Reactionswith excess TMSOTf (1.5 equiv) led to an improved conversion(90%) in 50 min. We then examined other catalysts in this reaction,and to our surprise we found that copper(I) (entries 3–6) anda variety of other metals also expedite this transformation. For example,scandium(III) triflate and Rh[Cod]2Cl2 withexcess TMSOTf (1.5 equiv) afforded reasonable conversions to vinyltriflate 1a in less than 1 h (entries 7 and 8). However,optimal results were obtained with Zn(OTf)2 leading toa 91% conversion in 20 min (entry 9).
T1 - Synthesis of polysiloxanes bearing cyclic carbonate side chains. Dielectric properties and ionic conductivities of lithium triflate complexes
Synthesis essay triflate Vinyl ..
A (Z)-vinyl (diisopropyl)carbamate group, generated from a Hoppe allylation reaction, was easily transformed either into the corresponding (Z)-vinyl phosphate or (Z)-vinyl triflate function in good yield and high selectivity. It was also shown that the resulting (Z)-vinyl triflate compound could be utilized successfully in palladium-catalysed coupling reactions with vinyl-, phenyl- and acetylenic tin derivatives, without loss of the (Z)-geometry of the double bond.
13-12-2017 · Synthesis of α-Trifluoromethylated ..
A new synthesis of aryl vinyl ketones is described. The acylation of active aromatics with the complex of β-ethylsulfanylpropionyl fluoride 1 and boron trifluoride leads to formation of 1-aryl-3-(ethylsulfanyl)propan-1-ones. Subsequent methylation with methyl triflate and elimination with an aqueous solution of KHCO3 results in formation of aryl vinyl ketones in 86-99% yield.
Synthesis of Ethenyl(phenyl)iodonium Triflate, [H2C …
AB - The reaction of vinyl inflates with a slight excess of triphenylphosphine and 1-3 mol % Pd(PPh3)4 in refluxing THF results in the formation of the corresponding vinyltriphenylphosphonium triflate salts in good yield. A wide variety of salts, including cyclic ones, can be prepared. Unlike past syntheses of these compounds, pure stereoisomeric starting triflates stereoselectively yield stereoisomeric products. The current synthesis is especially useful for the preparation of Z isomers.
Synthesis of Ethenyl(phenyl)iodonium Triflate, ..
A convenient method for the preparation of alkynes and alkynyl esters from ketones and β-keto esters is described which involves the formation of vinyl triflates, followed by elimination with tetrabutylammonium fluoride trihydrate, to give alkynes. Unlike established elimination methods, the method requires neither a strong base nor anhydrous conditions.
A formal synthesis of perhydrohistrionicotoxin
Acid Showdown! The first catalytic ring expansion of vinyl oxetanes to 3,6-dihydro-2H-pyrans is described. Copper(II) triflate emerged as the best catalyst for this new transformation, which has broad scope as demonstrated by the eighteen examples included. The symmetric vinyl oxetane substrate can be asymmetrically desymmetrized when using either chiral Lewis or Brønsted acids as catalysts.