Skip to main content

Pericyclic Reactions vs Polar Reactions. Use of Heterocycles as Electrophiles. Microwave Irradiation | Chapter 5 | Theory and Applications of Chemistry Vol. 2

Considering the possibility of analyzing polar cycloaddition reactions, in this work we studied a series Diels-Alder reaction using different heterocycles derivatives acting as electrophiles joint to dienes of different nucleophilicity, analyzing the effect of the microwave irradiation in these processes. For this, two reaction conditions have been worked: toluene as solvent and solvent free. The last one presents the better yield in shorter time of reaction. Using microwave heating the aromatic cycloadducts are clearly predominant. The reactions that will be discussed could be considered of the pericyclic type, however  taken  account  the  effect  of  the  solvent  on  them,  they  could  also  be  considered  polar. Consequently, it would be in the presence of a borderline situation. The methodology explored could be used in commercial form. However, it would be necessary to have the required equipment for this purpose. From a  formal  point  of  view  the  reactions that  are  discussed  could  be considered  polar. Considering the dynamics of the reactions, in only one case it was possible to verify the presence of an intermediate state, while in the rest of them there was observed the presence of concerted and markedly asynchronic reactions. For all these reasons in this work we try to discuss the scope of this reactive model and its location in the panorama of the ways in which it proceeds according to the reaction mechanism. That to say if for this kind of process, the concept of pseudo-pericyclic reaction is applicable. The  important  solvent  effect  observed  in  these persuades us to consider these processes as PD-A reactions in which an electrophile reacts with a nucleophile. On the other hand, when microwave irradiation was used, the best results were obtained in free solvent conditions. We confirm this approach using theoretical calculations based on Density Functional Theory (DFT).

Author(s) Details

Maria N. Kneeteman
IQAL (UNL-CONICET), Laboratorio Fester –QUIMICA ORGANICA (FIQ), Universidad Nacional del Litoral, Santiago del Estero 2829, 3000 Santa Fe, Argentina.

Read full article: http://bp.bookpi.org/index.php/bpi/catalog/view/49/266/415-1
View Volume: https://doi.org/10.9734/bpi/tac/v2
Labels:

Comments

Post a Comment

Popular posts from this blog

A Prospective Study about Safety and Efficacy of Perioperative Lidocaine Infusion | Chapter 09 | New Horizons in Medicine and Medical Research Vol. 8

 Opioids cause clinically significant side effects such as respiratory depression, immunosuppression, muscle rigidity, negative inotropism, nausea, vomiting, hyperalgesia, urine retention, postoperative ileus, and drowsiness. Perioperative opioids are a major contributor to the United States' and other countries' opioid epidemics. Non-opioid analgesics, particularly lidocaine, are becoming more common for perioperative use as a result of this. A total of 185 adult patients were randomly assigned to one of two groups: control group I (105 patients) [fentanyl group] or group ii (80 patients) [opioid-free anaesthesia group]. Lidocaine 1.5 mg/kg bolus followed by 1.5 mg/kg/h infusion intraoperatively, and 1.5-2 mg/kg/h infusion for 2-8 hours postoperatively were given to patients in both groups at anaesthetic induction. Intraoperatively, both groups received analgesic adjuvants such as diclofenac 75 mg, paracetamol 1 gm, and mgso4 30-50 mg/kg. If the mean arterial pressure (map)
Post a Comment
Read more

A Brief Study of Middleware Technologies: Programming Applications and Management Systems | Chapter 15 | Novel Research Aspects in Mathematical and Computer Science Vol. 1

  Many platforms, services, applications, hardware, and operating systems are connected through the middleware layer. Because the middleware layer abstracts much low-level complexity and makes applications and software systems portable, it allows disparate systems to interface and function together in harmony. Middleware technologies enable software engineers to swiftly construct software systems and applications, allowing developers to focus on more important tasks. This chapter examines several types of middleware systems and discusses middleware capabilities, middleware operation, middleware's function in cloud-based systems, and the best middleware platforms to use. Middleware systems are widely utilised and can be found in practically any software system or application. Middleware programmes provide as a link between many sorts of systems and protocols. They serve as a mechanism for various systems. To successfully exchange information, it runs on a variety of operating system
Post a Comment
Read more

Patients’ Perspective of Acute Post-operative Pain Management: A Multicentre Survey of Tertiary Hospitals in Maharashtra, India | Chapter 08 | New Horizons in Medicine and Medical Research Vol. 8

 When postoperative pain is adequately controlled, patients' satisfaction and patient-related outcomes (PROs) increase. Understanding the patients' perspective is crucial since it supports in the formulation of improvement strategies. Because wrong attitudes and assumptions might block pain alleviation, patients' attitudes and beliefs are critical. As a result, a multicenter study of patients' attitudes, beliefs, experiences, and satisfaction levels with acute postoperative pain management was done in Maharashtra's tertiary hospitals. In addition, the responses were examined to evaluate if the Acute Pain Service (APS) resulted in improved patient outcomes and satisfaction. A 13-item questionnaire adapted from previous studies was used to capture patients' experiences with postoperative pain treatment. The responses of 179 patients are included in the study. The findings revealed that 91.6 percent of patients experienced postoperative pain, with 75.5 percent
Post a Comment
Read more