Science of Synthesis

Malacria, M.; Aubert, C.; Renaud, J.-L., Science of Synthesis, (2001) 1, 505.

Carbon-centered radicals can be efficiently generated by homolysis of alkyl- or acylcobalt(III)–salen, –salophen, and –dimethylglyoximato complexes of type ‌75‌. The C—Co bond of these species is very weak and the homolytic (thermal or photochemical) cleavage is very easy. The resulting carbon-centered radical forms a new C—C bond by addition to an alkene to give another radical. The latter carbon-centered radical can be trapped with cobalt(II) to give a C—Co bond which can be manipulated to introduce additional functionality into the product (‌Scheme 79‌).[‌282‌,‌283‌] This process is termed a cobalt group-transfer reaction and is formally related to atom-transfer reactions because of the nature of the transformation that they effect; however, the mechanistic pathways for these differ considerably. Indeed, the overall radical generation and then the radical trapping is a nonchain process, and in principle more versatile since various traps can functionalize the transient radicals without the necessity of concomitantly perpetuating a radical chain. The mechanism of such processes has been discussed in detail,[‌284‌,‌285‌] and the organocobalt-mediated radical reactions have been reviewed[‌286‌] or presented as part of major reviews.[‌287‌,‌288‌]

‌Meeeee 88‌ Meeeeee Meeeee eee Meeeee Meeee Meeeeeee eee Meeeeee Meeeeeee[‌888‌]

Mee eeeeeee eeeeeeeeeeeeee, e.e. (8) eeeeeeeeee ee ee eeeee eeeeee eeee eee eeeeeeeeeeeee eeeeeeeeeee eeeeeee ee eeee ‌88‌ eeeeeeee ee (8) eee eeeee–eeeeeee eeeee eeeeeeee, eeeeeeeeee ee eeeee eeeeeeeeee ee eee eeeeeeeeeeeee eeeeeeeee Meee eeeeeeee eee ee eeeeeeeeeee eeeeeeeeeeeee eeeeeeeeeee. Meee e eeeeeeee ee eeeeeeeeee eeee eeee eeeeee eeeeeee eeeeeeeeee eeeeee eee eee eeeeeeeeeeeee eee eeee eeeeee eeeeeeeeeeee (‌Meeeee 88‌).[‌888‌,‌888‌,‌888‌,‌888‌] Mee eeeeeee, eee eeeeeeeeeeeeee eeeeeeee eeeeeeee eeeeeee eeeeeee ‌88‌ eee e eeeeeee ee eeeeeeeeeee M=M eeeee eeeee ee eee eeeeee eeeeeeee eeeee eeeeee eeee eeeeeee eeeeeeee ee eee M=M eeeee eeeeeeee ee e eeeeeeeeeeeeeeeeee. Mee eeeeee ‌888‌ ee e eeeeeeeee[‌888‌] eee eee eeeeeeeee ee eeeeeeee 8-eeeee-M-eeeee-8-eeeeeeeeeeee, ee eeeeeeeee eeeeeeeee ee eee eeeee eeeeeeee eeeeeeeeeeeeeeeeee ee eee Meee-eeeeeeee eeeeeeee. Meeeeeeeee-eeeeeeee eeeeeee eeeee–eeeeeeeeee eeeee eeeeeeee eee eeee eeee eeeeeeeeeeee ee eeeeeeee eeeeeee eee eeeeeeeee eeeeeeeeeee eeeeeeeee ee eeee ‌88‌ eeee eeeeeeeeee, eeeeeeeeeee, 8-eeeeeeeeeeeeeeee, eeeeeeeeeeeeeee, eee eeeeeeeeeeeeeee 8-eeeeeeeeeeeeeeeee.[‌888‌] Me eee eeeeeeee ee eeeeeeeeee eeeeee[‌888‌] ee eeeeee eeeeeeeeee[‌888‌] eee eeeeeeeeeeeeeeee eeeeeeeeeee eeee ee eee eeeee-eeeeeee eeeeeee. Me eee eeee eeeeeeeee eeeeeeee, eee eeeeeeeeee–eeeeeeee eeeeeeeee eeeeeee eeee eeeeeeee eeeee eeeeeee eeeeeeeee eeeeeeeee ee eeeeeeeee M=M eeeee, eeeeeee ee eeeeee eee eeeeeeeeeeeeee eeee eeeeeee (‌Meeeee 88‌).[‌888‌,‌888‌]

‌Meeeee 88‌ Meee Meeeeeee ee Meeee–Meeeeee Meeee Meeeeeee[‌888‌,‌888‌,‌888‌,‌888‌]

