In(OTf)<sub>3</sub>-Catalyzed Synthesis of 2,3-Dihydro-1<i>H</i>-benzo[<i>e</i>]indoles and 2,3-Dihydrobenzofurans via [3 + 2] Annulation
作者:Shuxuan Liu、Yu Zang、Hai Huang、Jianwei Sun
DOI:10.1021/acs.orglett.0c02729
日期:2020.11.6
An In(OTf)3-catalyzed intermolecular [3 + 2] annulation for the synthesis of 2,3-dihydro-1H-benzo[e]indoles and 2,3-dihydrobenzofurans from readily available substrates has been achieved. This approach takes advantage of oxetane and para-quinone methide as important functional units in the key intermediate. β-Naphthylamines and phenols have been demonstrated as excellent reaction partners.
已实现了一种由In(OTf)3催化的分子间[3 + 2]环合反应,用于从易于获得的底物中合成2,3-二氢-1 H-苯并[ e ]吲哚和2,3-二氢苯并呋喃。该方法利用氧杂环丁烷和对苯二甲酰甲烷作为关键中间体中的重要功能单元。β-萘胺和苯酚已被证明是极好的反应伴侣。
Brønsted Acid‐Catalyzed Enantioselective Cycloisomerization of Arylalkynes
作者:Julien Gicquiaud、Baptiste Abadie、Kalyan Dhara、Murielle Berlande、Philippe Hermange、Jean‐Marc Sotiropoulos、Patrick Y. Toullec
DOI:10.1002/chem.202003783
日期:2020.12.9
alkyne‐containing substrate catalyzed by chiral Brønsted acids was achieved. The use of the 2‐hydroxynaphthyl substituent on the alkyne as a directing group constituted the key parameter enabling both efficient regioselective protonation of the carbon–carbon triple bond and chiral induction. The key cationic intermediate could be depicted either as a cationic vinylidene ortho‐quinonemethide or a stabilized vinyl
α-Nitro-α,β-Unsaturated Ketones: An Electrophilic Acyl Transfer Reagent in Catalytic Asymmetric Friedel–Crafts and Michael Reactions
作者:Chandrakanta Parida、Rajendra Maity、Subas Chandra Sahoo、Subhas Chandra Pan
DOI:10.1021/acs.orglett.9b02310
日期:2019.9.6
α-nitro-α,β-unsaturated ketones as efficient electrophilic acyl transfer reagents, and they were employed in Friedel-Crafts as well as in Michael reactions. The desired acyl transfer products of these reactions were obtained in high yields with high to excellent enantioselectivities with t-leucine-derived squaramide catalyst under mild reaction conditions. Few applications including a synthesis of the isoxazoline
Organocatalytic Asymmetric Dearomatization Reaction for the Construction of Axially Chiral Urazole Embedded Naphthalenones
作者:Subhas Pan、Chandrakanta Parida、Siddharth K. Dave、Kousik Das
DOI:10.1002/adsc.202300080
日期:——
Herein we disclose a catalytic asymmetric dearomatization reaction of β-naphthols with 4-aryl-1,2,4-triazole-3,5-diones. A chiral phosphoric acid with spiro motif was found to be effective for this reaction. The chiral urazole embedded naphthalenones having both axial and central chirality were obtained in good to high yields (70–85%) with high diastereo- and enantioselectivities (>20:1, 8–96% ees)