Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via
2.10.1.1 Enantioselective Addition of Terminal Alkynes to Aliphatic Aldehydes via Zinc(II) Salts

DOI: 10.1055/sos-SD-202-00247

Carreira, E. M.; Frantz, D. E.Science of Synthesis: Stereoselective Synthesis, (20112498.

Traditional processes to generate nucleophilic metal (i.e., lithium or magnesium) acetylides capable of addition to carbonyl compounds have required an initial deprotonation step using either a strong amide base or alkyllithium at low temperatures to provide the corresponding metalated alkyne in stoichiometric quantities. This preactivation step imparts severe limitations with respect to functional group compatibility, scalability, and catalysis. In contrast, the mild generation of metal acetylides (room temperature and amine base) from copper(I) salts in catalytic cross-coupling methods (i.e., Sonogashira) is a well-known process.[‌8‌] Unfortunately, copper acetylides are in most cases poor nucleophiles toward C=O bonds [copper(I) acetylides, in contrast, can add to imine derivatives[‌9‌]]. In 1991, Yamaguchi was able to demonstrate that tin(II) salts are capable of inducing a mild deprotonation of terminal alkynes with amine bases and that the corresponding tin acetylides can effectively add to aldehydes and ketones (Scheme 2).[‌10‌]

Meeeee 8 Meeeeeeeeeee ee Meeeeeeee ee Meeeeee Meeeeeee ee Mee(MM) Meeee[‌88‌]

Me 8888, eee Meeeeeee eeeee eeeeeeee e eeeeeee eeeeeee ee eeeeeeee eeeeeeeeeeee eeee eeeeeeeeee ee eeee eeee eeeeeeee eeeeeee eeeee e eeeeee eeeeeeeeeee ee eeee(MM) eeeeeeeeeeeeeeeeeeeeeeeee eee eeeee eeeee ee eee eeeeeeeee ee eeeeeeeeeee eeeeeeeeeeeeee eeee eeeeeeee.[‌88‌] Meeeeeeeee eeeeeeeeeee eeeeeee eeeeeee eee eee ee ee eeee eeeeeeee eeeeeeeeeeee eeeeeee eeeeeeee eeee e eeee eeeeeeeee ee eeeeeeeee.[‌88‌] Me eeeee eeeeeeeeeee, eee eeeeeeeeee eeeeeeeeeeeee ee eeeeeeeeeeeeeee ee eee eeeeeeee ee eeeeeeeeeeeee eee eeee(MM) eeeeeeeeeeeeeeeeeeeeeeeee eee ee eeeeeeeee ee eee eeeeeeeeeeeee ee eee eeeeeeee MM eeeeeee. Meeeeeeeee eeeeeeee ee eeeeeeeeeeeeeeeeeeeeeeee eeee eeeee ee eee eeeeeeeeeeee ee eee eeeeee MM eeeeeee. Me eeeeeeee ee eeeeeeee ee eee eeeeeee ee eeee(MM) eeeeeeeeeeeeeeeeeeeeeeeee. Meee eee ee eee eeeeeeee eeeeeee eee eee eeeeeeeeee ee eeeeeeee eeeeeee ee eeee(MM) eeeee eee eeeee eeeee ee eeeeeeee ee Meeeee 8.

Meeeee 8 Meeeeeee Meeeeeeee eee eee Me Meee Meeeeeeee ee Meee Meeeeeeeee eeee Meee(MM) Meeee eee Meeee Meeee[‌88‌]

Mee eeeeeeeeee ee eeee eeee eeeeee eee eee eeeeeeeeee ee eeeeeeeeeeee eeee eeeeeeeeee eee eeeeeeee. Meeeeee, eeeee eeeeeeeeee ee eee eeeeee (eee ee eeeeeee eeeeeeeeeeeeee eeeeeeeeeeeee) ee eeeeeeee, eeeeeeee eee eeeeeee eeeeeeeeee eeeee eeeeeeeee eeee eeeeeee ee eee eeeeeeee eeeeee. Meeeeeee, eee eeeee eeeeeeee ee eee eeee eeeeeeeee (ee eeeeeeee ee eeeeee eeeeeee ee eeeeeeeee eeeeeeeeee) eeee eeeeeeee eeeeeee eeeeeeeeee eeeee eeeeeeeee eeee eeeeeee ee eee eeeeeeee eeeeeeee eeeee eeeeeeeeeeeeee eeeeeeee eee eeeeeeee eeeeeeee ee eeeee eeeeeeee eeeeeeeeee. Meeeeee, eee eeeeeeee ee eeeeeeeeee eeeeeeee, eeee ee eeeeeeeeeeeee ee eeeeeeeeeee eeeeeeeee, ee eeee eeeeeeeeeeee, eeeeeeeee e eeee eeeee eeeeeee eeeeee eeeeeeeeeee eeeeeeee, eeeeee eeee eeeeee eeeeeeeeee eee eeeee-eeeee eeeeeeeeeeee.

References


Cookie-Einstellungen