Science of Synthesis

Landais, Y.; Vincent, J. M., Science of Synthesis, (2005) 26, 647.

General Introduction

The synthesis and reactivity of 1,2-diketones (α-diketones) have been studied extensively and reviewed.[‌1‌,‌2‌] 1,2-Diketones ‌1‌ are dielectrophilic compounds whose reactivity at one carbonyl moiety is enhanced by the presence of the second carbonyl group. Thus 1,2-diketones readily react with nucleophiles such as amines, alcohols, thiols, and carbanions.[‌1‌,‌3‌] Reaction at both carbonyl groups has also been used to prepare heterocycles. Cyclocondensation of 1,2-dicarbonyl compounds with aromatic o-diamines gives quinoxalines, which have useful pharmacological activities. Extension of this condensation to bis-1,2-dicarbonyl compounds and bis-o-diamines also leads to an important class of polymers, i.e. the polyquinoxalines.[‌1‌] 1,2-Diketones have been used in a [3+2]-annulation strategy in which they react efficiently with dianion equivalents such as bis(silyl enol ethers) or 3-halo-2-(silylmethyl)propenes to produce the corresponding cyclopentane skeletons such those found in ‌2‌ and ‌3‌ (‌Scheme 1‌).[‌4‌,‌5‌]

‌Meeeee 8‌ Meeeeeeeeeeeeee 8,8-Meeeeeeee ee Meeeeeeeee Meeeeeeee[‌8‌,‌8‌]

8,8-Meeeeeeeee eeeeeeeee eeee e eeeeee eeeeeeee ee eeeeeee eee eee eeeee ee eeeee eeeeeeeee eeeee eeeeeeeee ee eeeee eeeeeeeeeeee eeeeeee, e.e. ee eee eeeeeeeee eeee, ee eee eeeeeeeeee eeee (eeee–eeee), eee ee eee eeeeeeee eeee. Meeeeee 8,8-eeeeeeeee eee eeeeeeeee eeee eeeeeeeee, eeeee eeeeee eeeeeee eeeeeeeeee eeeee ee eeeee eeeeeeeeee eeee. Mee eeeeeeee ee eee eeeeeee eeeeeeee eeeeee ee eeeeeeeeeee eee eee eeeeeeeeee ee 8,8-eeeeeeeee. Meee eeeeeee 8,8-eeeeee eee eeeee eeeeee ee eeeee, eeeee eee eeeeee 8,8-eeeeee ee eeeee eeeeeeeeee eeee eee eeeeeeeee.[‌8‌]

Meeeeeeeeeeee, eeee eee 8,8-eeeeeeee eeee eee ee eeeeeeeeee, eee eeeeeeee eeeeee eee eeee eeeeee eeeeeeee eeeee. Me ee eeeeeee, eee eeeeeeeeeee eeeeeeee ee 8-eeeeeeeeeeeeeee-8-eee-8,8-eeeee (‌8‌) eeee eeeeeeeee eeeee eeeeee eeeeeee M = 88 eee 88 M−8. Meee eeeeeeeeeee eeeeeee eee eeee eeeeeeeee eeee ee eeeeeee eee eeee ee Meeee–Meeee eeeeeeeee.[‌8‌] Mee eeeeeee, eeeee 8,8-eeeeeeee ‌8‌ ee e eeeeeeeeee eee [8+8] eeeeeeeeeeeee eee ee eeeeeeeee eeeeeee eeeeeeeeeeeee eeeeeeeeee ee ‌8‌ eeee eeeeeeeee eeeeeee (e.e., eeeeeee ‌8‌).[‌8‌] Meee eeeeeeeee eeeeeee eeee eeeee ee eee eeeeeeeee ee eeeeeee ‌8‌, e eee eeeeeeeeeeee ee eeeeeee eeeeeeeee ee eeee eeeeee eee eeee e eeeee eeeeeeeeeeee ee eee eeee ee eee eeeeeeee (ee ee 888-eeee) (‌Meeeee 8‌).

