Silver-Catalyzed Cyclization of Propargylic Amides to Oxazolines
作者:Valerie H. L. Wong、Andrew J. P. White、T. S. Andy Hor、King Kuok Mimi Hii
DOI:10.1002/adsc.201500610
日期:2015.12.14
is observed in the cyclization of propargylicamides catalyzed by bis(pyridyl)silver(I) complexes, with an unexpected reversal of electronic demand to the analogous NH addition reaction. The catalyst was found to be effective for internal alkyne substrates, offering exclusive selectivity for the 5-exo-dig product. Differences in selectivity profile between gold- and silver-catalyzed processes are highlighted
Amine-boranes as Dual-Purpose Reagents for Direct Amidation of Carboxylic Acids
作者:P. Veeraraghavan Ramachandran、Henry J. Hamann、Shivani Choudhary
DOI:10.1021/acs.orglett.0c03184
日期:2020.11.6
Amine-boranes serve as dual-purpose reagents for direct amidation, activating aliphatic and aromatic carboxylicacids and, subsequently, delivering amines to provide the corresponding amides in up to 99% yields. Delivery of gaseous or low-boiling amines as their borane complexes provides a major advantage over existing methodologies. Utilizing amine-boranes containing borane incompatible functionalities
A cesium carbonate promoted, transition metal and halogen‐free 5‐exo‐dig type cyclization reaction for the synthesis of oxazoles and imidazoles has been developed.
Synthesis, Structure and Catalytic Activity of NHC-Ag<sup>I</sup>
Carboxylate Complexes
作者:Valerie H. L. Wong、Sai V. C. Vummaleti、Luigi Cavallo、Andrew J. P. White、Steven P. Nolan、King Kuok Mimi Hii
DOI:10.1002/chem.201601762
日期:2016.9.5
A general synthetic route was used to prepare 15 new N‐heterocyclic carbene (NHC)–AgI complexes bearing anionic carboxylate ligands [Ag(NHC)(O2CR)], including a homologous series of complexes of sterically flexible ITent ligands, which permit a systematic spectroscopic and theoretical study of the structural and electronic features of these compounds. The complexes displayed a significant ligand‐accelerated
Iodine/Visible Light Photocatalysis for Activation of Alkynes for Electrophilic Cyclization Reactions
作者:Yuliang Liu、Bin Wang、Xiaofeng Qiao、Chen-Ho Tung、Yifeng Wang
DOI:10.1021/acscatal.7b00799
日期:2017.6.2
Photocatalytic organic synthesis needs photocatalysts to initiate the reactions and to control the reaction paths. Available photocatalytic systems rely on electron transfer or energy transfer between the photoexcited catalysts and the substrates. We explore a concept based on the photopromoted catalyst coupling to the substrate and the phototriggered catalyst regeneration by elimination from the catalytic