Catalytic 1,2-Dicyanation of Alkynes by Palladium(II) under Aerobic Conditions
作者:Shigeru Arai、Takashi Sato、Atsushi Nishida
DOI:10.1002/adsc.200900334
日期:2009.8
various alkynes in the presence of trimethylsilyl cyanide (TMSCN) by palladium(II) catalysis under aerobicconditions is investigated. This reaction includes two cyanation pathways, syn- and anti-cyanopalladation to alkynes that are activated by Pd(II). High syn-selectivity was observed in the reaction using terminal alkynes that have bulky substituents at a propargyl position and aliphatic internal
hydrocyanation of terminal alkynes is described. A tosylamide functionality at the propargyl position was the most suitable group for controlling the regiochemistry for CCN bond formation as well as rate enhancement. A gram-scale synthesis was achieved by minimizing the catalyst loading to 2 mol%. The major HCN adduct could be transformed to the corresponding indoline through construction of a benzylic quaternary
Gold-Catalyzed 1,2-Oxyalkynylation of <i>N</i>-Allenamides with Ethylnylbenziodoxolones
作者:Somsuvra Banerjee、Beeran Senthilkumar、Nitin T. Patil
DOI:10.1021/acs.orglett.8b03651
日期:2019.1.4
redox-neutral Au(I)/Au(III) catalytic pathway, was enabled in an attempt to exhaust the EBX reagents atom-economically by putting the nucleophilic carboxylate part of EBXs to appropriate use. This constitutes the first example for gold-catalyzed β-alkynylation of N-allenamides to construct highly valuable 1,3-enynes. The potential of the sequence is further documented by some follow-up transformations
α‐Cationic Phospholes: Synthesis and Applications as Ancillary Ligands
作者:Tim Johannsen、Christopher Golz、Manuel Alcarazo
DOI:10.1002/anie.202009303
日期:2020.12.7
A series of structurally differentiated α‐cationic phospholes containing cyclopropenium, imidazolium, and iminium substituents has been synthesized by reaction of chlorophosphole 1 with the corresponding stable carbenes. Evaluation of the donor properties of these compounds reveals that their strong π‐acceptor character is heavily influenced by the nature of the cationic group. The coordination chemistry
Facile synthesis of novel 3-bromo-1,2-dihydroquinolines by the intramolecularcyclization of N-tosyl-N-propargyl anilines catalyzed by Pd(OAc)2 in conjunction with CuBr2 and LiBr.