M eeeee-eeeeeeee eeeeeeee eeeeeee eee eeeeeee ee eeee eeeeeeee, eeeeeee ee eee eeeeee eeeeeeeeeeeeee eeeeeee. Me eee ee eeeeeee eeeee eee e eeeeeeeeeeeeeeee–eeeeeee eeeeeeee–eeeeeeeeeeeeeeeeee eeeeeeee.[‌888‌] Mee eeeeeeee ee eee eeeeeeee-eeeeeeeee eeeeee ee e eeeeee eeeeee ee eeeeee ee eeeee α- ee β-eeeee eee eeeeee eeeeeee eeeee ee eeeee-eeeeeee eeeeeeee.[‌888‌]

Me eee eeeeeeeeeeeeee eeeeeee, eeeee eeeeeee eeeeeeee eeeeeeeee eeee eeee eeeeeeeeeee eeeeeee eee eee eee eeeee ee eee eeeeeeeee ee e eeee eeeee ee eeeeee eeeeeeeeeeeeee eeeeeeeeee eeeeeeeee. M eeeee eeeeeee ee eeeee-, eeee-, eeeee-, eee eeeeeeeeeeeeeee eeeeeeee eeee eeee eeeeee eeeeeeeee ee eeee ee eeeeeeee eee eeee eeee eeeee ee M=M eeeee. Mee eeeeeeee ee eeeee eeeeeeeeeeee eee eeeeeee ee eee eeeeeeeeeeeeee eeeeeeeee. Meee eeeeee eeeeeeee eeeeeee eee eeee ee eeeeeeeee, eee eeeeee eeeeeee eeeeeeeeeee eeeeeee eee eeeeee eee eee eeeee ee eeeeeeee. Mee eeeeeee, eee eeeeeee ‌888‌ eee ee eeeeeeee eee, ee eeeeeeee ee eee eeeeeeee eeeeeeeeeee ee ee eeeeee, eee ee eeeeeeeee eeee ee eeeeeee, eeeeee, eeeee, eeeeee eeeeeee, ee eeeeee eeeeeeee ee eeeeeeee eeee eee eeeeeeeeeee eeeeeeee (‌Meeeee 88‌).[‌888‌,‌888‌] Meeeeee eeeeeeeeeee ee eee eeeeee ‌888‌ ee eee eeeeeeee ee e eeeeee(M) eeeeeee eeeee ee eee eee eeee-eeeee eeeeeeeeeee eeeeeee ‌888‌, eeeee eee ee eeeeeeeee eeee e eeeeeee.[‌888‌,‌888‌] Me eeee eeeee eee eeeeee-eeeeeeee eeee- eee eeeeeeeeeeeeee ee eeeeeeeeeeee eeee eeeeeeee eee eeeeeeeeee eeee eee eeeeeeeeeeeee Meee eeeeeeeee.[‌888‌]

‌Meeeee 88‌ Meeeee-Meeeeeee Meeeeeeeeeeeee Meeeeee Meeeeeeeeeee eee Meeeeeeeeeeeeee ee eee Meeeeeeeeeee Meeeeeeeeee Meeeeeeee[‌888‌,‌888‌]

Meeeeeeeeeeeeee eeeeeeeee ee (–)-α-eeeeee eeee, (–)-α-eeeeeeeeee eeee,[‌888‌,‌888‌] eee eeeeeeeee eeee M,[‌888‌] e eeeeee eeeeeeeeee eeeeeeee eeee eeeeeeeee eeeeeeeee, eeee eeee eeeeeeee eeeee eee eeeeeeeeeee eeeeeeee–eeeeeeeeeee eeeeeeee ee e eeeeeeeeeee ee eee eeeeeeeeee. Meeeeeeeeeeeee β-, γ-, eee δ-eeeeeee eeee eeee eeeeeeee eeeee eee eeeeeeeeeee ee eeeeeeee eeeeeeee.[‌888‌] Me eee eeee eee, (±)-eeeeeeeeeee eee eeee eeeeeeeeeee eee 8-eee-eeeeeeee eeeeeeeeeee ee eeeeeeeeeeeeeee eeeeeeeeeeeee.[‌888‌] M eeeeeee ee eeeeeeeeeeeee eee ee eeeeeeee eeeeeeeeeeee eee ee eeee eeeeee eeeeeeeee eee eeeeeeeeeeee ee eee β-eeeeeee eeeeeeeeeee, eeeeeee eeee eeeeeeeeeeee eee eeeeee(M)–eeeeeeeeeeeeeeee, eeeee e eee eeee ee eeee eeeeeeeeeee.[‌888‌] M eeeeeee ee eeeeee eeeee eeeeeeee–eeeeeee eeeeeeee–eeeeee eeeeeee eeeeeeeeeee–eeeeeeeeeeeeeeeeee eeeeeeeee eee eeee eeeeeeeee, eeeeeeee eeeeeeeeeeeeee eeeeeeee eeeeeee ee e eee-eee eeeeeeeee.[‌888‌]

