1322775-85-8Relevant academic research and scientific papers
Directing group assisted nucleophilic substitution of propargylic alcohols via o -quinone methide intermediates: Br??nsted acid catalyzed, highly enantio- and diastereoselective synthesis of 7-alkynyl-12a-acetamido-substituted benzoxanthenes
Saha, Satyajit,Schneider, Christoph
, p. 648 - 651 (2015)
BINOL-based, chiral phosphoric acids catalyze the substitution of 1-(o-hydroxyphenyl)propargylic alcohols with enamides to furnish 7-alkynyl-12a-acetamido-substituted benzo[c]xanthenes and related heterocycles in a one-pot operation with excellent diastereo- and enantioselectivity. Ambient reaction temperature, operationally simple reaction conditions, low catalyst loading, high yields, and excellent stereocontrol are attractive features of this process and make it a highly practical and versatile transformation.
Synthesis of γ-benzopyranone by TfOH-promoted regioselective cyclization of o-alkynoylphenols
Yoshida, Masahito,Fujino, Yuta,Doi, Takayuki
supporting information; experimental part, p. 4526 - 4529 (2011/10/09)
Regioselective cyclization of o-alkynoylphenols forming γ-benzopyranones has been demonstrated. Trifluoromethanesulfonic acid (TfOH) induced 6-endo cyclization of o-alkynoylphenols without forming 5-exo cyclized benzofuranone derivatives to provide the corresponding γ-benzopyranones in high yields.
Regioselective synthesis of flavone derivatives via DMAP-catalyzed cyclization of o-alkynoylphenols
Yoshida, Masahito,Fujino, Yuta,Saito, Koya,Doi, Takayuki
experimental part, p. 9993 - 9997 (2012/02/06)
A catalytic amount of DMAP promoted cyclization of o-alkynoylphenols via a 6-endo cyclization mode leading to flavone derivatives in high yields without forming 5-exo cyclized aurone derivatives. Utilizing this method, methoxy substituted flavone and alkyl substituted γ-benzopyranone derivatives were synthesized.
