Synthesis of benzofused cyclobutaoxepanones <i>via</i> intramolecular annulation of <i>o</i>-cinnamyl chalcones
作者:Meng-Yang Chang、Min-Chen Tsai
DOI:10.1039/d1ob00058f
日期:——
Intramolecular stereoselective annulation of o-cinnamyloxy chalcones provides two kinds of tricyclic benzofused cyclobutaoxepanones via the synthesized routes of DABCO/NBS (1,4-diazabicyclo[2.2.2]octane/N-bromosuccinimide)-mediated Baylis–Hillman type cyclization or low-pressure mercury (LP Hg) lamp-promoted photocontrolled [2 + 2] cycloaddition. Diversified reaction conditions have been investigated
4-tetrahydro[1]benzopyrano(or naphtho[1′,2′:5,6]pyrano)[4,3-c]pyrazoles. The reaction of 1 with methylhydrazine sulfate gave the corresponding 2-methyl derivatives. Analogous intramolecular [3++2] cycloadducts were obtained from the reaction of 2′-(alkenyloxy)acetophenones with arylhydrazine hydrochlorides. Intermolecular [3++2] cycloadducts were also obtained from a reaction mixture of 1-naphthaldehyde, arylhydrazine
Addition of halide to π-bond directly from aqueous NaX solution: a general strategy for installation of two different functional groups
作者:Palash Pandit、Krishnanka S. Gayen、Saikat Khamarui、Nirbhik Chatterjee、Dilip K. Maiti
DOI:10.1039/c1cc11685a
日期:——
Activation of Ï-bond with organic Lewis acid and cationic surfactant mediated direct transfer of halides to alkyne and alkene are demonstrated to afford α,α-dihaloketones and other valuable synthons with outstanding selectivities.
A domino synthetic approach for new, angular pyrazol- and isoxazol-heterocycles using [DBU][Ac] as an effective reaction medium
作者:Tushar R. Sutariya、Balvantsingh M. Labana、Bhagyashri D. Parmar、Narsidas J. Parmar、Rajni Kant、Vivek K. Gupta
DOI:10.1039/c5ra00493d
日期:——
Some new, angular pyrazol- and isoxazol-heterocycles have been synthesized by the reaction of pyrazolone/isoxazolone with typical ketone-based substrates—O-alkenyloxy/alkynyloxy-acetophenones.
photocatalysis and biocatalysis allows for the repurposing of the ‘ene’-reductase enzyme GluER to achieve the enantioselectivesynthesis of benzo-fused heterocycles, and various benzoxepinones, chromanone and indanone were specifically afforded in high yields with good to excellent enantioselectivities after protein engineering of GluER.