111752-77-3Relevant academic research and scientific papers
A ring expansion-annulation strategy for the synthesis of substituted azulenes. Preparation and suzuki coupling reactions of 1-azulenyl triflates
John L Jr., Kane,Shea, Kevin M.,Crombie, Aimee L.,Danheiser, Rick L.
, p. 1081 - 1084 (2001)
(matrix presented) A new strategy for the synthesis of substituted azulenes is reported, based on the reaction of β′-bromo-α-diazo ketones with rhodium carboxylates The key transformation involves intramolecular addition of a rhodium carbenoid to an arene π-bond, electrocyclic ring opening, β-elimination, tautomerization, and trapping to produce 1-hydroxyazulene derivatives. The synthetic utility of the method is enhanced by the ability of the triflate derivatives to participate in Suzuki coupling reactions, as illustrated in a synthesis of the antiulcer drug egualen sodium (KT1-32).
Ring expansion-annulation strategy for the synthesis of substituted azulenes and oligoazulenes. 2. Synthesis of azulenyl halides, sulfonates, and azulenylmetal compounds and their application in transition-metal-mediated coupling reactions
Crombie, Aimee L.,Kane Jr., John L.,Shea, Kevin M.,Danheiser, Rick L.
, p. 8652 - 8667 (2007/10/03)
A "ring expansion-annulation strategy" for the synthesis of substituted azulenes is described based on the reaction of β'-bromo- α-diazo ketones with rhodium carboxylates. The key transformation involves an intramolecular Buechner reaction followed by β-elimination of bromide, tautomerization, and in situ trapping of the resulting 1-hydroxyazulene as a carboxylate or triflate ester. Further synthetic elaboration of the azulenyl halide and sulfonate annulation products can be achieved by employing Heck, Negishi, Stille, and Suzuki coupling reactions. Reaction of the azulenyl triflate 84 with pinacolborane provides access to the azulenylboronate 91, which participates in Suzuki coupling reactions with alkenyl and aryl iodides. The application of these coupling reactions to the synthesis of biazulenes, terazulene 101, and related oligoazulenes is described, as well as the preparation of the azulenyl amino acid derivative 110.
Reactions of Carboxylic Acid Derivatives with Superoxide
Forrester, Alexander R.,Purushotham, Vemeshetti
, p. 945 - 951 (2007/10/02)
The mechanisms of the reactions of superoxide with carboxylic esters, acyl peroxides, and the acyl chlorides of α- and β-bromocarboxylic acids have been investigated.Experimental evidence is presented supporting the view that (a) conversion of an ester into its carboxylic acid does not proceed via the corresponding acyl peroxide; (b) conversion of acyl peroxide into carboxylic acid by superoxide involves either electron transfer to or an SN2 reaction on the peroxidic group; (c) α-bromoacyl chlorides with superoxide give the corresponding aldehyde via a cyclic peroxidic intermediate.
