Synthesis of amino-diamondoid pharmacophores <i>via</i> photocatalytic C–H aminoalkylation
作者:William K. Weigel、Hoang T. Dang、Hai-Bin Yang、David B. C. Martin
DOI:10.1039/d0cc02804e
日期:——
direct C–H aminoalkylation reaction using two light-activated H-atom transfer catalyst systems that enable the introduction of protected amines to native adamantane scaffolds with C–C bond formation. The scope of adamantane and imine reaction partners is broad and deprotection provides versatile amine and amino acid building blocks. Using readily available chiral imines, the enantioselective synthesis
我们报告了使用两种光活化 H 原子转移催化剂系统的直接 C-H 氨基烷基化反应,该反应能够将受保护的胺引入具有 C-C 键形成的天然金刚烷支架。金刚烷和亚胺反应伙伴的范围很广,去保护提供了通用的胺和氨基酸构建块。使用容易获得的手性亚胺,还描述了沙格列汀核心和金刚乙胺衍生物的对映选择性合成。
Rh-Catalyzed Enantioselective Allylation of <i>N</i>-Tosyl- and <i>N</i>-Nosylaldimines: Total Synthesis of (−)-Crispine A
The unprecedented development of asymmetric Rh-catalyzed 1,2-allylation of N-Ts- and N-Ns-aldimines is achieved. This protocol utilizes potassium allyltrifluoroborates and various aldimines to generate enantioenriched homoallylic amines in the presence of 3.0 mol % of Rh(I)/L1b catalyst with up to 90% yield, 98% ee (R = H), and 10:1 diastereoselectivity (R = Me or Ph), yielding the same major diastereomer
Multicomponent Synthesis of Substituted and Fused-Ring Imidazoles via Phospha-münchnone Cycloaddition
作者:Sara Aly、Mikhail Romashko、Bruce A. Arndtsen
DOI:10.1021/jo5028936
日期:2015.3.6
A new, one-pot synthesis of imidazoles from imines, acid chlorides, and N-nosyl imines or tethered nitriles is reported. The reaction is mediated by the phosphonite PPh(catechyl) and proceeds via regioselective cycloaddition with an in situ-generated phospha-münchnone 1,3-dipole. This provides an efficient route to construct both highly substituted and polycyclic imidazoles directly from available
作者:Sobia Tabassum、Oksana Sereda、Peddiahgari Vasu Govardhana Reddy、René Wilhelm
DOI:10.1039/b908899g
日期:——
KHMDS and KOtBu are well established as strong, hindered, non-nucleophilic Brønsted bases. However, in the present work these bases are applied as highly active Lewis base catalysts for the formal [2+2] cycloaddition of ketenes with aldehydes and imines.
Hydroxyproline-Derived Pseudoenantiomeric [2.2.1] Bicyclic Phosphines: Asymmetric Synthesis of (+)- and (−)-Pyrrolines
作者:Christopher E. Henry、Qihai Xu、Yi Chiao Fan、Tioga J. Martin、Lee Belding、Travis Dudding、Ohyun Kwon
DOI:10.1021/ja505592h
日期:2014.8.27
We have prepared two new diastereoisomeric 2-aza-5-phosphabicyclo[2.2.1]heptanes from naturally occurring trans-4-hydroxy-l-proline in six chemical operations. These syntheses are concise and highly efficient, with straightforward purification. When we used these chiral phosphines as catalysts for reactions of γ-substituted allenoates with imines, we obtained enantiomerically enriched pyrrolines in