For nucleophilic substitution, the pattern of bonds that form and break is pretty straightforward. You break C-(leaving group) and you form C-(nucleophile). A straight swap. But every once in awhile you might see a "weird" substitution reaction. If you look closely at the pattern of bonds formed and … [Read more...]
The SN2 Mechanism
Having gone through the two different types of substitution reactions, and talked about nucleophiles and electrophiles, we're finally in a position to reveal the mechanism for one of the most important reactions in organic chemistry. It's called the SN2 reaction, and it's going to be super useful … [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...]
The 4 Major Classes of Reactions in Org 1
Quiz time. Look at these reactions. Ask yourself this question for each: what bonds are broken, and what bonds are formed. Don't worry if you don't understand the reactions. That comes later. You don't need to understand the reactions to be able to answer this question. If you can do … [Read more...]
Steric Hindrance is Like a Fat Goalie
Sportswriter Todd Gallagher asked a question that every hockey fan has probably asked at one point. "Could a morbidly obese goaltender succeed in the NHL?" As he relates in "Andy Roddick Beat Me With a Frying Pan", he talked Washington Capitals owner Ted Leonisis into letting him run an … [Read more...]
What makes a good leaving group?
A leaving group is a nucleophile acting in reverse; it accepts a lone pair as the bond between it and its neighbor (usually carbon for our purposes) is broken. So what makes a good leaving group? The "happier" and more stable that lone pair is, the better a leaving group it will be. The most … [Read more...]