Duisburg Harbour 1963

An industrial process should proceed in 100% yield and be amenable to operation in a bathtub by a one-armed operator.

John Cornforth

What does industry want?What does industry want? TU Delft

Amount of waste/kg product:

Product tonnage E Factor

– Bulk Chemicals 104-106 <1 - 5

– Fine chemical Industry 102-104 5 - >50

– Pharmaceutical Industry 10-103 25 - >100

R.A. Sheldon, Chem & Ind,1997,12; 1992,903R.A. Sheldon, Chem & Ind,1997,12; 1992,903

The E Factor

Roger Sheldon

ATOM EFFICIENCY: STOICHIOMETRIC VS CATALYTIC OXIDATIONATOM EFFICIENCY: STOICHIOMETRIC VS CATALYTIC OXIDATION

Stoichiometric: The Jones Reagent (Sir Ewart Jones)

3 PhCH(OH)CH 3 + 2 CrO3 + 3 H 2SO4 3 PhCOCH 3 + Cr2(SO4)3 + 6 H 2O

Atom efficiency = 360 / 860 = 42%

Catalytic:

PhCH(OH)CH 3 + 1/2 O2 PhCOCH 3 + H2O Catalyst

Atom efficiency = 120/138 = 87%

Byproduct: H2O

Atom Economy: B.M.Trost,Science,1991,254,1471

Etheor = ca. 1.5

Etheor = ca. 0.1(0)

The Environmental Quotient EQ

EQ E(kg waste) × Q (Unfriendliness )

e.g. NaCl=1 ( arbitrary)

Cr salts= 1000?

CHROMIUM(VI): THE ORGANIC CHEMIST’S FAVOURITE OXIDANTCHROMIUM(VI): THE ORGANIC CHEMIST’S FAVOURITE OXIDANT

C10H13N2 + 3 OK2Cr2O7

C20H24N2O2 H2O+

1856 : Attempted synthesis of quinine (W.H.Perkin)

allyltoluidine

Led to the serendipitous synthesis of the first synthetic dyestuff mauveine (aniline purple)

N

MeO

HO N

quinine

2000 : “It’s hexavalent chromium, highly toxic, highly carcinogenic.

Gets into your DNA, so you pass the trouble along to your kids.”

Julia Roberts in ‘Erin Brokovich’

quinine

CATALYTIC VANILLIN SYNTHESIS: RHODIA PROCESSCATALYTIC VANILLIN SYNTHESIS: RHODIA PROCESS

S.Ratton, Chem. Today, March / April, 1998, p.33

Overall: C6H6O + H2O2 + CH3OH + H2CO + 1/2 O2 C6H8O3 + 3 H2O

OH OH

OH

OH

OCH3H2O2 CH3OH

solidcatalyst

La phosphate gas phase 250 Co

aq. H2CO

Acid catalyst

O2

noble metalcatalyst

OH

OCH3

CH2OH

OH

OCH3

CHO

4 steps, all employing a heterogeneous catalyst