Factor |
Approximate order of importance: |
Good |
Bad |
1 |
FUNCTIONAL GROUP COMPATIBILITY |
Conditions compatible with ALL the functional groups present molecule: |
Reagent/conditions not compatible or highly risky |
2 |
FUNCTIONAL GROUP EQUIVALENCE |
Same functional groups and same or very similar (steric) environment |
Functional groups are slightly different/have different steric environment |
3 |
AVAILABILITY |
Reagents in already available in lab |
Requires buying in reagent. |
4a |
EXPERIENCE |
Personal experience carrying out the reaction (or in the group) |
No available experience of the reaction |
4b |
RELIABILITY OF PROCEDURE |
Are the people who have done the reaction well known and reliable? |
People reporting the procedure have no known track record. |
4c |
RELIABILITY OF REACTION TYPE |
Is the reaction/reagent type well known with long history |
The reaction type/reagent is new or has little widespread use in the literature |
5 |
EASE OF CARRYING OUT THE REACTION |
No special apparatus required |
Requires special apparatus or handling conditions e.g glovebox.
High pressure vessel/gas cylinder etc |
6 |
COST |
Cheap
Note: depends where in sequence reagent occurs: If at end the quantity needed will be small and the substrate more expensive in proportion |
Expensive:
Not justifiable for type of transformation
Scale-up of reaction would be too costly for high throughput of material |
7 |
TOXICITY/RISK |
Non-toxic reagents required
|
Uses Toxic reagents:
Heavy metals: Cr/Hg/Sn/Pb/Se/
Toxic organic products: HMPA
Explosive: CH2N2 (and toxic!) |
8 |
COMMERCIAL AVAILABILITY |
Reagent commercially available |
Reagent requires synthesis |
9a |
EASE OF SETTING UP THE REACTION |
Non anhydrous conditions |
Strict anhydrous conditions required |
9b |
EASE OF CARRYING OUT THE PURIFICATION |
No excess reagents to remove |
Large excess of reagents to remove complicating chromatographic purification |
9c |
EASE OF CARRYING OUT THE WORK-UP |
Standard solvent |
Uses high boiling point solvent DMF/DMSO/DMPU
that have to be removed |