04-09-03 06:13
No 424962
I have been researching the Borohydride reduction and have come up with conflicting reports.
Labtop states that the conditions for good yields must be very anhydrous (silicagel etc.).
Terbium states that scrupulously anhydrous conditions are not essential to good yields.
Barium then goes on to post in Post 328680 (Barium: "A really wet reductive alkylation", Novel Discourse) that aqueous solutions may be used with ~ 90% w/w yields.
These are all very respected and credible bees. This is what has led to my confusion.
Is it that Barium employs Toluene, which provides azeotropic properties to the equation, and therefore limits available H2O, that his yields are good?
If so, Would an even more azeotropic solvent (e.g. Dimethylsulfoxide or others) allow for even better yields?
Are anhydrous conditions essential?
Some bees that I have asked advice from, via P.M. (thanks again
), have given me advice that also conflicts.Can I have some advice on this issue?
Thanks, abolt
Every DOG has its day, L.J.
(Distinctive Doe)
04-09-03 07:53
No 424985
Are all three procedures you quote identical except for the water content?
Removeing water drives imine formation and that what anhydrous conditions are for, they don't have anything to do with the reduction necessarily. Water is a leaveing group and the reaction is actually an eqilibrium reaction even if most texts don't show that explicitly.
http://trc.ucdavis.edu/srdungan/fst100a/
http://chemistry2.csudh.edu/rpendarvis/i