Herein we describe the PhI(OAc)2-mediated 1,1- and 1,2-difunctionalization of alkenes with N-tosyl amino alcohols to form oxazolidine and morpholine derivatives. This transformation was realized under mild reaction conditions and allows application to various substrates furnishing the multi-substituted oxazolidines and morpholines with yields up to 98%. A deuterium-labeling experiment was carried out
using hypervalent iodine reagent. A new m-CPBA mediated geminal aminooxygenation is also reported. A novel reagent-switch for the control of migrating group by controlling the two independent geminal addition paths is developed. Deuteriumlabelling studies and the control studies have provided unambiguous evidences for the phenyl migration and hydride migration in the oxidative geminal difunctionalization
An anti-Markovnikov geminal oxyamination of styrenyl alkenes in an intermolecular fashion using the umpolung strategy mediated by the bromoniumion is reported. Isotope labeling studies confirm the migration of the phenyl group in the semipinacol rearrangement.
Copper‐Catalyzed N−F Bond Activation for Uniform Intramolecular C−H Amination Yielding Pyrrolidines and Piperidines
作者:Daniel Bafaluy、José María Muñoz‐Molina、Ignacio Funes‐Ardoiz、Sebastian Herold、Adiran J. de Aguirre、Hongwei Zhang、Feliu Maseras、Tomás R. Belderrain、Pedro J. Pérez、Kilian Muñiz
DOI:10.1002/anie.201902716
日期:2019.6.24
The dual function of the N−F bond as an effective oxidant and subsequent nitrogen source in intramolecular aliphatic C−H functionalization reactions is explored. Copper catalysis is demonstrated to exercise full regio‐ and chemoselectivity control, which opens new synthetic avenues to nitrogenated heterocycles with predictable ring sizes. For the first time, a uniform catalysis manifold has been identified
2,2-Difunctionalization of Alkenes via Pd(II)-Catalyzed Aza-Wacker Reactions
作者:Luke D. Elliott、Joe W. Wrigglesworth、Brian Cox、Guy C. Lloyd-Jones、Kevin I. Booker-Milburn
DOI:10.1021/ol102956x
日期:2011.2.18
N-Ts and N-Boc derivatives of 1,2-diamines and 1,2-amino alcohols are shown to undergo efficient Pd(II)-catalyzed aza-Wacker reactions with a large range of electron-deficient alkenes. The resulting enamine intermediate generally undergoes cyclization with the second heteroatom to form 1,3-heterocycles. The sequence facilitates the rapid synthesis of saturated oxazolidines, imidazolidines, and their derivatives. Use of N-L-valinol derivatives results in highly diastereoselective reactions, where the net stereochemical outcome diverges between N-Ts and N-Boc.