Scale-Up of the Green Synthesis of Azacycloalkanes and Isoindolines under Microwave Irradiation
摘要:
A green approach to N-heterocyclization reactions ranging in scale from 20 mmol to 1 mol performed under microwave irradiation in open vessels has been investigated. By using water as the solvent and no transition metal catalysts, N-heterocycles are formed in a fraction of the time needed for conventional synthesis of these compounds. The obtained yields indicate that reactions can be performed at atmospheric pressure using the same reaction conditions as the corresponding sealed-vessel reactions. Single-mode and multimode microwave cavities have been used for open-vessel synthesis without changing reaction times producing similar yields.
Iron‐Catalysed Switchable Synthesis of Pyrrolidines
<i>vs</i>
Pyrrolidinones by Reductive Amination of Levulinic Acid Derivatives
<i>via</i>
Hydrosilylation
作者:Duo Wei、Chakkrit Netkaew、Christophe Darcel
DOI:10.1002/adsc.201801656
日期:2019.4.16
A selective production of pyrrolidines vs pyrrolidinones via hydrosilylation of levulinic acid and levulinates by switching of the iron complex catalyst is presented herein. The reactions proceeded efficiently with various anilines and alkylamines under both visible light irradiation and thermal conditions with 43 examples in isolated yields up to 93%. Noticeably, under similar conditions, cyclic amines
Visible-Light Induced Isoindoles Formation To Trigger Intermolecular Diels–Alder Reactions in the Presence of Air
作者:Chao Lin、Le Zhen、Yong Cheng、Hong-Jin Du、Hui Zhao、Xiaoan Wen、Ling-Yi Kong、Qing-Long Xu、Hongbin Sun
DOI:10.1021/acs.orglett.5b01078
日期:2015.6.5
Visible-light induced isoindole formation triggered an intermolecular Diels-Alder reaction with dienophiles such as acetylenedicarboxylate and maleimides in the presence of air. The reaction resulted in excellent diastereoselctivity and high yields under mild reaction conditions. This protocol provides an atom-economical, transition-metal-free (TM-free) and straightforward approach to structurally diverse bridged-ring heterocycles from easily accessible molecules.