Topic
Annulation
About: Annulation is a research topic. Over the lifetime, 10152 publications have been published within this topic receiving 189701 citations.
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TL;DR: 3-Sulfenylindoles can be efficiently prepared in moderate to good yields from 2-(1-alkynyl)benzenamines and disulfides using the palladium/ air catalytic systems and provides a useful route to the synthesis of fipronil analogues.
Abstract: 3-Sulfenylindoles can be efficiently prepared in moderate to good yields from 2-(1-alkynyl)benzenamines and disulfides using the palladium/ air catalytic systems. The study also provides a useful route to the synthesis of fipronil analogues.
92 citations
TL;DR: A Lewis-base-catalyzed enantioselective [3 + 3] annulation reaction of Morita–Baylis–Hillman (MBH) carbonates with α-arylidene pyrazolinones is described, affording the pyrazolone-fused spirocyclohexenes bearing an all-carbon quaternary stereocenter in high yields with good to excellent diastereoselectivities and excellent enantiOSElectivities.
Abstract: A Lewis-base-catalyzed enantioselective [3 + 3] annulation reaction of Morita–Baylis–Hillman (MBH) carbonates with α-arylidene pyrazolinones is described, affording the pyrazolone-fused spirocyclohexenes bearing an all-carbon quaternary stereocenter in high yields with good to excellent diastereoselectivities and excellent enantioselectivities.
92 citations
91 citations
TL;DR: This extended Pummerer annulation/cross-coupling sequence is powerful enough to synthesize biologically active natural products as well as highly fluorescent benzofuran derivatives.
Abstract: Operationally simple, efficient, and widely applicable Pummerer annulations of simple phenols with ketene dithioacetal monoxides, with the aid of trifluoroacetic anhydride, have been shown to provide a variety of benzofurans having a methylthio group at the 2-position. Subsequent and newly developed nickel-catalyzed arylation at the methylthio group culminates in diversity-oriented synthesis of multisubstituted benzofurans. Our extended Pummerer annulation/cross-coupling sequence is powerful enough to synthesize biologically active natural products as well as highly fluorescent benzofuran derivatives.
91 citations
TL;DR: The Rh-catalyzed direct annulation of an aldehyde with an alkyne leading to indenone was achieved and tolerates a series of functional groups, such as methoxyl, acetylamino, fluoro, trifluoromethyl, methoxycarbonyl, chloro, and bromo groups.
91 citations