backside attack

My new favorite, the Eschweiler–Clarke reaction!

The Eschweiler–Clarke reaction (also called the Eschweiler–Clarke methylation) is a chemical reaction whereby a primary (or secondary) amine is methylated using excess formic acid and formaldehyde. Reductive amination reactions such as this one will not produce quaternary ammonium salts, but instead will stop at the tertiary amine stage. It is named for the German chemist Wilhelm Eschweiler (1860–1936) and the British chemist Hans Thacher Clarke (1887-1972).

The mechanism of the reaction is really simple, first methylation of the amine begins with imine formation with formaldehyde. The formic acid acts as a source of hydride and reduces the imine to a secondary amine. The driving force is the formation of the gas carbon dioxide. Formation of the tertiary amine is similar, but slower due to the difficulties in iminium ion formation.

Columbia researchers recently published work using quantum mechanics and a supercomputer to reveal how the world’s strongest, thinnest materials break. The study was inspired by previous work on graphene and found that several other monolayer materials have a very similar failure mechanism despite having extremely different electronic properties.

Their results contradict previous explanations of why graphene breaks based on a well-known concept in physics called a “Peierls instability”.

Let’s talk about one of my favorite reactions: the benzoin condensation! This reaction is formally a disproportionation reaction: the carbonyl carbon goes from a +1 state in the starting material to 0 and +2 in the hydroxyl and new carbonyl carbon, respectively.

At first glance, this reaction appears to happen by simple nucleophilic addition to one of the carbonyls. However, this is not the case at all; benzaldehyde is not readily deprotonated, with a pKa close to 15. In fact, because of the carbon-oxygen double bond, that carbon is highly electrophilic! How does this reaction proceed? The answer lies in the cyanide catalyst. Let’s examine the mechanism more closely to figure out what exactly goes on…

The brominated Wilkinson catalyst: RhBr(PPh3)3.

literally the only reason i can memorize the TCA cycle

This pretty yellowish stuff is some highly toxic and hazardous organomercuric reagent what was made in situ from some mercury(II)-acetate and an alkene.