Webb Industrial processes

Question 1

what is hydroformylation?

Answer 1

turns a propene into an aldehyde

Question 2

What metal catalysts can be used for hydroformylation

Answer 2

Co or Rh

Question 3

What are the steps of a hydroformylation

Answer 3

alkene coordination –> migratory insertion x2 –> oxidative addition of H2 –> reductive elimination

Question 4

What is the Shell process?

Answer 4

a type of hydroformylation that uses a v. large HCoCO3 complex with a PR3 ligand. (lowers the pressure compared to the Exxon process but temperature must be increased to account for slower reaction time) Increases hydrogenation activity

Question 5

why would you use a phosphine ligand over a phosphite ligand?

Answer 5

PR sigma* accepts e density from metal.
Whereas POR lowers the energy of the sigma* - better pi acceptor –> withdraws energy from M-C so increases C=O bond strength

Question 6

example of a process where an aqueous biphasic catalyst is used

Answer 6

Ruhrchemie/ Rhone-Poulenc

Question 7

What does the monsanto process do?

Answer 7

synthesis of acetic acid by catalytic carbonylation of methanol.

Question 8

At high water concentration what is the rate determining step of the monsanto process?

Answer 8

oxidative addition

Question 9

at low water concentration what is the rate determining step of the monsanto process?

Answer 9

reductive elimination (due to precipitation of catalyst)

Question 10

What is the Cativa process? (BP)

Answer 10

formation of a carbonyl bond by migration