nucleophilic addition reaction of α, β–unsaturated carbonyl compounds |
2530
07:12 مساءً
date: 22-9-2020
|
Read More
Date: 4-9-2019
444
Date: 16-10-2020
1448
Date: 5-8-2018
880
|
eg: Two nucleophilic addition reaction could occur between methylvinyl ketone (1) and methanethiol in basic medium.
mechanism of Reaction 1:
The net reaction from 1 to 4 is the addition of two ligands to atoms 1 and 4 in 1. Hence, the reaction is called 1,4-addition, or conjugate addition, and its product (2) 1,4-adduct.
mechanism of Reaction 2:
The net reaction from 1 to 3 is the addition of two ligands to atoms 1 and 2 in 1. Hence, the reaction is called 1,2-addition, or direct addition, and the product (3) a 1,2-adduct.
The overall reaction between an α, β–unsaturated compound and a nucleophile is regioselective. Whether the dominant process is 1,4-addition or 1,2-addition depends on several factors, such as the alkene-containing reactant (the α, β–unsaturated compound), nucleophile, solvent, concentration, temperature, reaction time, and catalyst, if any, making if difficult to make a generalization. Most resonance-stabilized carbon nucleophiles, such as enolate ions and enamines overwhelmingly prefer 1,4-addition to 1,2-addition.
|
|
حمية العقل.. نظام صحي لإطالة شباب دماغك
|
|
|
|
|
إيرباص تكشف عن نموذج تجريبي من نصف طائرة ونصف هليكوبتر
|
|
|
|
بمشاركة 60 ألف طالب.. المجمع العلمي يستعدّ لإطلاق مشروع الدورات القرآنية الصيفية
|
|
صدور العدد الـ 33 من مجلة (الاستغراب) المحكمة
|
|
المجمع العلمي ينظّم ورشة تطويرية لأساتذة الدورات القرآنية في كربلاء
|
|
شعبة التوجيه الديني النسوي تختتم دورتها الثانية لتعليم مناسك الحجّ
|