6049-50-9Relevant academic research and scientific papers
Activation of the hypervalent fluoroiodane reagent by hydrogen bonding to hexafluoroisopropanol
Minhas, Harsimran K.,Riley, William,Stuart, Alison M.,Urbonaite, Martyna
supporting information, p. 7170 - 7173 (2018/10/24)
Hexafluoroisopropan-2-ol (HFIP) is an excellent solvent for promoting fluorinations with the hypervalent fluoroiodane reagent 1 and crucially, it removes the need for transition metals or TREAT-HF activators. The fluoroiodane reagent 1 was used in HFIP to monofluorinate 1,3-ketoesters and to fluorocyclise unsaturated carboxylic acids in excellent yields under mild reaction conditions.
Catalytic addition-elimination reactions towards butenolides
Brown, Danielle M.,Niyomura, Osamu,Wirth, Thomas
experimental part, p. 1026 - 1035 (2009/04/06)
A wide range of selenium-containing reagents are known to undergo addition - elimination reactions under different reaction conditions. We report on selenium electrophiles, which are regenerated under the reaction conditions employed, and therefore only catalytic amounts of these reagents are necessary.
Predominant 1,2-insertion of styrene in the Pd-catalyzed alternating copolymerization with carbon monoxide
Nozaki,Komaki,Kawashima,Hiyama,Matsubara
, p. 534 - 544 (2007/10/03)
The regioselectivity of styrene insertion to an acyl-Pd bond was studied by NMR in (i) a stoichiomeric reaction and (ii) a copolymerization with CO. In the stoichiometric reaction of styrene with [(CH3CO)Pd-(CH3CN){(R,S)-BINAPHOS}] ·[B{3,5-(CF3)2C6 H3}4], both 1,2-and 2,1-products were given. To mimic the real polymerization conditions, a polyketone-substituted complex [{CH3(CH2CHCH3CO)n}Pd{(R,S)-BINAP HOS}]·[B(3,5-(CF3)2C6 H3)4] (n ≈ 14) was prepared. When this polymer-attached Pd species was treated with styrene, the 1,2-insertion product was the only detectable species. Thus, exclusive 1,2-insertion is demonstrated to be responsible for the styrene-CO copolymerization, in sharp contrast to the predominant 2,1-insertion with conventional nitrogen ligands. Chain-end analysis revealed that β-hydride elimination took place from the 2,1-complex but not from the 1,2-complex. Thus, once 2,1-insertion occurs, rapid β-hydride elimination proceeds to terminate the polymerization, as is common to the other phosphorus-ligand systems. The resulting Pd-H species re-initiates the copolymerization, as was proven by MALDI-TOF mass analysis of the product copolymers.
Chemoselectivity of rhodium carbenoids. A comparison of the selectivity for O-H insertion reactions or carbonyl ylide formation versus aliphatic and aromatic C-H insertion and cyclopropanation
Cox,Moody,Austin,Padwa
, p. 5109 - 5126 (2007/10/02)
A range of diazocarbonyl compounds 1-9 containing two different functional groups has been prepared, and their rhodium(II) catalysed decomposition studied as a means of probing the chemoselectivity of carbenoid intermediates. The results indicate that wereas O-H insertion reactions predominate over cyclopropanation and aromatic insertion reactions, carbonyl ylide formation vs other competing processes is more finely balanced, and is catalyst dependent.
Alternatives to α-Diazo Ketones for Tandem Cyclization-Cycloaddition and Carbenoid-Alkyne Metathesis Strategies. Novel Cyclic Enol-Ether Formation via Carbonyl Ylide Rearrangement Reactions
Fairfax, David J.,Austin, David J.,Xu, Simon L.,Padwa, Albert
, p. 2837 - 2844 (2007/10/02)
Attempts to form carbonyl ylides from free carbenes derived from diazirines or diazo compounds lacking electron-withdrawing substituents resulted in azine formation or Wolff rearrangement, respectively.Iodonium ylides proved to be a possible alternative to α-diazo compounds for metallocarbenoid generation, similar reactivity being observed for both systems.Studies into the rearrangement chemistry of carbonyl ylides provided a novel cyclic enol-ether synthesis via a 1,4-hydrogen shift process.
