23077-27-2Relevant articles and documents
Dearomatizing Spiroannulation Reagents: Direct Access to Spirocycles from Indoles and Dihalides
Liddon, John T. R.,Rossi-Ashton, James A.,Taylor, Richard J. K.,Unsworth, William P.
, p. 3349 - 3353 (2018)
Unfunctionalized indoles can be directly converted into 3,3′-spirocyclic indolenines and indolines upon reaction with electrophilic dihalides in the presence of t-BuOK/BEt3. This double C-C bond forming reaction, which simultaneously generates a quaternary spirocyclic center, typically proceeds in high yield and has good functional group tolerance. In contrast to existing dearomatizing spirocyclization approaches, there is no need to prepare a prefunctionalized aromatic precursor, enabling faster access to valuable spirocyclic products from simple, commercially available aromatics in one step.
Oxidation of Nonactivated Anilines to Generate N-Aryl Nitrenoids
Deng, Tianning,Mazumdar, Wrickban,Ford, Russell L.,Jana, Navendu,Izar, Ragda,Wink, Donald J.,Driver, Tom G.
supporting information, p. 4456 - 4463 (2020/03/05)
A low-temperature, protecting-group-free oxidation of 2-substituted anilines has been developed to generate an electrophilic N-aryl nitrenoid intermediate that can engage in C-NAr bond formation to construct functionalized N-heterocycles. The exposure of 2-substituted anilines to PIFA and trifluoroacetic acid or 10 mol percent Sc(OTf)3 triggers nitrenoid formation, followed by productive and selective C-NAr and C-C bond formation to yield spirocyclic- or bicyclic 3H-indoles or benzazepinones. Our experiments demonstrate the breadth of these oxidative processes, uncover underlying fundamental elements that control selectivity, and demonstrate how the distinct reactivity patterns embedded in N-aryl nitrenoid reactive intermediates can enable access to functionalized 3H-indoles or benzazepinones.
Reactions of some Heterocyclic Quaternary Salts with Trifluoroacetic Anhydride
Bailey, A. Sydney,Ellis, J. Hilary,Harvey, Jayne M.,Hilton, Andrew N.,Peach, Josephine M.
, p. 795 - 800 (2007/10/02)
Treatment of the methiodides of 4a-methyl-1,2,3,4-tetrahydro-4aH-carbazole, 2-methyl-3H-indole-3-spirocyclopentane, 2-methylbenzothiazole, and 2-methylquinoline with trifluoroacetic anhydride afforded trifluoromethyl ketones.Some reactions of these enamin
