Synthesis of 3-Benzazepines by Metal-Free Oxidative C-H Bond Functionalization-Ring Expansion Tandem Reaction
作者:Andrea Gini、Julia Bamberger、Javier Luis-Barrera、Mercedes Zurro、Rubén Mas-Ballesté、José Alemán、Olga García Mancheño
DOI:10.1002/adsc.201600985
日期:2016.12.22
A metal‐free synthesis of biologically important benzazepines is achieved through a single synthetic operation involving an oxidative C–H bond functionalization and ring expansion with diazomethanes as key reagent. This represents a new, strong methodology for the straightforward construction of the seven‐ring N‐heterocyclic structures under mild conditions using a 2,2,6,6‐tetramethylpiperidine 1‐oxyl
Water-Enabled Catalytic Asymmetric Michael Reactions of Unreactive Nitroalkenes: One-Pot Synthesis of Chiral GABA-Analogs with All-Carbon Quaternary Stereogenic Centers
作者:Jae Hun Sim、Choong Eui Song
DOI:10.1002/anie.201611466
日期:2017.2.6
new catalytic reactions for otherwise unreactive substrate systems. Under the “on water” reaction conditions, extremely unreactive β,β‐disubstituted nitroalkenes smoothly underwent enantioselective Michael addition reactions with dithiomalonates using a chiral squaramide catalyst, affording both enantiomers of highly enantioenriched Michael adducts with all‐carbon‐substituted quaternarycenters. The
Substrate Scope Evaluation of the Enantioselective Reduction of β-Alkyl-β-arylnitroalkenes by Old Yellow Enzymes 1-3 for Organic Synthesis Applications
作者:Mattia Bertolotti、Elisabetta Brenna、Michele Crotti、Francesco G. Gatti、Daniela Monti、Fabio Parmeggiani、Sara Santangelo
DOI:10.1002/cctc.201500958
日期:2016.2
to bioreduction, to define the synthetic potential of this enantioselective reaction in the preparation of chiral fine chemicals. The versatility of the resulting nitroalkanes as chiral building blocks is shown by reducing the nitro group into a primary amine and by converting it into a carboxylic acid moiety by Meyerreaction.
A highly efficient, iridium-catalyzed, enantioselectivehydrogenation of β,β-disubstituted nitroalkenes has been developed. Using a complex consisting of iridium and (S,S)-f-spiroPhos as the catalyst, a variety of β,β-disubstituted nitroalkenes were successfully hydrogenated to the corresponding chiral nitroalkanes with excellent enantioselectivities (up to 98% ee) and high turnover numbers (TON=1000)
An iridium complex with a newly prepared chiral spiro amino-phosphine ligand efficiently catalyzed the hydrogenation of both [small beta]-aryl-[small beta]-methyl-nitroalkenes and [small beta]-alkyl-[small beta]-methyl-nitroalkenes to the corresponding saturated nitroalkanes, which represents the first report...