I can think of the use of this in the reduction of phenylalanine to amphetamine, and reduction of tryptophan to AMT.
A Direct Reduction of Aliphatic Aldehyde, Acyl Chloride, Ester, and Carboxylic Functions into a Methyl Group
Gevorgyan, V.; Rubin, M.; Liu, J.-X.; Yamamoto, Y.
Journal of Organic Chemistry 66, 1672-1675 (2001) (https://www.thevespiary.org/rhodium/Rhodium/pdf/carboxylic2methyl.pdf)
(https://www.thevespiary.org/rhodium/Rhodium/pdf/carboxylic2methyl.pdf)
DOI:10.1021/jo001258a (http://dx.doi.org/10.1021/jo001258a)
Abstract
Aliphatic carboxyl groups was efficiently reduced to the methyl group by triethylsilane in the presence of a catalytic amount (5 mol%) of the non-traditional lewis acid B(C6F5)3. To the best of our knowledge, this is the first example of exhaustive reduction of an aliphatic carboxyl function to a methyl group. Aliphatic aldehydes, acid chlorides and acid anhydrides also underwent complete reduction under similar reaction conditions.
All yields from all the published substrates range between 91 and 99%.
Experimental conditions:
Triethylsilane (30 mmol) was added under an argon atmosphere to a mixture of the carboxylic acid (5 mmol) and B(C6F5)3 (0.25 mmol) in 5 ml DCM. The mixture was stirred at RT for 20h, the reaction quenched (Et3N, 0.25 ml), filtered through Celite and concentrated. The residue was mixed with 40% HF (5-7 ml) in ethanol (30 ml) and refluxed for 7h. Water (60 ml) was added, the product extracted with 3x30ml pentane, The extracts washed with water, dried over MgSO4 and the solvent and Et3SiH was removed under vacuum. The residue was purified by flash column chromatography on silica gel to afford the products in 91-99% yield.
Too bad 100g of the stuff costs $150 (Aldrich).
http://rhodium.lycaeum.org (http://rhodium.lycaeum.org)
The purpose of the sodium hydride (NaH) is the same as for NaOH, to deprotonate the OH groups on the aromatic ring. NaH does this more effectively and irreversibly than NaOH, as the reaction with sodium hydride goes PhOH + NaH => H2 + PhONa, while with hydroxide water is formed, and the reaction is reversible.
https://www.rhodium.ws (https://www.rhodium.ws)
I think I should have posted this study here, to keep the thread alive and keeping the theme going with new developments.....and so here it is,
Post 529479 (https://www.thevespiary.org/talk/index.php?topic=6978.msg52947900#msg52947900)
(java: "Reduction of Carbonyl Function to a Methyl Group", Chemistry Discourse)