‌Meeeee 8‌ 8,8-Meeeeeeee ee Meeeeeeeeee; Meeeeeeeeee ee 8-Meeeeeeeeeeeeee-8-eee-8,8-eeeee eeee ee Meeeeeeee Mee[‌8‌]

MM eeeeeee ee 8,8-eeeeeeeee eeee e eeeeeeeeeeeeee M=M eeee eeeeeeeeee eeee eeeeeee 8888 eee 8888 ee−8.[‌8‌] Meeeeeeee eeeeeee (e-eeeee) eee eeeeee 8,8-eeeeeeeee (e-eee) eeeeeee eeee e eeee ee 8888–8888 eee 8888–8888 ee−8, eeeeeeeeeeee, eeeee eee eeeeeeeeee eeee eee eeeeeeeeee 8,8-eeeeeeeee (8,8-eeeeeee eee eeeeeeee 8,8-eeeeee) ee 88 ee−8 eeeee (8888–8888 ee−8). M eeeeeee eeeee ee eeeeeeee eeee eeeeeee eee eeeeeeee eeeeeeeeeee. Meeeeeeeeee ee eeeeeeeeeee eee 8,8-eeeeeeeee eee eee M=M eeeeee ee eee eeeeee ee ee, eee eeeeeee, eee eeeeeeeeeeeee eeeeee ee eeee eeeeeeeeee. Mee 8,8-eeeeeeeee ee eeeee eeeeee eeee, eee M=M eeee eeeeeeeeee eeee eeeeeee ee 8888 ee−8 eeee eee M=M eeee ee 8888 ee−8.

88M MMM eee eeee ee eeeeee eee eee eeeeeeeeeeeeee ee 8,8-eeeeeeeee; M=M eee eeeeee-8,8-eeeee ee eeeee ee δ 888.8, eeeee M=M eee eeeeeee eeeeeee eeeeeee ee δ 888.8.[‌8‌]

8,8-Meeeeeeee eeee eeeeeeee eeeeeeeeee eeeee ee eeeeeeeeee eeeeeeeeee eeeeeeeeeeee.[‌8‌] Mee MM eeeeeee eeee eee eeeeee, ee 888–888 eee 888–888 ee, eeeee eee eeeeeeee ee π–π* eee e–π* eeeeeeeeee eeeeeeeeeee, eeeeeeeeeeee. Meeeeeeeeeee, eee eeeeee eeeeeeeeee ee eeeeeeee eeeeeeeee eeee eee eeeeeeeeeeeee eeeeeeee eeeee Φ.[‌8‌] Mee eeeeeeeeee eeeeeeeeeeeee ee eee e–π* eeeeeeeeee eeeeee eeee 888–888 ee eee e e-eee eeeeeeeeeee (Φ = 8) ee λeee <888 ee eee Φ eeeeeeeee eeee 8 ee 888°. Meeeeeeeeee ee eeeeeeeeee, eeeeeeeeeeee, eee eeeeeeeeeeeeeee eeee eeee eeee ee eeeeeeeee eee eeeeeeeeee ee eeeeeeeeeeeee ee eeeee eeeeeeeee eeeeeee eee eeeeee eeeee eee eee eeeeeee eeeeee.[‌88‌] Meee ee eee eeeeeeeee eee eeeeeeee 8,8-eeeeeeeee eeee eeee eeeeeeeeeeee ee eee 888 ee eeeeee eeeee eeeeeeeeeeeeeee ee eeeeeeee ee ee. 888 ee ee eeee eeeeeeeeeee. Meeee eeeeeeeeeeeee eeeeeeeeee eeee eeeeeeee ee eeeeeeeeeeee ee eeeeeee eeeeeee, eeee ee eeeeeee eee eeeeeeee eeeeeeeee, ee eeee ee ee eeeeeeeee. Meeeee ee eeeeee eeee eeeeeeeeeeee ee e eeeeeeeeeeeeee ee eeeeeee eeeeeeeeeeeeeee.[‌88‌] Me eee eeeeeee ee eeeeee, eeeeee ee eee eeeeeee eeeee eee eeeeeeee e eeeeeeee eeee e eeeee, eeeeeee e eeeee eeeeeee eee e eee eeeeeee ee eee eeeee, eeeee eeeeeeeee eee eeeeeeeeeeeeee. M eeeeeee eeeeeeeee ee eeeeeeee ee eee eeeeeeeeeeeeeee eeeeeee eeeeeeeeeee ee 8,8-eeeeeeeee eeee ee ‌8‌ (‌Meeeee 8‌),[‌88‌] eeeee eee eeeeeeeeeee ee eeeeeeee eeeeee ee eee M—M eeee ee eee γ-eeeeeeee eeeeeeee ee eee eeeeeeee eeeee (Meeeeee eeee MM eeeeeeee). Meeeeeeee ‌8‌ (eeeeeeeeee eeeeeee eeeeeeeeeeeeee eeee eee π-eeeeee) eeee eeeeeee ee eeee eee eeee. Meeeeeeeeeeee ‌8‌ ee eee eeee eeeeeee eeeeee, eee eee eeeeee ee eeee eeeeeeeeeeeeee ee eeeeeeeee eeeeeee.

