Palladium(II)-Catalyzed Regioselective syn-Hydroarylation of Disubstituted Alkynes Using a Removable Directing Group
作者:Zhen Liu、Joseph Derosa、Keary M. Engle
DOI:10.1021/jacs.6b08818
日期:2016.10.5
A palladium(II)-catalyzed regioselective syn-hydroarylation reaction of homopropargyl amines has been developed, wherein selectivity is controlled by a cleavable bidentate directing group. Under the optimized reaction conditions, both dialkyl and alkylaryl alkyne substrates were found to undergo hydroarylation with high selectivity. The products of this reaction contain a 4,4-disubstituted homoallylic
已经开发了钯 (II) 催化的高炔丙基胺的区域选择性顺氢芳基化反应,其中选择性由可裂解的双齿导向基团控制。在优化的反应条件下,发现二烷基和烷芳基炔底物均以高选择性进行加氢芳基化。该反应的产物含有 4,4-二取代的高烯丙基胺基序,这在药物分子和其他生物活性化合物中很常见。
Asymmetric Hydrogenation of Furans and Benzofurans with Iridium-Pyridine-Phosphinite Catalysts
Enantioselective hydrogenation of furans and benzofurans remains a challenging task. We report the hydrogenation of 2‐ and 3‐substituted furans by using iridium catalysts that bear bicyclic pyridine–phosphinite ligands. Excellent enantioselectivities and high conversions were obtained for monosubstituted furans with a 3‐alkyl or 3‐aryl group. Furans substituted at the 2‐position and 2,4‐disubstitutedfurans proved
A new furan annelation by the palladium-catalyzed reaction of 2-alkynyl carbonates with β-keto esters is described. The reaction proceeds under mild neutral conditions and hence unstable 3-alkylidene-2,3-dihydrofurans can be prepared in this way. Similarly, reaction of 2-(1-alkynyl)oxiranes with β-keto esters gives alkylidene furans.
Taking advantage of lithium monohalocarbenoid intrinsic α-elimination in 2-MeTHF: controlled epoxide ring-opening <i>en route</i> to halohydrins
作者:Laura Ielo、Margherita Miele、Veronica Pillari、Raffaele Senatore、Salvatore Mirabile、Rosaria Gitto、Wolfgang Holzer、Andrés R. Alcántara、Vittorio Pace
DOI:10.1039/d0ob02407d
日期:——
The intrinsic degradative α-elimination of Li carbenoids somehow complicates their use in synthesis as C1-synthons. Nevertheless, we herein report how boosting such an α-elimination is a straightforward strategy for accomplishing controlled ring-opening of epoxides to furnish the corresponding β-halohydrins. Crucial for the development of the method is the use of the eco-friendly solvent 2-MeTHF, which
1,2-Dienes were prepared by the selectivehydrogenolysis of alk-2-ynylcarbonates with HCO2NH4 catalysed by Pd2(dba)3·CHCl3–PBun3(dba = dibenzylideneacetone).