Intramolecular Trapping of Allenylzincs by Carbonyl Groups
作者:Suribabu Jammi、Julien Maury、Jean-Simon Suppo、Michèle P. Bertrand、Laurence Feray
DOI:10.1021/jo4022293
日期:2013.12.20
Allenylzinc formed via oxygen-promoted zinc/iodineexchangebetween propargyl iodides and diethylzinc can be trapped by intramolecular reaction with various electrophiles such as aldehydes, ketones, esters, carbamates, and imides. Potentially useful building blocks were obtained in high yields.
Theoretical Support for the Involvement of a Radical Pathway in the Formation of Allenylzincs from Propargyl Iodides and Dialkylzincs: Influence of Zinc Coordination
作者:Suribabu Jammi、Dominique Mouysset、Didier Siri、Michèle P. Bertrand、Laurence Feray
DOI:10.1021/jo302704g
日期:2013.2.15
undergo homolytic substitution at zinc. The stabilization of allenylzinc derivatives by chelation, made possible by the selection of appropriate ortho-substituted 3-phenylalkynyl iodides as precursors, was shown to influence the regioselectivity of their addition to aldehydes and ketones. The more stabilized the chelated allenylzinc intermediate, the higher the ratio of homopropargylic alcohols.
palladium/chiral norbornene cooperative catalysis. The obtained C–N axialchirality originates from the preformed transient C–C axialchirality with high fidelity. A variety of C–N axiallychiral phenanthridinones are obtained in excellent enantioselectivities (44 examples, up to >99% ee). This method can be applied for the construction of two stereogenic axes via double atroposelective C–H arylation
Reduction of Electron‐Deficient Alkenes Enabled by a Photoinduced Hydrogen Atom Transfer
作者:Natalia A. Larionova、Jun Miyatake Ondozabal、Xacobe C. Cambeiro
DOI:10.1002/adsc.202000751
日期:2021.1.19
Direct hydrogen atom transfer from a photoredox‐generated Hantzsch ester radical cation to electron‐deficient alkenes has enabled the development of an efficient formal hydrogenation under mild, operationally simple conditions. The HAT‐driven mechanism is supported by experimental and computational studies. The reaction is applied to a variety of cinnamate derivatives and related structures, irrespective
A strategy for assembling biaryls linked through a medium‐sized ring is herein presented. π‐Complexation of fluoroarenes to chromium tricarbonyl activates the molecule towards both C−H activation and nucleophilic aromatic substitution without covalently altering the molecular connectivity of the arene. The construction of bridged biaryl molecules with 6–10‐membered core rings is achieved through a