121507-63-9Relevant academic research and scientific papers
Synthesis of 2H-chromenes in ionic liquid solvents
Kabalka, George W.,Venkataiah, Bollu,Das, Bhaskar C.
, p. 2194 - 2196 (2004)
Vinylboronic acids react with o-hydroxyaryl aldehydes in room temperature ionic liquids in the presence of secondary amines to generate 2H-chromenes.
Glycerol as an efficient medium for the Petasis borono-mannich reaction
Rosholm, Tomi,Gois, Pedro M. P.,Franzen, Robert,Candeias, Nuno R.
, p. 39 - 46 (2015/03/04)
The multicomponent Petasis borono-Mannich (PBM) reaction is a useful tool for the preparation of complex molecules in a single step from boronic acids, aldehydes/ketones, and amines. Here, we describe the use of glycerol in the PBM reaction of salicylalde
Metalloradical approach to 2H -chromenes
Paul, Nanda D.,Mandal, Sutanuva,Otte, Matthias,Cui, Xin,Zhang, X. Peter,De Bruin, Bas
, p. 1090 - 1096 (2014/02/14)
Cobalt(III)-carbene radicals, generated through metalloradical activation of salicyl N-tosylhydrazones by cobalt(II) complexes of porphyrins, readily undergo radical addition to terminal alkynes to produce salicyl-vinyl radical intermediates. Subsequent hydrogen atom transfer (HAT) from the hydroxy group of the salicyl moiety to the vinyl radical leads to the formation of 2H-chromenes. The Co(II)-catalyzed process can tolerate various substitution patterns and produces the corresponding 2H-chromene products in good isolated yields. EPR spectroscopy and radical-trapping experiments with TEMPO are in agreement with the proposed radical mechanism. DFT calculations reveal the formation of the salicyl-vinyl radical intermediate by a metalloradical-mediated process. Unexpectedly, subsequent HAT from the hydroxy moiety to the vinyl radical leads to formation of an o-quinone methide intermediate, which dissociates spontaneously from the cobalt center and easily undergoes an endocyclic, sigmatropic ring-closing reaction to form the final 2H-chromene product.
Kinetic resolution in asymmetric epoxidation using iminium salt catalysis
Bulman Page, Philip C.,Appleby, Louise F.,Chan, Yohan,Day, David P.,Buckley, Benjamin R.,Slawin, Alexandra M. Z.,Allin, Steven M.,McKenzie, Michael J.
, p. 8074 - 8082 (2013/09/12)
The first reported examples of kinetic resolution in epoxidation reactions using iminium salt catalysis are described, providing up to 99% ee in the epoxidation of racemic cis-chromenes.
Synthesis of 2-substituted 2H-chromenes using potassium vinyltrifluoroborates
Liu, Fei,Evans, Todd,Das, Bhaskar C.
, p. 1578 - 1581 (2008/09/18)
2H-Chromenes were synthesized from salicylaldehyde using potassium vinylic borates in the presence of secondary amines. We synthesized these 2H-chromene derivatives as a part of an ongoing project to develop inhibitors for TGF-β receptors. Potassium vinyl
A NOVEL SYNTHESIS OF FLAV-3-ENES BY CLAISEN REARRANGEMENT
Subramanian, Rajaram Sankara,Balasubramanian, Kalpattu Kuppusamy
, p. 6797 - 6800 (2007/10/02)
1-Arylprop-2-ynyl aryl ethers (6) undergo a facile Claisen rearrangement in N,N-diethylaniline/o-dichlorobenzene to give flav-3-enes in good yields.
