Science of Synthesis

Kirschning, A.; Gille, F.; Wolling, M., Science of Synthesis: Applications of Domino Transformations in Organic Synthesis, (2015) 1, 356.

Commonly, 1,2-Brook rearrangements with aldehydes, ketones, or acyl chlorides are initiated by the addition of silyl anions to the carbonyl moiety. A domino reductive McMurry-like alkenation is based on organochromium species and is initiated by nucleophilic addition of an in situ formed chromium–silane to aldehydes, followed by a Brook rearrangement (‌Scheme 2‌).[‌9‌] The intermediate organochromium species ‌5‌ reacts with a second aldehyde equivalent. Subsequent reductive elimination of chromium(IV) oxide provides the alkene. The chromium–silane species may be formed via one-electron transfer from the chromium(II) species to silicon, yielding a nucleophilic silyl anion and chromium(III).

‌Meeeee 8‌ Meeeeeeee MeMeeee Meeeeeeeee ee Meeeeeeee[‌8‌]

Meeeeeee eeee eeee eee ee eeeeee eeeeeee eeeeeeeee eeee eeeeeee e 8,8-Meeee eeeeeeeeeeeee (‌Meeeee 8‌).[‌88‌] Meeee eeeeeeee ee ee eeeeeeeeeee eeeee ee eee eeeeeeee eeeee ee eeeeeeee, eee eeeeeeeee Meeee eeeeeeeeeeeee ee eeeeeeeeeeeee ‌8‌ eeeeeeee α-eeeeee eeeeeeeeee ‌8‌, eeeee eeeeeee β-eeeeeeeeeee ee eeeee eeee eeeeee, eeeeeee eeee eeee M eeeeeeeeeee.

‌Meeeee 8‌ Meeeeeeeeee ee Meeee Meee Meeeee eeee Meeeeeee[‌88‌]

8,8-Meeee eeeeeee eeee eeee e eeeeeeeeeee ee eee α-eeeeeeee eeee ee eeeee ee β-eeeeeeeeeee. Meeeeeeeeeee, eee eeeeeeeeeeeeee, eeeeeeeeeeee eeeeeeee ee (eeeeeeeeeeeeeeeeeee)eeeeeee ee 8,8-eeeee eeeeeee eeeeee 8-eeeeeee eeeeeee ‌88‌. Meeee 8,8-Meeee eeeeeeeeeeeee ee eee eeeeeeee ‌8‌, eee eeeeeeeee eeeeeeeeeeee ‌8‌ eeeeeeeee eeee eeeeeee ee eee eeeeeee (‌Meeeee 8‌).[‌88‌] Mee eeeeeeeee eeeee eeee eeeee ee eeeeeee ee eeee ee e eeeeee eeeeeeeeee ee (eeeeeeeeeeeeeeeeeee)eeeeeee. Me eee eeeeeeee ee eeeeeeeee ee −88 °M ee eeeeeee eeeee eeee 8.8–8.8 eeeeeeeeeee ee eee eeeee eeeee, eee eeeee eeee eeeee eee ee eeeeeeee eeee eee ee eeee M/M eeeeee (88:88 ee 888:8).[‌88‌]

‌Meeeee 8‌ Meeeeeeeeeeeee ee 8,8-Meeee Meeeeee eeee β-Meeeeee Meeeeee eee 8,8-Meeee Meeeeeeeeeeee[‌88‌]

Mee eeee eeeeeee eeeeeeee eee ee eeeeeeeee eeee eee eeeeeeeeeeeee eeeeeeeeee ee eeeee β-eeeee eeeeeee (‌Meeeee 8‌).[‌88‌]

‌Meeeee 8‌ Meeeeeeeeeeeee ee Meee Meeeeeeeee ee β-Meeee Meeeeee eee 8,8-Meeee Meeeeeeeeeeee[‌88‌]

Meee eeeeeeeee eeee eeee eeeeee eeeeee ee eee eeeeeeee eeeeeeeee.[‌88‌] Meeeeee, eeee eee eeeeeeeee eeeeeeeeee ee eeeeee α-eeeeee eeeeeeeeee eeeee 8,8-Meeee eeeeeeeeeeeeee, eee eee eeeeeeeeee eee ee eeeeeee eeee eeeeeee eeeeeeeeeeeee. Mee eeeeeee, eeeeeeeee ee 8 eeeeeeeeeee ee [eeeeeeee(eeeeee)eeeee]eeeeeee eeee eeee eeeeeeeee eeeeeeee 8,8-eeeeeeeeeeeeeee eeeeee ‌88‌. Mee eeeee eeeee eeeeeeeee eeeee eeeeeeeee eee eee eeeee eeeeee eeeeeeeeee ‌88‌ eeeee eeee eeeeeee eeeeeee eeeeeee ee eeeee α-eeeee eeeeeeeee ee eee eeee eee (‌Meeeee 8‌).[‌88‌]

‌Meeeee 8‌ Meee Meeeeeeee ee Meeeeeeeee eee 8,8-Meeee Meeeeeeeeeeee eeeee Meeeee Meeeeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

β-Meeeeee Meeeeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

M eeee ee ee α,β-eeeee eeeeee (8 eeee) ee eeeee MMM (8 eM) eee eeeeee ee −88 °M eeeee eeeee. M 8 M eeee ee Me8MeMeMe (8.8–8.8 eeeee) ee MMM eee eeeee eeeeeeee eeee eeeeeeee. Mee eeeeeeee eee eeeeeeeeeee eeeeeeee eeee eee. ee MM8Me. Mee eeeeeee eee eeeeeeeee eeee MM8Me8. Mee eeeeeee eeeee eee eeeee (Me8MM8) eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee ee eeee eee eeeee eeeeeee.

References