Selectivity in the electrochemical deprotection of cinnamyl groups from oxygen and nitrogen functionalities: carbonates versus carbamates
摘要:
Several cinnamyloxy carbamates and carbonates were subjected to electrochemical reduction, and the reductive fate of the cinnamyl group was investigated. Complete selectivity was observed in the removal of the cinnamyl group from oxygen versus nitrogen. (c) 2005 Elsevier Ltd. All rights reserved.
Synthesis of allyl selenides by palladium-catalyzed decarboxylative coupling
作者:Shelli R. Waetzig、Jon A. Tunge
DOI:10.1039/b806949b
日期:——
This communication details the Pd-catalyzed decarboxylation of selenocarbonates; use of a chiral nonracemic catalyst affords enantioenriched allyl selenides which undergo stereospecific [2,3]-sigmatropicrearrangements to form enantioenriched allylic amines and chlorides.
Pd-Catalyzed Rearrangement of <i>N</i>-Alloc-<i>N</i>-allyl Ynamides <i>via</i> Auto-Tandem Catalysis: Evidence for Reversible C–N Activation and Pd(0)-Accelerated Ketenimine Aza-Claisen Rearrangement
作者:Juliana R. Alexander、Veronika I. Shchepetkina、Ksenia S. Stankevich、Rory J. Benedict、Samuel P. Bernhard、Reagan J. Dreiling、Matthew J. Cook
DOI:10.1021/acs.orglett.0c04078
日期:2021.1.15
An auto-tandem catalytic double allylic rearrangement of N-alloc-N-allyl ynamides was developed. This reaction proceeds through two separate and distinct catalytic cycles with both decarboxylative Pd−π-allyl and Pd(0)-promoted aza-Claisen rearrangements occurring. A detailed mechanistic study supported by computations highlights these two separate mechanisms. Previously unreported reversible C–N ionization
Enantioselective Intramolecular Iridium-Catalyzed Cyclopropanation of α-Carbonyl Sulfoxonium Ylides
作者:Lucas Vidal、Pan-Pan Chen、Eva Nicolas、Andrew Hackett、Craig M. Robertson、Kendall N. Houk、Christophe Aïssa
DOI:10.1021/acs.orglett.2c03396
日期:2022.11.25
Enantioselective cyclopropanation of α-carbonyl sulfoxonium ylides (SY) has so far been limited to addition/ring closure reactions on electron-poor olefins. Herein, we report the iridium-catalyzed intramolecular cyclopropanation of SY in the presence of a chiral diene in up to 96% yield and 98% enantioselectivity. Moreover, density functional theory calculations suggest that the re face of the olefin
迄今为止,α-羰基亚砜 (SY) 的对映选择性环丙烷化仅限于缺电子烯烃的加成/闭环反应。在此,我们报道了在手性二烯存在下铱催化的 SY 分子内环丙烷化反应,收率高达 96%,对映选择性高达 98%。此外,密度泛函理论计算表明,烯烃的表面优选在与烯烃的几何结构无关的异步协同步骤中攻击铱卡宾中间体。
Photocatalytic Intramolecular Alkene Hydroamination of <i>N</i>-Alkoxy Ureas: An Approach to Imidazolinones
in good yields by intramolecular hydroamination of N-alkoxy ureas in the presence of an organic photocatalyst and an inorganic base. In this reaction, the N-alkoxy urea anion generated by deprotonation undergoes photocatalyzed single-electron-transfer oxidation to generate the correspondingradical, which cyclizes to afford the imidazolinone ring. This new protocol grants access to an array of complex
Selectivity in the electrochemical deprotection of cinnamyl groups from oxygen and nitrogen functionalities: carbonates versus carbamates
作者:Petr Cankař、Diane Dubas、Scott C. Banfield、M’hamed Chahma、Tomas Hudlicky
DOI:10.1016/j.tetlet.2005.08.020
日期:2005.10
Several cinnamyloxy carbamates and carbonates were subjected to electrochemical reduction, and the reductive fate of the cinnamyl group was investigated. Complete selectivity was observed in the removal of the cinnamyl group from oxygen versus nitrogen. (c) 2005 Elsevier Ltd. All rights reserved.