Organic Chemistry II - Aromatic Reactions and Carbonyls!

This lecture covers type ii carbonyls, aldehydes and ketones, undergoing nucleophilic addition to form a tetrahedral intermediate, with strong nucleophiles driving and weak or moderate ones allowing reversibility.

The lecture explains how a nucleophile attacks a carbonyl of an aldehyde to form a tetrahedral intermediate, and introduces turning carbon into a nucleophile with a metal for Grignard reaction.

Discover how to form Grignard reagents from alkyl halides using magnesium in ether, and harness them to create new carbon–carbon bonds in reactions.

Explore making Grignard reagents from sp2-hybridized carbons, showing magnesium inserts between carbon and bromine and the nucleophilic carbon attacks an alkyl halide to form a new C–C bond.

Explore Grignard reactions with type i carbonyls, including esters; form tetrahedral intermediates and ketone or alcohol products. Excess Grignard biases the reaction toward alcohol by converting ketones.

learn how hydrides attack type two carbonyls to form tetrahedral intermediates, then are quenched to give alcohols, using sodium borohydride as a safer hydride source.

Explore how weak to moderate nucleophiles, especially amines, react with type II carbonyls under catalytic acid to form imines via a reversible addition–dehydration pathway, with water as the leaving group.

Examine how alcohols add to type II carbonyls to form hemi-ketals, and, with excess alcohol, ketals, guided by equilibria, acid protonation, and water loss.

Explore how alcohols react with aldehydes to form hemiacetals and acetals, predict products for more complex carbonyls, and distinguish acetyl from acetone while naming the derived groups.

Investigate selective reductions of ketones versus esters using sodium borohydride and lithium aluminum hydride, and discuss why each reagent behaves differently.

This lecture covers the aldol reaction: enolates attack type two carbonyls to form an alkoxide that protonates to an alcohol, with mixed aldol products and addition behavior.

Discover the mixed aldol reaction, yielding four distinct products from two aldehydes, and practice dehydration to forge a new alpha–beta double bond.

Leverage bulky bases like lda to fully form the enolate, shifting equilibrium to the nucleophile and avoiding multiple aldol products. This yields a cleaner one-to-one reaction with easier purification.

Assess aromatic criteria by confirming planarity and sp2 hybridized carbons, then count lone pairs that participate in resonance to yield an odd total of electron pairs.

Assess aromaticity by confirming a cyclic, uninterrupted ring of pi electrons, planarity, and an odd number of electron pairs, including delocalization through lone pairs and bonds.

Explore how weak electron-withdrawing groups like halogens still direct electrophilic aromatic substitution to ortho and para positions, not meta, due to inductive withdrawal overpowering resonance.

Explore how steric blockade from bulky groups redirects electrophilic aromatic substitution from ortho toward para, reducing ortho selectivity from about 66% to ~50/50.

Explore arene diazonium salts formed from primary amines at 0 °C, and use them in nitrile formation via copper cyanide and in azo dye synthesis through electrophilic substitution.