Developing asymmetric iron and ruthenium-based cyclone complexes; complex factors influence the asymmetric induction in the transfer hydrogenation of ketones
Ethynyl Benziodoxolones for the Direct Alkynylation of Heterocycles: Structural Requirement, Improved Procedure for Pyrroles, and Insights into the Mechanism
作者:Jonathan P. Brand、Clara Chevalley、Rosario Scopelliti、Jérôme Waser
DOI:10.1002/chem.201200200
日期:2012.4.27
accelerating effect of a methyl substituent in both the 3‐ and 6‐position of triisopropylsilylethynyl‐1,2‐benziodoxol‐3(1H)‐one (TIPS‐EBX) on the reaction rate was observed. Competitive experiments between substrates of different nucleophilicity, deuterium labeling experiments, as well as the regioselectivity observed are all in agreement with electrophilic aromatic substitution. Gold(III) 2‐pyridinecarboxylate
Thieme Chemistry Journal Awardees - Where Are They Now? Pentafluorophenyl End-Capped Polyynes as Supramolecular Building Blocks
作者:Rik Tykwinski、Jamie Kendall、Robert McDonald
DOI:10.1055/s-0029-1217706
日期:2009.8
The synthesis of pentafluorophenyl end-cappedpolyynes up to an octayne has been developed based on the use of a Fritsch-Buttenberg-Wiechell rearrangement as the key step. UV/ Vis spectroscopic analysis shows little change in the electronic nature of these structures as phenyl is formally replaced by pentafluorophenyl. The ability of pentafluorophenyl polyynes to function as supramolecular building
Transition metal-free coupling of terminal alkynes and hypervalent iodine-based alkyne-transfer reagents to access unsymmetrical 1,3-diynes
作者:J. Schörgenhumer、M. Waser
DOI:10.1039/c8ob02375a
日期:——
A variety of unsymmetrical 1,3-diynes can easily be accessed in good yields under catalyst- and transition metal-free conditions by reacting terminalalkynes with hypervalent iodine-based electrophilic alkyne-transfer reagents.
Gold‐Catalyzed Stereoselective Domino Cyclization/Alkynylation of
<i>N</i>
‐Propargylcarboxamides with Benziodoxole Reagents for the Synthesis of Alkynyloxazolines
作者:Ximei Zhao、Bing Tian、Yangyang Yang、Xiaojia Si、Florian F. Mulks、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/adsc.201900264
日期:2019.7.2
highly stereoselectivesynthesis of alkynyloxazolines via a gold‐catalyzed domino cyclization‐alkynylation cascade of N‐propargylcarboxamides with benziodoxole reagents is reported. This new protocol, which represents an attractive alternative to two step sequences based on Sonagashira couplings, offers a broad substrate scope, excellent functional group tolerance, and perfect stereoselectivity. A comparison
An Exclusively
<i>trans</i>
‐Selective Chlorocarbamoylation of Alkynes Enabled by a Palladium/Phosphaadamantane Catalyst
作者:Christine M. Le、Xiao Hou、Theresa Sperger、Franziska Schoenebeck、Mark Lautens
DOI:10.1002/anie.201507883
日期:2015.12.21
synthesized by a palladium(0)‐catalyzed intramolecular chlorocarbamoylation reaction of alkynes. A relatively underexplored class of caged phosphine ligands is uniquely suited for this transformation, enabling high levels of reactivity and exquisite transselectivity. This report entails the first transition‐metal‐catalyzed atom‐economic addition of a carbamoyl chloride across an alkyne.