Enantioselective Oxidative Coupling of β-Ketocarbonyls and Anilines by Joint Chiral Primary Amine and Selenium Catalysis
作者:Wanting Chen、Yanni Wang、Xueling Mi、Sanzhong Luo
DOI:10.1021/acs.orglett.9b02636
日期:2019.10.18
An enantioselective primary amine-catalyzed total N-selective nitroso aldol reaction (N-NA) was achieved through the oxidation of primary aromatic amines to the corresponding nitrosoarenes catalyzed by selenium reagents and 30% H2O2. This protocol provides a facile and highly efficient access to α-hydroxyamino carbonyls bearing chiral quaternary centers under exceedingly mild and green reaction conditions
通过硒试剂和30%H 2 O 2催化伯芳族胺氧化为相应的亚硝基芳烃,可实现对映选择性伯胺催化的总N选择性亚硝基醛醇缩合反应(N -NA)。该方案可在极其温和和绿色的反应条件下,通过高度化学和对映体控制,轻松而高效地接近带有手性季中心的α-羟氨基羰基。
Synthesis of Di(hetero)arylamines from Nitrosoarenes and Boronic Acids: A General, Mild, and Transition-Metal-Free Coupling
作者:Silvia Roscales、Aurelio G. Csákÿ
DOI:10.1021/acs.orglett.8b00473
日期:2018.3.16
The synthesis of di(hetero)arylamines by a transition-metal-free cross-coupling between nitrosoarenes and boronicacids is reported. The procedure is experimentally simple, fast, mild, and scalable and has a wide functional group tolerance, including carbonyls, nitro, halogens, free OH and NH groups. It also permits the synthesis of sterically hindered compounds.
The Mills reaction and cyclization of readily available 2‐aminobenzyl alcohols and nitrosobenzenes using thionyl bromide provided 2H‐indazoles in up to 88 % yields. In the metal‐free process, acetic acid played a crucial role for the both Mills reaction and cyclization. A brominated 2H‐indazole could also be obtained through the one‐pot sequence.
Gold‐catalyzed [4+2] Annulations of Dienes with Nitrosoarenes as 4 π Donors: Nitroso‐Povarov Reactions
作者:Ching‐Nung Chen、Rai‐Shung Liu
DOI:10.1002/anie.201903615
日期:2019.7.15
This work reports the first success of the nitroso‐Povarov reaction, involving gold‐catalyzed [4+2] annulations of nitrsoarenes with substituted cyclopentadienes. In this catalytic sequence, nitrosoarenes presumably attack gold‐π‐dienes by a 1,4‐addition pathway, generating allylgold nitrosonium intermediates to complete an intramolecular cyclization. Acyclic dienes are also applicable substrates,
Development of a [2 + 2]-Nitroso/Alkene Cycloaddition Using Sodium Tetrakis[3,5-bis(trifluoromethyl)phenyl]borate Catalyst: Controlled Chemoselectivity of Two Equilibrating Isomeric Intermediates
作者:Jia-Xuan Chen、Prakash D. Jadhav、Ching-Nung Chen、Rai-Shung Liu
DOI:10.1021/acs.orglett.1c01987
日期:2021.8.20
Sodium tetrakis[3,5-bis(trifluoromethyl)-phenyl]borate (NaBArF) catalyzes the [2 + 2] cycloaddition of 1,4-disubstituted cyclopenta-1,3-dien-2-yl esters with nitrsobenzene in toluene, affording two isolable regioisomers of 6-oxa-7-azabicyclo[3.2.0] heptanes, which thermally rearrange into the same 4-aminocyclopent-1-en-3-ones. In the case of 4-substituted cyclopenta-1,3-dien-2-yl esters, their initial