Last Minute Lecture

SN1 vs SN2 Substitution Reactions Explained — Mechanisms, Factors, and Stereochemistry | Chapter 9 of Klein Organic Chemistry as a Second Language Substitution reactions are among the most important and most tested reactions in introductory organic chemistry. In Chapter 9 of Organic Chemistry as a Second Language: First Semester Topics by David Klein, students learn how to distinguish between SN1 and SN2 mechanisms and predict which pathway will dominate under a given set of conditions. This chapter synthesizes everything learned so far—mechanisms, stereochemistry, carbocations, nucleophiles, and solvents—into a practical decision-making framework that applies across the rest of the course. 🎥 Watch the video above for a clear, step-by-step breakdown of SN1 and SN2 substitution reactions and how to confidently predict reaction outcomes. What Are Substitution Reactions? In a substitution reaction, one group attached to a carbon atom—the leaving group—is replaced by anoth...

Organic Reaction Mechanisms Explained — Arrow Pushing, Nucleophiles, and Carbocation Rearrangements | Chapter 8 of Klein Organic Chemistry as a Second Language Reaction mechanisms are the logic engine of organic chemistry. In Chapter 8 of Organic Chemistry as a Second Language: First Semester Topics by David Klein, students learn how and why reactions occur by following the movement of electrons step by step. Rather than memorizing reactions as isolated facts, this chapter teaches mechanisms as unified problem-solving tools that make organic chemistry more intuitive, predictable, and easier to retain. 🎥 Watch the video above for a guided walkthrough of curved-arrow notation, reaction intermediates, and the core patterns that appear throughout organic chemistry. What Is a Reaction Mechanism? A reaction mechanism is a step-by-step depiction of how electrons move during a chemical reaction. Unlike resonance structures, which conceptually represent electron delocalization,...