58083-55-9Relevant academic research and scientific papers
Br?nsted Acid Catalyzed Dearomatization by Intramolecular Hydroalkoxylation/Claisen Rearrangement: Diastereo- and Enantioselective Synthesis of Spirolactams
Chen, Peng-Fei,Wang, Binju,Wu, Peng,Ye, Long-Wu,Zhou, Bo
, p. 27164 - 27170 (2021/11/22)
Described herein is a novel Br?nsted acid catalyzed intramolecular hydroalkoxylation/Claisen rearrangement, allowing the practical and atom-economic synthesis of a range of valuable spirolactams from readily available ynamides in generally good to excellent yields with excellent diastereoselectivities and broad substrate scope. Importantly, an unexpected dearomatization of nonactivated arenes and heteroaromatic compounds is involved in this tandem sequence. Moreover, an asymmetric version of this tandem cyclization was also achieved by efficient kinetic resolution by chiral phosphoric acid catalysis. In addition, the [3,3]-rearrangement is shown to be kinetically preferred over the related [1,3]-rearrangement by theoretical calculations.
Ynamide Smiles Rearrangement Triggered by Visible-Light-Mediated Regioselective Ketyl-Ynamide Coupling: Rapid Access to Functionalized Indoles and Isoquinolines
Chen, Yang-Bo,Sun, Zhou,Wang, Ze-Shu,Ye, Long-Wu,Zhang, Hao-Wen,Zhu, Chunyin
supporting information, p. 3636 - 3644 (2020/03/06)
In the past decades, significant advances have been made on radical Smiles rearrangement. However, the eventually formed radical intermediates in these reactions are limited to the amidyl radical, except for the few examples initiated by a N-centered radical. Here, a novel and practical radical Smiles rearrangement triggered by photoredox-catalyzed regioselective ketyl-ynamide coupling is reported, which represents the first radical Smiles rearrangement of ynamides. This method enables facile access to a variety of valuable 2-benzhydrylindoles with broad substrate scope in generally good yields under mild reaction conditions. In addition, this chemistry can also be extended to the divergent synthesis of versatile 3-benzhydrylisoquinolines through a similar ketyl-ynamide coupling and radical Smiles rearrangement, followed by dehydrogenative oxidation. Moreover, such an ynamide Smiles rearrangement initiated by intermolecular photoredox catalysis via addition of external radical sources is also achieved. By control experiments, the reaction was shown to proceed via key ketyl radical and α-imino carbon radical intermediates.
Palladium-Catalyzed Direct C-H Carbonylation of Free Primary Benzylamines: A Synthesis of Benzolactams
Zhang, Chunhui,Ding, Yongzheng,Gao, Yuzhen,Li, Shangda,Li, Gang
supporting information, p. 2595 - 2598 (2018/05/22)
A protocol for palladium-catalyzed C-H carbonylation of readily available free primary benzylamines using NH2 as the chelating group under an atmospheric pressure of CO has been achieved, providing a general, atom- and step-economic approach to
Traceless Directing Group Assisted Cobalt-Catalyzed C?H Carbonylation of Benzylamines
Ling, Fei,Ai, Chongren,Lv, Yaping,Zhong, Weihui
supporting information, p. 3707 - 3712 (2017/10/07)
The first example of cobalt-catalyzed C(sp2)?H carbonylation of benzylamines using a traceless directing group is reported, which was successfully applied to the synthesis of N?unprotected iso-indolinones through direct C?H/N?H bonds activation. This protocol tolerates a variety of functional groups and provides a facile and efficient method for the formal synthesis of (+)-garenoxacin. (Figure presented.).
A simple and convenient one-pot synthesis of substituted isoindolin-1-ones via lithiation, substitution and cyclization of N'-benzyl-N,N-dimethylureas
Smith, Keith,El-Hiti, Gamal A.,Hegazy, Amany S.,Kariuki, Benson
supporting information; experimental part, p. 1219 - 1227 (2011/11/05)
Lithiation of N'-benzyl-N,N-dimethylurea and its substituted derivatives with t-BuLi (3.3 equiv) in anhydrous THF at 0 °C followed by reaction with various electrophiles afforded a range of 3-substituted isoindolin-1-ones in high yields.
Convenient access to isoindolinones via carbamoyl radical cyclization. Synthesis of cichorine and 4-hydroxyisoindolin-1-one natural products
López-Valdez, Germán,Olguín-Uribe, Simón,Millan-Ortíz, Alejandra,Gamez-Monta?o, Rocio,Miranda, Luis D.
experimental part, p. 2693 - 2701 (2011/04/24)
An efficient and convenient access to 2-tert-butylisoindolin-1-ones via an oxidative radical cyclization process from stable carbamoylxanthates, derived from secondary tert-butylamines, is described. The proposed mechanism for this transformation involves, the generation of a carbamoyl radical, its cyclization to the aromatic system, and the dilauroyl peroxide (DLP) mediated rearomatization to generate the isoindolinone ring system. Additionally, the syntheses of cichorine and 4-hydroxyisoindolin-1-one natural products were carried out to underscore the synthetic potential of this xanthate-based carbamoyl radical-oxidative cyclization.
Carbamoyl radicals from carbamoylxanthates: a facile entry into isoindolin-1-ones
López-Valdez, Germán,Olguín-Uribe, Simón,Miranda, Luis D.
, p. 8285 - 8289 (2008/03/30)
It has been found that carbamoylxanthates derived from secondary t-butyl amines are stable compounds which function as efficient sources of carbamoyl radicals. The carbamoylxanthates derived from t-butylbenzylamines can be efficiently transformed into 2-t
