Links to download Zoom Lecture Videos and PDF files
- Lecture Date: Monday, August 31, 2020
Today's was primarily introduction. We discussed the course structure, syllabus, grading scheme and my teaching philosophy. At the very end of the lecture we did a little review of where we ended last semester. Most people probably came away a feeling of apprehension at the speed of the material covered in the last 15 minutes. That was more for my brain than yours. I think you'll find the pace of the next lecture more in your comfort zone and what you can expect throughout the semester. Remember it's been three months without chemistry. It takes a little time to get the brain moving in the right direction again. We'll get there - together.
- Lecture Date: Wednesday, September 2, 2020
We launched into Chapter 9 today with a small overview of the stability of double bonds and the nomenclature of alkenes. We then took a good look at hydration reactions of alkenes. This reaction gave us the opportunity to review carbocation formation and the Hammand Postulate.
- Lecture Date: Wednesday, September 9, 2020
Today we continued our look at the addition reactions of alkenes. We explored the addition of acids, oxymercuration-demercuration, hydroboration/oxidation, and hydroboration/oxidation with 9-BBN.
- Lecture Date: Monday, September 14, 2020
We continued to cover electrophilic reactions of alkenes. We recapped and completed the hydroboration with 9-BBN. We then looked at hydrohalogenation, the free radical mechanism of hydrohalogenation with peroxide, halogenation and the formation of cyclic brominium ions, and reactions with hypobromous acid.
- Lecture Date: Wednesday, September 16, 2020
Today we concluded our look at electrophilic addition to alkenes. reagents and reactions covered today included hypochlorous acid, ozonolysis, dihydroxylation with osmium tetroxide, epoxide formation with meta-chloroperoxybenzoic acid, and catalytic hydrogenation.
- Lecture Date: Monday, September 21, 2020
After a computer software update over the weekend we ran into technical difficulties. Lecture and lab were scrapped for Monday.
- Lecture Date: Wednesday, September 23, 2020
Having recovered from Monday's technical difficulties, we are back at it again. Today we took a look at transition metal complexes and how they are used in homogeneous catalysis. We used the octet rule to model an 18 electron rule for transition metals. We then looked at a number or transition metal homogeneous catalysis reactions. We looked at catalytic hydrogenation, asymmetric catalytic hydrogenation, olefin metathesis using Grubb's catalyst, and a quick look at the Ziegler-Natta Catalyst for polymerization.
- Lecture Date: Monday, September 28, 2020
We started our look at the alkynes today. We talked a bit about the structure of the alkyne triple bond, the affects of hybridation on both bond length and acidity of the alkynyl proton. We then looked at how we can deprotonate terminal alkynes to make carbon nucleophiles to do SN2 reactions with and make new C-C bonds. From there we started to explore electrophilic reactions with alkynes. More to come......
- Lecture Date: Wednesday, September 30, 2020
Today we finished our look at alkyne reactions. Reactions covered in todays lecture include hydration, hydroboration, formation of enols and enol tautomerization, hydrogenation, and the use of poisoned catalysts in hydrogenation, and the dissolving metals reaction.
- Lecture Date: Monday, October 5, 2020
We took a dive into synthesis today. After this weekends quiz I figured we could use a little more practice at how to look at both synthetic schemes where you need to determine the reagent and at how to do retrosynthesis. Numerous examples were show in a progression of single steps, adding carbons, determining viable intermediates and finally open ended problems where the starting material is not provided but restrictions are placed on the number of carbons that can be used. More to come on synthesis as we move forward!
- Lecture Date: Wednesday, October 7, 2020
Moving forward we took a dive into free radical chemistry today. We looked at structure and stability of free radicals. It was shown that free radicals are similar in structure and stability to carbocations. We then looked at common steps in free radical reactions. Free radical initiators and inhibitors were discussed. We then looked at the mechanism and rates of halogenation for primary, secondary, and tertiary positions in alkanes.
- Lecture Date: Monday, October 12, 2020
In this lecture we finished up the free radical chapter. Today we looked at stereochemistry of free radical reactions, allylic halogenation with NBS, kinetic vs. thermodynamic products, polymerization, and some of the differences in resonance stabilization of free radicals from carbocations.
- Lecture Date: Wednesday, October 14, 2020
In this lecture we start our look at alcohols. We looked at nomenclature, physical properties, pKa, methods of deprotonation, and a review of reactions that have used or produced alcohols that we've looked at previously in other chapters. We then focused on the formation of alcohols by the reduction of carbonyl compounds. We looked at sodium borohydride an lithium aluminum hydride as reducing agents.
- Lecture Date: Monday, October 19, 2020
We continued our look at alcohols by looking into ways of synthesizing alcohols by reduction of carbonyl compounds. We looked at the differences in reactivity of sodium borohydride vs. lithium aluminumhydride. We also looked at the formation of diols from the reduction of esters. We then started to investigate the use of Grignard reaction with carbonyls to form alcohols with different substitution patterns, and the need for protecting groups to protect existing alcohols during the Grignard reaction. I'm also attaching some exam study materials to this post. I'll outline what is being posted below.
I'm posting four documents to help get ready for this exam below. The first two documents are simpeler synthesis problems and answer key. The second document is a common patterns for synthesis. This document is really dense, but it has super good problems in it. I demonstrate usage of a skill followed by 4 or 5 problems that use that skill along with an answer key for each. And finally I have a study guide for the first exam that has many different problem types that you will see. So that's it, you've got resources.
- Lecture Date: Wednesday, October 21, 2020
Today we finished what I think is chapter 12 by looking at the rest of the alcohol protecting groups. We reviewed the silyl ethers (TMS, TBDMS, TIPS), and introduced acetal type protecting groups (MOM, THP ), ester type protecting group (Bz), and the benzyl type (Bn). Next week we'll hit chapter 13 where we will look at oxidation reactions and other reactions of hydroxyl groups.
- Lecture Date: Monday, October 26, 2020
We closed out this section with a look at the reactions of alcohols. In this chapter we ask what can we do with alcohols? We looked at many types of reactions, some familiar and others new, of ways of reacting alcohols to make other functional groups. The main reactions that we covered are SN1,SN2, E1, E2, conversion to halogens with thionyl chloride or phosphorus tribromide, conversion to tosylates with tosylchloride, and then oxidation to aldehydes, ketones and carboxylic acids.
- Lecture Date: Wednesday, October 28, 2020
Last lecture before the exam. Today was a big review day. We focused on organizing all the information that we've covered. We built star charts for the alkenes, alkynes and alcohols. We took a look at reactions that form alcohols of different substitution patterns, and reactions of alcohols to make different functional groups.