Interrogating Pd(II) Anion Metathesis Using a Bifunctional Chemical Probe: A Transmetalation Switch
作者:John J. Molloy、Ciaran P. Seath、Matthew J. West、Calum McLaughlin、Neal J. Fazakerley、Alan R. Kennedy、David J. Nelson、Allan J. B. Watson
DOI:10.1021/jacs.7b11180
日期:2018.1.10
Ligand metathesis of Pd(II) complexes is mechanistically essential for cross-coupling. We present a study of halide→OH anion metathesis of (Ar)PdII complexes using vinylBPin as a bifunctional chemical probe with Pd(II)-dependent cross-coupling pathways. We identify the variables that profoundly impact this event and allow control to be leveraged. This then allows control of cross-coupling pathways
Rhenium‐Catalyzed Decarboxylative Tri‐/Difluoromethylation of Styrenes with Fluorinated Carboxylic Acid‐Derived Hypervalent Iodine Reagents
作者:Yin Wang、Yunhui Yang、Congyang Wang
DOI:10.1002/cjoc.201900296
日期:2019.12
Herein, unprecedented rhenium‐catalyzed decarboxylative oxytri‐/difluoromethylation and Heck‐type trifluoromethylation of styrenes have been developed by using hypervalent iodine(III) reagents derived from cheap, stable, and easy‐handling fluorinated carboxylic acids. Mechanistic studies revealed a radical decarboxylative trifluoromethylation pathway occurring in these reactions.
In Situ Generation of Diimide from Hydrazine and Oxygen: Continuous-Flow Transfer Hydrogenation of Olefins
作者:Bartholomäus Pieber、Sabrina Teixeira Martinez、David Cantillo、C. Oliver Kappe
DOI:10.1002/anie.201303528
日期:2013.9.23
No catalyst required! A highly efficient, catalyst‐free process to generate diimide in situfromhydrazine monohydrate and molecular oxygen for the selective reduction of alkenes has been developed. The use of a gas–liquid segmented flow system allowed safe operating conditions and dramatically enhanced this atom‐economical reaction, resulting in short processing times.
Green and Efficient: Iron-Catalyzed Selective Oxidation of Olefins to Carbonyls with O<sub>2</sub>
作者:Angela Gonzalez-de-Castro、Jianliang Xiao
DOI:10.1021/jacs.5b03956
日期:2015.7.1
A mild and operationally simple iron-catalyzed protocol for the selective aerobic oxidation of aromatic olefins to carbonyl compounds is described. Catalyzed by a Fe(III) species bearing a pyridine bisimidazoline ligand at 1 atm of O2, α- and β-substituted styrenes were cleaved to afford benzaldehydes and aromatic ketones generally in high yields with excellent chemoselectivity and very good functional
Regioselective Synthesis of Vinyl Halides, Vinyl Sulfones, and Alkynes: A Tandem Intermolecular Nucleophilic and Electrophilic Vinylation of Tosylhydrazones
作者:Devi Prasan Ojha、Kandikere Ramaiah Prabhu
DOI:10.1021/ol503114n
日期:2015.1.2
in tandem at the carbene center to install an electrophile and a nucleophile on the same carbon. This metal-free concept, which is unprecedented, has been illustrated by regioselectivesynthesis of a variety of vinyl halides, vinyl sulfones, and alkyne derivatives.