Oxidation and reduction

Why are transition metals good oxidising agents?

High oxidation states

What can p-block elements in high oxidation states do?

Selectively oxidise alcohols to aldehydes

Why are Per-oxy reagents really good?

Container electrophilic O

Chemos3lective for double bonds

What does jones oxidation involve?

CrO3 and H2SO4

What is Jones reagent soluble in?

Water

What Cr source dissolves in organic solvents?

PCC

What is the downside of PCC?

Cr is highly toxic and rarely used in scale

What’s good about ruthenium?

Much less toxic

What is the most important reagent in part b of oxidation of simple alcohol?

MnO2

What does MnO2 do?

Selectively oxidises allylic and benzylic alcohols

What does nitric acid do?

Oxidises simple alcohols to carboxylic acids

What are the properties of DMP?

+5

Hypervalent

Can oxidises very sensitive alcohols to carbonyls

Why is DMP special?

Only oxidant to not cause double bond isomerisation

What does swern oxidation involve?

COCl2, DMSO/ NET3

What is oxidised in swern oxidation?

Alcohols to aldehyde and ketones

What does ozone do?

Oxidises alkene to alcohols, aldehyde and carboxylic acids

What is the trend in epoxidation reactivity?

Number of methyl groups increases rate of reaction increases

What reagent leads to epoxidation?

m-CPBA

Names reducing agents?

Hydrogen

Hydrates of B and Al

S and Mg

Why is H2 an ideal reducing agent but isn’t used?

Not reactive enough on its own

Must pair with group 10 metals

What is Na and Mg involved in?

Dissolving metal reductions

What type of mechanism does H2 use?

Catalytic hydrogenation

What can alkene be reduced in presence of?

Pd/C

What catalyst is needed to convert alkynes to alkene?

Pd/CaCO3

What solvent is used in reduction of alkynes to alkenes?

Pb(OAc)2

What catalyst and conditions is used to reduce benzene to cyclohexane?

Ni

100atm, 50°C

What are the steps in making amines?

1. Nitro reduction

2. Reductive amination

What catalyst is used to form amines?

Pd or Pt

What solvent is used in formation of amine?

EtOH (+AcOH)

What does borane do that borohydrides don’t?

Reduce carboxylic acids

Why is borane reactive?

Stems from willingness to accept electrons into an empty p orbital

What is used to reduce amides to amines?

BH3

What is used to reduce esters to alcohols

LiAlH4

What does DIBAL do?

Allow selective reduction of esters to aldehydes

What is used to reduce amides to amines?

LiAlH4

How does dissolving metal reduction work?

Reacting Na with liquid ammonia in alcohol solvent to form solvated electrons