The last two posts have been about a pretty amazing new concept. Not only can lone pairs act as nucleophiles…. but π bonds can too! Alkenes are a lot more exciting than they're often given credit for. That means that given a sufficiently frisky electrophile, they can donate their pair of … [Read more...]
Nucleophilicity vs. Basicity
Following up on Nucleophiles and Electrophiles, here's a common question students have about nucleophilicity: What's the difference between nucleophilicity and basicity? Great, great question. First of all, remember that basicity is a subset of nucleophilicity. All nucleophiles are Lewis … [Read more...]
Nucleophiles and Electrophiles
All through the series on understanding where electrons are, and how they flow, we've been talking about how the basis of chemistry is that opposite charges attract and like charges repel, and that in reactions, electrons flow from "electron rich" areas to "electron poor" areas. Today, we'll … [Read more...]
Acid Base Reactions: What’s the Point?
One thing has been missing from our discussion of acid-base reactions. Who cares? What does it matter that we understand acid base reactions? Why is it important? Today, I hope to show that it matters a lot, not only for its own sake, but for topics that concern the rest of the … [Read more...]
Reaction Friday: Friedel Crafts Acylation
Today's Reaction Friday is about the Friedel Crafts acylation of benzene and other aromatics, an important example of electrophilic aromatic substitution. One thing I forgot to say at the bottom is that there's several different ways of showing how the acyl halide is activated by Lewis acid - … [Read more...]
Introduction to Nucleophilic Substitution Reactions
Following up on the 4 most important patters of reactions in Org 1, and introduction to acid-base reactions, here's the second major pattern. It's called nucleophilic substitution. I won't go into nucleophiles and electrophiles in this post. The point is actually not to understand what's going on … [Read more...]
Partial Charges Give Clues About Electron Flow
There's a hidden layer of detail beneath chemical structures that students new to organic chemistry often miss. I'm talking about partial charges. Although each of these bonds appears to be covalent, the electronegativity of each atom determines how "greedy" it is for electrons - and this … [Read more...]
Common Blind Spot: Intramolecular Reactions
So I bought a belt today (pleather, 75 cents at the Goodwill). and decided to show it off. This is me putting it together. This is what it looks like now: At this point you're probably saying WTF: that's not what a belt is supposed to look like when you put it together. That's because … [Read more...]