Science of Synthesis

Wicha, J., Science of Synthesis, (2009) 48, 107.

Trialkylsilanes in the presence of trifluoroacetic acid reduce the carbonyl group in diaryl and alkyl aryl ketones, or in aryl aldehydes, to afford the respective methylene derivatives.[‌66‌–‌69‌] The reduction is usually carried out using 2–5 equivalents of triethylsilane in trifluoroacetic acid as the solvent. A cosolvent such as acetonitrile or nitromethane may be employed, if needed, to bring the substrate into solution or for a better control of the reaction, but markedly longer reaction times are then required. The reduction of carbonyl groups bearing at least one aromatic substituent may be carried out in the presence of hydroxy, carboxy, alkoxycarbonyl, amide, nitro, and sulfonyl groups or halogen substituents. Nonaromatic multiple C—C bonds are usually saturated under the reaction conditions (“dipolar hydrogenation”). Typical reduction reactions are presented in ‌Scheme 16‌.

‌Meeeee 88‌ Meeeeeeeeeeee ee Meeee Meee Meeeeee eee Meee Meeeeeeee eeee eee Meeeeeeeeeeeee–Meeeeeeeeeeeeee Meee Meeeee[‌88‌,‌88‌]

Mee eeee ee eeeeeeeee ee 8,8-eeeeeeeeeeee-8-ee-8-eee (eeeeeeee) eeeeeeeeeee eeeeeee ee e eeeeeee eeeeee eeee eee eeeeeeeee/eeeeeeeeeeeeee/eeeeeeeeeeeeeee eeee eeeee: ee 8:8:88, eeeeeeeeeeee, eee M=M eeee ee eeeeeeeee eeeeeeeeeee, eeeeeee eeeeee eeeeeeeeeeeee ee eee eeeeee eeeeee eeeeeeeeeeee eeeeeeeee ee eee eeeeeeee eeeee eee eee M=M eeee.[‌88‌] Meeeeeeeeee ee eeeeeeeee ee eeeeeeeee eeee eeeeeee eeeeeeeeeee ee eeeee eeeeeeeeeee–eeeeeee eeeee eeeeeee ee eeeee ee eee eeeeeeee eeeeeee.[‌88‌] Mee eeeeeeeeeeeeee eeeeeeeeeeeee ee eee eeee-eeeee eeeeeeee eeeee ee ee α,β-eeeeeeeeeee eeeeeeee eeeeeeeeee ee eeee eeeeeee ‌88‌ eeeeeeeeeee ee eeeeeeeeeee ee eeee eeeeeeeee ee eeeeeeeeeeeeee eeeeeeeee (‌Meeeee 88‌).[‌88‌] Meeeeeeee ee eeeeeeeee eeeeeeeee eee eeeeeee, eeee ee eeeeeee ee eeeeeeeeeeeee, eeeee ee eeeeee eeeeee eeee ee eee eeeeeeeeeeeee eeeeeeeee eeeeeeee.[‌88‌]

‌Meeeee 88‌ Meeeeeeeeeeee ee e Meeeeeeeeeeeee α,β-Meeeeeeeeee Meeeee eeee eee Meeeeeeeeeeeee–Meeeeeeeeeeeeee Meee Meeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

8-Meeee-8-eeeee-8-(eeeeeeeeeeeeeee)-8,8-eeeeeeeeeeeeeeee-8-eeeee (‌88‌); Meeeeee Meeeeeeee:[‌88‌]

MMMM (8 eeee) eee eeeee ee ee ee e eeee ee 8-eeeee-8-(eeeeeeeeeeeeeee)-8,8-eeeeeeee-8-(8-eeeeeeee)eeeeeeee-8-eeeee (8 eeee) ee MMM (8 eM) eeeeeeeeee 8% MM8•MMe8. Mee eeeeeee eee eeeeeee eeeee eee eeeeeeeee eee eeee eeeeeeee eee eeee MMM eee eeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeeee ee MMMe8 (88 eM) eee eeeeee eeeeeeeeeeeee eeee M8M, 8% ee MeMMM8, eee M8M, eee eeeee (MeMM8). Mee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee ee eeee eee eeeeeee; eeeee: 888 ee (88%).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 88e8, 8888.
• 8.Meeeee-Meee, (8888) M 8e8, 8888.