enantioselective formal [4+2] cycloadditions of 3‐nitroindoles are presented. By using 3‐nitroindoles in combination with an organocatalyst, chiral dihydrocarbazole scaffolds are formed in moderate to good yields (up to 87 %) and enantioselectivities (up to 97 % ee). The reaction was extended to include enantioselective [4+2] cycloadditions of 3‐nitrobenzothiophene. The reaction proceeds through a [4+2] cycl
Organocatalytic Cascade Reactions for the Diversification of Thiopyrano‐Piperidone Fused Rings Utilizing Trienamine Activation
作者:Suhas Balasaheb Mitkari、Alberto Medina‐Ortíz、José Luis Olivares‐Romero、Miguel A. Vázquez、Eduardo Peña‐Cabrera、Clarisa Villegas Gómez、David Cruz Cruz
DOI:10.1002/chem.202004553
日期:2021.1.7
An aminocatalytic privileged diversity‐oriented synthesis (ApDOS) strategy utilizing trienamine catalysis for the construction of diverse and complex thiopyrans‐piperidone fused rings through a thia‐Diels–Alder/nucleophilic ring‐closing sequence by using dithioamides as activated heterodienophiles is reported. Following this strategy, a super cascade reaction to assemble nine fused rings can be achieved
Organocatalytic Cascade Reactions: Towards the Diversification of Hydroisochromenes and Chromenes through Two Different Activation Modes
作者:David Cruz Cruz、Rasmus Mose、Clarisa Villegas Gómez、Stine V. Torbensen、Martin S. Larsen、Karl Anker Jørgensen
DOI:10.1002/chem.201403505
日期:2014.9.1
The organocatalytic enantioselective syntheses of functionalized hydroisochromenes and chromenes by trienamine‐mediated [4+2]‐cycloaddition/nucleophilic ring‐closing and iminium‐ion/aminal‐mediated oxa‐Michael/Michael/nucleophilic ring‐closing with 2‐nitroallylic alcohols are presented. The corresponding cycloadducts, with up to five stereocenters, are formed in good yield and excellent enantioselectivities
介绍了由三烯胺介导的[4 + 2]-环加成/亲核开环和亚胺离子/氨基介导的氧杂-Michael / Michael /亲核与2-硝基烯丙醇成环的功能化氢异色酮和色烯的有机催化对映选择性合成。 。形成具有最多五个立体中心的相应的环加合物,具有良好的产率和优异的对映选择性。已经证明了所得产物的合成应用。
Taming of Thioketones: The First Asymmetric Thia-Diels-Alder Reaction with Thioketones as Heterodienophiles
作者:Joanna Hejmanowska、Marcin Jasiński、Grzegorz Mlostoń、Łukasz Albrecht
DOI:10.1002/ejoc.201601307
日期:2017.2.3
An efficient application of aryl and hetaryl thioketones as dienophiles in the enantioselective thia-Diels-Alder reaction is presented for the first time. It has been demonstrated that thioketones of that type can serve as useful heterodienophiles in the aminocatalytic, trienamine-mediated [4+2]-cycloadditions with 2,4-dienals. This enantioselective approach (up to 99:1 er) is efficiently promoted
A Direct Organocatalytic Enantioselective Route to Functionalized
<i>trans</i>
‐Diels–Alder Products Having the Norcarane Scaffold
作者:Casper L. Barløse、Niklas L. Østergaard、René S. Bitsch、Marc V. Iversen、Karl Anker Jørgensen
DOI:10.1002/anie.202106598
日期:2021.8.9
organocatalysis with excellent selectivity, high yield and up to five contiguous stereocenters is presented. The reaction concept integrates the halogen effect and a novel discovered pseudo-halogen effect to direct an endo-selective, secondary-amine catalyzed Diels–Alder reaction allowing for the subsequent formation of trans-Diels–Alder cycloadducts featuring the norcarene scaffold. The methodology relies on