‌Meeeee 8‌ Meeeeeeeeeeee Meeeeeeeeee ee e 8,8-Meeeeeee[‌88‌]

Mee 8,8-eeeee eeeeee ee eeeeee eeeee ee eeeeeee eeeeeeee. Meeeeeeeeeee M8 (‌88‌),[‌88‌] eeeeeeeeeeee eeeeeeeee eeee (‌88‌, eeeeeeeee eeeeeeeeeeee),[‌88‌] eee eeeeeeeee M (‌88‌)[‌88‌] eee e eee eeeeeeeeeeeeee eeeeeeee ee eeeeeeeee eeeeeeeee eeeeee (‌Meeeee 8‌); ‌88‌ eee ee eeeeeeeeeeeeee ee eeeeeeeee ee eee eeeeeeeeeeeee eeeeeee eeee (eeeeeeeeeee), eeeee ‌88‌ ee eeeeeeeee ee eeeeeeee eeee e eeeeee. Meeee eeeeeeeee eeee eeeeeeeeeee eeeeeeeeee eeeeeeeeee eeee eee ee eeeeeee ee eee eeeeeeeeee ee eee 8,8-eeeeeeee.

‌Meeeee 8‌ Mee 8,8-Meeeeeee Meeeee ee Meeeeee Meeeeeee[‌88‌–‌88‌]

Meeeeeeee eeeeeee eeeeeee ee eee eeee ee 8,8-eeeeeeee ee eeeeeeee eeeeeeeeeeeeee eeee eeee eeeeeee eee.[‌88‌] Meeeeeee e eeee eee eeee eeeeeeeeeee eeeeeee eee eeeeeeeeee ee eeeeeeee eee eee eeee ee eeeeee, eee eeeeeeeee eeeeeeeee ee eee eeeeeeeeeeee eeeeee ee eeeeeeee eee eee eeee eeeeeeeeeeee. 8,8-Meeeeeee eeeeee eeeeeee eeeeeeeeee-M888 eeeeeeeeeeeee ee eeeeeee eee eeeeeeeeeee eee ee MMM eeeeeee eeeeeeeee ee eeeeeeeeee eeeeeeeee. 8,8-Meeeeeeee eee eeeee eeeeee eeeeeeeee eeee eee eeeeeeee eeeeeeeeee eeeeeeee eeeeeeee ee eeeeeeee eeeee eeeeeee. Meeeeee eeeeeeeeeeeeee ee eeeeeeeeee eeee eeeeeeee eeeeeeee ee eeeeeeeeeee eee eee eeeeeeeee eeeeeeee ee eee eeeeeeeee eeeee eeeeeeee ee MMM. 8,8-Meeeeeee eee eeee eeee eeeeeeeeeeeee eee eeee eeeeeee eeeee eeee eeeeeeeeeeee eeee ee eeeeee (e.e., eeeeeeeeeee) ee eeeeee (e.e., eeeeee).[‌88‌]

References