160879-62-9Relevant articles and documents
Pd/BIPHEPHOS is an Efficient Catalyst for the Pd-Catalyzed S-Allylation of Thiols with High n-Selectivity
Schlatzer, Thomas,Schr?der, Hilmar,Trobe, Melanie,Lembacher-Fadum, Christian,Stangl, Simon,Schl?gl, Christoph,Weber, Hansj?rg,Breinbauer, Rolf
, p. 331 - 336 (2019/11/16)
The Pd-catalyzed S-allylation of thiols with stable allylcarbonate and allylacetate reagents offers several advantages over established reactions for the formation of thioethers. We could demonstrate that Pd/BIPHEPHOS is a catalyst system which allows the transition metal-catalyzed S-allylation of thiols with excellent n-regioselectivity. Mechanistic studies showed that this reaction is reversible under the applied reaction conditions. The excellent functional group tolerance of this transformation was demonstrated with a broad variety of thiol nucleophiles (18 examples) and allyl substrates (9 examples), and could even be applied for the late-stage diversification of cephalosporins, which might find application in the synthesis of new antibiotics. (Figure presented.).
Cobalt-Catalyzed Allylic Alkylation Enabled by Organophotoredox Catalysis
Takizawa, Koji,Sekino, Tomoyuki,Sato, Shunta,Yoshino, Tatsuhiko,Kojima, Masahiro,Matsunaga, Shigeki
supporting information, p. 9199 - 9203 (2019/06/04)
Co-catalyzed allylic substitution reactions have received little attention, arguably because of the lack of any known advantage of Co catalysis over either Rh or Ir catalysis. Described here is a general and regioselective Co-catalyzed allylic alkylation using an in situ catalyst activation by organophotoredox catalysis. This noble-metal-free catalytic system exhibits unprecedentedly high reactivities and regioselectivities for the allylation with an allyl sulfone, for the first time, representing the unique synthetic utility of the Co-catalyzed method compared to the related Rh- and Ir-catalyzed reactions.
Double Regioselective Asymmetric C-Allylation of Isoxazolinones: Iridium-Catalyzed N-Allylation Followed by an Aza-Cope Rearrangement
Rieckhoff, Stefan,Meisner, Jan,K?stner, Johannes,Frey, Wolfgang,Peters, René
supporting information, p. 1404 - 1408 (2018/01/01)
Isoxazolinones are biologically and synthetically interesting densely functionalized heterocycles, which for a long time were not accessible in enantioenriched form by asymmetric catalysis. Next to the deficit of enantioselective methods, the functionaliz
Regio- and enantioselective synthesis of chiral pyrimidine acyclic nucleosides via rhodium-catalyzed asymmetric allylation of pyrimidines
Liang, Lei,Xie, Ming-Sheng,Qin, Tao,Zhu, Man,Qu, Gui-Rong,Guo, Ha-Ming
, p. 5212 - 5215 (2017/11/06)
A direct route to branched N-allylpyrimidine analogues is herein reported via the highly regio- and enantioselective asymmetric allylation of pyrimidines with racemic allylic carbonates. With [Rh(COD)Cl]2/chiral diphosphine as the catalyst, a r
Rhodium-Catalyzed Asymmetric N?H Functionalization of Quinazolinones with Allenes and Allylic Carbonates: The First Enantioselective Formal Total Synthesis of (?)-Chaetominine
Zhou, Yirong,Breit, Bernhard
, p. 18156 - 18160 (2017/12/13)
An unprecedented asymmetric N?H functionalization of quinazolinones with allenes and allylic carbonates was successfully achieved by rhodium catalysis with the assistance of chiral bidentate diphosphine ligands. The high efficiency and practicality of this method was demonstrated by a low catalyst loading of 1 mol % as well as excellent chemo-, regio-, and enantioselectivities with broad functional group compatibility. Furthermore, this newly developed strategy was applied as key step in the first enantioselective formal total synthesis of (?)-chaetominine.
Synthesis of 1,3-Cycloalkadienes from Cycloalkenes: Unprecedented Reactivity of Oxoammonium Salts
Nagasawa, Shota,Sasano, Yusuke,Iwabuchi, Yoshiharu
, p. 13189 - 13194 (2016/10/30)
Few methods allow for the direct conversion of cycloalkenes into cycloalkadienes with high chemo- and regioselectivity. Herein, we report a convenient one-pot process for this transformation that involves the unprecedented N-preferential group transfer of N-oxoammonium salts to cycloalkenes, followed by Cope elimination, to afford cycloalkadienes at room temperature and pressure.
Sequential catalytic isomerization and allylic substitution. Conversion of racemic branched allylic carbonates to enantioenriched allylic substitution products
Shekhar, Shashank,Trantow, Brian,Leitner, Andreas,Hartwig, John F.
, p. 11770 - 11771 (2007/10/03)
A catalytic protocol for the conversion of readily accessible racemic, branched aromatic allylic esters to branched allylic amines, ethers, and alkyls has been developed. Palladium-catalyzed isomerization of branched allylic esters to terminal allylic esters, followed by sequential iridium-catalyzed allylic substitution, gave the branched allylic products in good yield with high regioisomeric and enantiomeric selectivity. Both electron-rich and electron-poor branched allylic esters gave products in >90% ee. High enantiomeric excesses were also observed for the products from the reactions of 2-thienyl acetates and dienyl carbonates. Copyright