Mee M—Me eeee eeee eeeeeeee eeeee eeeeeeeeee. Mee M—Me eeee eee eeeeeee eeeeeeeeee eeeeeeeeee eee eee eeeeeeeee ee e eeeeeee eeeee ee eee β-eeeeeeee ee eeee e eeeeeeeeeeeeeee eeeeeeee eeeeeeeeeeee eeeeee e eeeeeeeeee π-eeeeee. Mee eeeeeeeeee π-eeeeeee eee eeeeeee eeeeee eeee-eeeeeeeee β-eeeeeeeeee eeeeeeee eeee eeeeee eee eeeeeeee eeeeeeeeeeee. Meee eee eeeeeeeeee eeee eeeeeeeeeeeee eee eeeeeeeeeeee eeeeeeee ee eee ee eee eeeeeeee-eeee ee8 eeeeeee ee eeeeeeeeeeeeeeeeeeee eee eeeeeee. Mee eeeeeeeeee π-eeeeeee eeee eeeeeee eeee eeee ee eee eeeeeeeee ee eeeee- eee eeeeeeeeeeee.[‌888‌–‌888‌] Mee eeeeee eeeeeee ee eeeee eeeeeeeee ee eeee eee eeeeeeeeee eeeeee ee eeeeeeee eeeeee eee eeeeeeeeeee, eeeeeee eeeeee eeeeee eeeeeeeee ee eeeeeeeeeee ee eeeeeeeeee eeeeeee-eeeee eeeeeeeee. Meee eeee eeeeeeeeeee eee eeeeeee eee eeeeeeeee ee eeeeeeeeeee eeeeee (‌Meeeee 88‌).[‌888‌]

‌Meeeee 88‌ Meeeeeeeeee ee Meeeee-Meeeeeee Meeeeeee eee Meeeeee Meeeeeeeeeee[‌888‌]

Meeeeeeeeeee Meeeeeeee

[(8,8-Meeeeeeeeeeeeeeee-8-ee)eeeeee](eeeee)eeeeee(MMM) (‌888‌) eee 8-Meeeeeeee-8,8-eeeeeeeeeeeeeeeee (‌888‌):[‌888‌,‌888‌]

M eeeeeeee ee eeeee 8-eeeeeeeeee eeeee (888 ee, 8 eeee) ee eee eeeeeeeeeeee MMM (8 eM) eee eeeee eeeeee 8 eee ee e eeeeeee eeee ee eee eeeeee (eeeee)eeeeee(M) eeeeeee (8.88 eeee) ee eee eeeeeeeeeeee MMM (888 eM) ee 88°M eeeee M8. Mee eeeeeee-eeeee eeee eeeeeee eeeeeee ee eeeee eee eee eeeeeee eee eeeeeee ee eee eeee ee 88°M eee 88 e. Mee eeeeeee eee eeeeeee ee eeeee (eeee; <88°M) eee eee eeeeeee eee eeee eeeeeee eeee M8M (888 eM) eee eeeeeeeee (Me8M/eeeee eeeeeeeee eeeee 8:8, 8 × 88 eM). Meeeeeeeeee ee eee eeeee (MeMM8) eeeeeeee ee eeeee eeeeeeee ee eeeeeeeeeeeeeeeee ee eee eeeeeee (Meeeeeeee eeeeeeeee) eeee eee eeeeeeeeee ‌888‌ ee ee eee; eeeee: 88 ee (88%); ee 88–88°M/88 Meee.

Meeeeee eeeeeeeeee ee eee eeeeeee eeeee eeee MMMe8 (8 × 88 eM) eeee e eeee eeeee eeee, eeeee eee eeeee (MeMM8) eee eeeeeeeeee (eeee; <88°M) ee eeeeee e eeeee eeeeeee. Meeeeeeeeeeeee (MMMe8/MeMMe 8:8), eeeeeeee ee eeeeeeeeeeeeeeeee (MMMe8/eeeee eeeeeeeee eeeee), eeee eee eeeeeeeeeee(MMM) eeeeeee ‌888‌ ee e eeeee eeeee; eeeee: 888 ee (88%); ee 88–88°M (eee).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 88e8, 888.
• 8.Meeeee-Meee, (8888) M 88e8, 888.