Highly Stereoselective Formation of 1,3-Dioxolanes by Photocatalytic Ring Opening Reactions of a-Epoxyketones in Acetone Solution Using 1-Benzyl-2,4,6-triphenylpyridinium Tetrafluoroborate (NBTPT)
作者:Xiaojun Zeng、Wenhao Yan、Samson B. Zacate、Aijie Cai、Yufei Wang、Dongqi Yang、Kundi Yang、Wei Liu
DOI:10.1002/anie.202006048
日期:2020.9.14
stable bioisostere of an amino (NH2) group. Therefore, methods that can rapidly convert an NH2 group into a CF2H group would be of great value to medicinal chemistry. We report herein an efficient Cu‐catalyzed approach for the conversion of alkyl pyridinium salts, which can be readily synthesized from the corresponding alkyl amines, to their alkyl difluoromethane analogues. This method tolerates a broad
The Formal Cross‐Coupling of Amines and Carboxylic Acids to Form sp
<sup>3</sup>
–sp
<sup>3</sup>
Carbon–Carbon Bonds
作者:Zirong Zhang、Tim Cernak
DOI:10.1002/anie.202112454
日期:2021.12.20
acid C−C coupling would be a valuable addition to the synthetic toolbox of carbon–carbon bond-formingreactions. Using miniaturized high-throughput experimentation, we have developed the first amine–acid cross-coupling to form C(sp3)−C(sp3) bonds based on preactivation of the building blocks and nickelcatalysis.
Biocompatible Photoinduced Alkylation of Dehydroalanine for the Synthesis of Unnatural α-Amino Acids
作者:José A. C. Delgado、José T. M. Correia、Emanuele F. Pissinati、Márcio W. Paixão
DOI:10.1021/acs.orglett.1c01781
日期:2021.7.2
A site-selective alkylation of dehydroalanine to access protected unnatural amino acids is described. The protocol is characterized by the wide nature of alkyl radicals employed, mild conditions, and functional group compatibility. This protocol is further extended to access peptides, late-stage functionalization of pharmaceuticals, and enantioenriched amino acids.
Catalyst‐Free Deaminative Functionalizations of Primary Amines by Photoinduced Single‐Electron Transfer
作者:Jingjing Wu、Phillip S. Grant、Xiabing Li、Adam Noble、Varinder K. Aggarwal
DOI:10.1002/anie.201814452
日期:2019.4.16
The use of pyridinium‐activated primary amines as photoactive functional groups for deaminative generation of alkyl radicals under catalyst‐free conditions is described. By taking advantage of the visible light absorptivity of electron donor–acceptor complexes between Katritzky pyridiniumsalts and either Hantzsch ester or Et3N, photoinduced single‐electron transfer could be initiated in the absence
Ni-Catalyzed deaminative hydroalkylation of internal alkynes
作者:Ze-Fan Zhu、Jia-Lin Tu、Feng Liu
DOI:10.1039/c9cc05385a
日期:——
A regioselective cis-hydroalkylation of internal alkynes with readily prepared Katritzky pyridinium salts for the synthesis of tri-substituted alkenes is described. This reaction is the first example of a metal-catalyzed hydroalkylation of an alkynevia C–N bond activation of an amine. The reaction demonstrates broad scope and functional group tolerance, allowing access to desired products with high