-type rearrangements of bis(phenyl-thio)methyl carbinols. Thus the addition of bis(phenyl-thio)methyllithium to ketones and aldehydes followed by copper(I)-induced rearrangement results in a one-carbon ring expansion or chain-insertion transformation which gives a-phenylthio ketones. Monothioketals of 1,4-diketones are cyclized to 2,5-disubstituted furans by the action of copper(I) trifluoromethanesulfonate. ... 

A recent paper [44] shows that the treatment of silyl thioketones 68 with lithium diethylphosphite proceeds via a thiophiUc attack followed by a thio-phosphate mercaptophosphonate (69 70) carbanionic rearrangement and the migration of the silyl group from the carbon to the sulfur atom leading to the S-silylated sulfanylphosphonate carbanion 71. The last step represents the first example of the thia-Brook rearrangement (Scheme 18). 

A thio-Claisen rearrangement174 was used for the regioselective synthesis of thiopyrano[2,3-b]pyran-2-ones and thieno[2,3-b]pyran-2-ones (Eq. 12.76). A convenient method for the aromatic amino-Claisen rearrangement of N-(l,l-disubstituted-allyl)anilines led to the 2-allylanilines being produced cleanly and in high yield by using a catalytic amount of p-toluenesulfonic acid in acetonitrile/water (Eq. 12.77).175... 

The 5-thio-substituted l,3,4-thiadiazole-2(377)-thiones 75 react with iV-methyl-C-phenylnitrilimine in a regiospe-cific 1,3-dipolar cycloaddition to form not the expected cycloadducts 76 but rather the rearranged products 77 and 78 in 16-28% yields (Scheme 6) <1998AJC499>. 

The allylation of thiadiazole-2-thione 114 with ally 1 bromide gave as the main product the N-allyl derivative 115 with trace amounts of the corresponding S-derivative 116 (Equation 36) <2003CHE228>. Furthermore, it was shown that refluxing the thiadiazole 116 in DMF (3h) gave thiadiazole-2-thione 115 via a thio-Claisen rearrangement. 

Diastereoselective asymmetric thio-Claisen rearrangement has been carried out by the reaction of thioamides with allyllic bromide (Scheme 37).76... 

Dithiophosphoric acids, (RO)2PS2H, have been used for the thionation of carbonyl groups in certain aldehydes, ketones, amides, esters, thio-carboxylates and other organics.163 The mechanism for this reaction proceeds via a reversible nucleophilic attack of the thioacid on the carbonyl compound, which can then rearrange by way of a four-membered PSCO cyclic intermediate into the desired C=S containing molecule and thiophosphoric acid (Equation 81).163... 

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