69622-42-0Relevant articles and documents
Organocatalytic Enantioselective Synthesis of Atropisomeric Aryl-p-Quinones: Platform Molecules for Diversity-Oriented Synthesis of Biaryldiols
Chen, Ye-Hui,Li, Heng-Hui,Li, Shaoyu,Tan, Bin,Xiang, Shao-Hua,Zhang, Xiao
supporting information, p. 11374 - 11378 (2020/05/25)
Presented here is a class of novel axially chiral aryl-p-quinones as platform molecules for the preparation of non-C2 symmetric biaryldiols. Two sets of aryl-p-quinone frameworks were synthesized with remarkable enantiocontrol by means of chiral phosphoric acid catalyzed enantioselective arylation of p-quinones by central-to-axial chirality conversion. These aryl-p-quinones were then used to access a wide spectrum of highly functionalized non-C2 symmetric biaryldiols with excellent retention of the enantiopurity.
DFT-Guided Phosphoric-Acid-Catalyzed Atroposelective Arene Functionalization of Nitrosonaphthalene
Ding, Wei-Yi,Yu, Peiyuan,An, Qian-Jin,Bay, Katherine L.,Xiang, Shao-Hua,Li, Shaoyu,Chen, Ying,Houk,Tan, Bin
, p. 2046 - 2059 (2020/07/13)
Guided by computational design, Tan and colleagues disclose a chiral phosphoric-acid-catalyzed asymmetric functionalization of naphthalenes with nitroso as the activating and directing group. This nucleophilic aromatic substitution reaction allows divergent access to two types of axially chiral arylindole frameworks with wide substrate generality under excellent enantiocontrol and, more importantly, offers a facile approach to the privileged NOBIN (2-amino-2′-hydroxy-1,1′-binaphthyl) structures. DFT calculations illustrate the plausible reaction pathway and provide additional insights into the origins of enantioselectivity.Functionalization of arenes represents the most efficient approach for constructing a core backbone of important aryl compounds. Compared with the well-developed electrophilic aromatic substitution and transition-metal-catalyzed C–H activation, nucleophilic aromatic substitution remains challenging because of the lack of a convenient route for rapid conversion of the σH adduct to other stable and versatile intermediates in situ. Guided by computational design, we were able to realize asymmetric nucleophilic aromatic substitution by introducing a nitroso group on naphthalene via chiral phosphoric acid catalysis. This strategy enables efficient construction of atropisomeric indole-naphthalenes and indole-anilines with excellent stereocontrol. Density functional theory (DFT) calculations provide further insights into the origins of enantioselectivity and the reaction mechanisms. The successful application in the synthesis of NOBINs (2-amino-2′-hydroxy-1,1′-binaphthyl) extends the utility of this strategy.Highly efficient conversion of inexpensive and readily available arene materials into high-value-added chiral molecules is of great importance in modern synthetic chemistry given the enormous potential of such structures in functional materials, pharmaceuticals, and other relevant chemical industries. Organocatalytic nucleophilic aromatic substitution enabled by an azo group offers an effective approach to enantioselective functionalization of naphthalene C–H bonds featuring an intramolecular oxidation of an unstabilized σH adduct. Premised on density functional theory (DFT) calculations, nitroso has emerged as another promising activating and oxidative group, whose synthetic potential is substantiated in the atroposelective synthesis of several groups of representative biaryl atropisomers processed by a chiral phosphoric acid catalyst. The success of this reaction explicitly exemplifies the ability of computational tools to streamline organic synthesis with intensified robustness in the disclosed strategy.
Carbonylation of various organolithium reagents. A novel approach to heterocycles via intramolecular trapping of aromatic acyllithiums
Smith, Keith,El-Hiti, Gamal A.,Pritchard, Gareth J.,Hamilton, Anna
, p. 2299 - 2303 (2007/10/03)
Doubly lithiated N-pivaloylanilines react smoothly with carbon monoxide at 0°C to give 3-tert-butyl-3-hydroxy-2,3-dihydroindol-2-ones in good yields. Similarly, carbonylation of doubly lithiated 4-pivaloylamino- and 2-pivaloylaminopyridines at 0°C affords the corresponding 5-aza- and 7-aza-3-tert-butyl-3-hydroxy-2,3-dihydroindol-2-ones, respectively, in good yields. However, carbonylation of doubly lithiated N-pivaloyl-o-toluidines takes a different course due to direct intramolecular cyclisation of the dilithio reagents to afford 2-tert-butylindoles without uptake of carbon monoxide.