Synthesis of Carboxylic and Carbonic Ortho Esters

DeWolfe, Robert H.

doi:10.1055/s-1974-23268

Cited by 71 publications

(25 citation statements)

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“…Ref. 10), which is cleaved as described earlier 11a to form ether and ester. So, mixing of silane 2a with aminoacetal 9 in a molar ratio of 3 : 1 affords fluorosilane 4a, divinyl ether 6, and trifluoromethacrylic ester 11 in virtually quantitative yields.…”

Section: Methodsmentioning

confidence: 99%

Reaction of 1-hydrohexafluoroisobutenyloxytrimethylsilane with fluoride ion sources. 2,2,2’,2’-Tetrakis(trifluoromethyl)divinyl ether

et al. 2004

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The reaction of 1 hydrohexafluoroisobutenyloxytrimethylsilane (2a) with cesium fluoride in diglyme leads to elimination of trimethylfluorosilane to form the 1 hydrohexafluoro isobutenolate anion (3), which is silylated with trialkylchlorosilanes at the oxygen atom. In the presence of bis(trifluoromethyl)ketene N,N,O trimethylaminoacetal or N (α,α difluoro alkyl)dialkylamines, silane 2a is transformed into 2,2,2´,2´ tetrakis(trifluoromethyl)divinyl ether. The reaction of trifluoroacetic anhydride with N (1,1,2,2 tetrafluoroethyl)diethylamine affords trifluoroacetyl fluoride in quantitative yield.

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Section: Methodsmentioning

confidence: 99%

Reaction of 1-hydrohexafluoroisobutenyloxytrimethylsilane with fluoride ion sources. 2,2,2’,2’-Tetrakis(trifluoromethyl)divinyl ether

et al. 2004

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“…Transesterification (Scheme 2), reactions producing esters by catalytical alcoholysis of other esters, also play an important role in the industry, for instance in the manufacture of glycerol esters in fat chemistry (e.g., biodiesel), the transesterification of dimethyl carbonate to diethyl carbonate, or the production of polyethylene terephthalate from dimethyl terephthalate. For these reactions, the usual catalysts are Brønsted mineral acids (H 3 PO 4 , H 2 SO 4 , HCl) [24][25][26], and organic acids such as MeSO 3 H and p-toluenesulfonic acid (TsOH) [27], alkoxides such as NaOR, KOR, ROMgBr [28][29][30][31][32], Lewis bases such as 4-dimethylaminopyridine (DMAP) [33,34], 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU) [35], Lewis acids such as BX 3 [36], or AlCl 3 [37], amphoteric Catalysts 2016, 6, 128 5 of 65 compounds (compounds able to react either as acids or bases) such as Bu 3 SnOR [38][39][40][41], perfluorotin oxides [42], Al(OR) 3 [43,44], titanium oxides chlorides [45][46][47][48] or palladium oxides [49,50]. More recently, diaminocarbenes have been introduced as catalysts as well [51][52][53][54].…”

Section: Acyl Group Transfersmentioning

confidence: 99%

Organocatalysis: Fundamentals and Comparisons to Metal and Enzyme Catalysis

et al. 2016

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Catalysis fulfills the promise that high-yielding chemical transformations will require little energy and produce no toxic waste. This message is carried by the study of the evolution of molecular catalysis of some of the most important reactions in organic chemistry. After reviewing the conceptual underpinnings of catalysis, we discuss the applications of different catalysts according to the mechanism of the reactions that they catalyze, including acyl group transfers, nucleophilic additions and substitutions, and C-C bond forming reactions that employ umpolung by nucleophilic additions to C=O and C=C double bonds. We highlight the utility of a broad range of organocatalysts other than compounds based on proline, the cinchona alkaloids and binaphthyls, which have been abundantly reviewed elsewhere. The focus is on organocatalysts, although a few examples employing metal complexes and enzymes are also included due to their significance. Classical Brønsted acids have evolved into electrophilic hands, the fingers of which are hydrogen donors (like enzymes) or other electrophilic moieties. Classical Lewis base catalysts have evolved into tridimensional, chiral nucleophiles that are N-(e.g., tertiary amines), P-(e.g., tertiary phosphines) and C-nucleophiles (e.g., N-heterocyclic carbenes). Many efficient organocatalysts bear electrophilic and nucleophilic moieties that interact simultaneously or not with both the electrophilic and nucleophilic reactants. A detailed understanding of the reaction mechanisms permits the design of better catalysts. Their construction represents a molecular science in itself, suggesting that sooner or later chemists will not only imitate Nature but be able to catalyze a much wider range of reactions with high chemo-, regio-, stereo-and enantioselectivity. Man-made organocatalysts are much smaller, cheaper and more stable than enzymes.

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“…155 (35) X=O.s OSOCI H-<.+ Cl NRIR2 (34) Cl H-<.+ Cl + S02 (20) NRIR2 (21) R1=H,X=O (iv) Miscellaneous reagents A very efficient preparation of amide chlorides comprises the action of elemental chlorine on thioamides in CH2Ch or CCI4; even amide chlorides which possess electron-attracting substituents in the a-position have been prepared in this way. 7,9,143,156 DMF was converted to the corresponding iminium salt (27) by the following reagents: 5 perfluorobutyryl chloride, 2,2-dichlorobenzodioxole (36) and 2,2,2-trichlorobenzodioxaphosphole (37). (36) (37) (i) Hydrogen halides to nitriles or imidoyl halides…”

Section: (Iii) Sulfur Compoundsmentioning

confidence: 99%

“…7 . 10 A convenient route to N-unsubstituted salts (93; equation 54) is the alcoholysis of the formamide-benzoyl chloride adduct,7.10 The reaction of phenols with dimethylformamide chloride (27) …”

Section: From Halomethyleneiminium Salts and Related Compoundsmentioning

confidence: 99%

“…Orthocarbonates react with Grignard reagents to give orthocarboxylates (412; equation 193) in usually only moderate yields, because the orthoesters thus formed can react further with the Grignard reagent yielding acetals or ethers,?, 22,24,27,885,886 This side reaction can be suppressed by the use of trialkoxyacetonitriles instead of orthocarbonates. 887 From organolithium compounds and trialkoxycarbenium salts orthoesters (413) and (414) OEt C(OEt)4~Ph---;===:=---+(-OEt OEt (416) (195) The preparation of orthoesters from orthoesters by acid-catalyzed transesterification is a standard procedure, which has been reviewed several times.7.22-27 Advantageous starting compounds are the methylor ethyl-orthoesters.…”

Section: From Orthocarbonic Esters and Related Compounds (Including Tmentioning

confidence: 99%

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