Functional rearrangement of 3-Cl or 3,3-diCl-γ-lactams bearing a secondary 1-chloroalkyl substituent at C-4
摘要:
The study of the reaction with MeONa/MeOH of chlorinated gamma-lactams. prepared from the atom transfer radical cyclization of N-allyl-alpha-perchloroamides, has been extended to the case of substiates carrying an exo halogen atom on a branched carbon Only with secondary exo C-Cl groups, that are not located on a fused ring, does the functional rearrangement follow the typical transformation route, Which With trichloro-lactams can proceed further to give 4-alkylidene derivatives From a practical point of view, the outcome of the reaction with di- or trichloio N-cinnamylamides is synthetically valuable, affording the 5-methoxy-IH-pyrrol-2(5H)-one or 3-benzylidenepyrrlidine-2.5-dione. respectively. in good to excellent yield (C) 2009 Elsevier Ltd All rights reserved
Exocyclic Olefinic Maleimides: Synthesis and Application for Stable and Thiol-Selective Bioconjugation
作者:Dimpy Kalia、Pushpa V. Malekar、Manikandan Parthasarathy
DOI:10.1002/anie.201508118
日期:2016.1.22
reactions between biological thiols and endocyclic olefinicmaleimides are extensively used for site‐specific bioconjugation. The resulting thio‐succinimidyl linkages, however, lack stability because of their susceptibility to thiol exchange. Reported herein is that in contrast to their endocyclic counterparts, exocyclicolefinicmaleimides form highly stable thio‐Michael adducts which resist thiol exchange
(E)-3-arylidene-4-diazopyrrolidine-2,5-diones in the Rh(II)-catalyzed condensation with nitriles to form 1,3-oxazoles led to an unexpected outcome. The nitrilium ylide species thought to form on Rh(II)-catalyzed decomposition of diazo compounds underwent a cyclization onto the nearby arylidene moiety followed by 1,5-hydride shift. This led to the formation of a 2-benzazepine core which has special significance
尝试在 Rh( II ) 催化的与腈的缩合反应中使用 ( E )-3-arylidene-4-diazopyrrolidine-2,5-diones以形成 1,3-oxazoles 导致了意想不到的结果。被认为在 Rh( II ) 催化的重氮化合物分解上形成的腈叶立德物种经历了环化到附近的亚芳基部分上,然后发生 1,5-氢化物位移。这导致了 2-苯并氮杂核心的形成,该核心对药物发现具有特殊意义,可以被认为是一种特殊的支架。
A One-pot Green Synthesis of Alkylidenesuccinimides
A mild and facile Wittig reaction between N‐substituted maleimides and aldehydes has been developed. Various synthetically valuable alkylidenesuccinimides were obtained from this one‐pot reaction in high yields (up to 99%). The product was obtained by simple filtration and no extra purification was necessary. Ethanol, an environment‐benign solvent, was found to be a suitable reaction medium.
DBU-catalyzed [3 + 2] cycloaddition and Michael addition reactions of 3-benzylidene succinimides with 3-ylidene oxindoles and chalcones
作者:Piyush Tehri、Rama Krishna Peddinti
DOI:10.1039/c9ob00385a
日期:——
A metal-free DBU catalyzed protocol has been developed for the regioselective [3 + 2] cycloaddition reactions of 3-benzylidene succinimides with 3-ylidene oxindoles to furnish spirooxindole derivatives. The 3-benzylidene succinimides underwent Michaeladdition with chalcones to provide benzylidene succinimide-tethered propanones. All the reactions proceeded under mild conditions and the products were
insertion into a tetrahydrofuran molecule. This competing process gave compoundsbased on the 3-(tetrahydrofur-2-yl)pyrrolidine scaffold, which are also relevant from the medicinal chemistry standpoint. These findings enrich the available arsenal of metal-catalyzed spirocyclization methods based on the use of cyclic diazocompounds.