Science of Synthesis

Härtinger, S.; Härtinger, M., Science of Synthesis, (2007) 35, 568.

Radical iododecarboxylation can be achieved via the direct action of a peroxide radical initiator such as dibenzoyl peroxide or dialkyl monoperoxycarbonate ‌6‌ on aliphatic carboxylic acids (‌Scheme 2‌). In the presence of stoichiometric quantities of iodine an acyl hypoiodite is formed,[‌28‌] which rapidly decomposes in higher-boiling halogenated solvents, such as 1,1,2,2-tetrachloro-1,2-difluoroethane (Freon 112), 1,3-dichloropropane, 1,3-dibromopropane, 1,2-dichloroethane, or carbon tetrachloride.[‌5‌,‌29‌] The use of other peroxides including alkyl-, halo-, or nitro-substituted aroyl peroxides also affords iodoalkanes, in up to 90% yield.[‌5‌] With the use of peroxycarbonate ‌6‌, the production of iodoaryl side products can be minimized by employing higher ratios of iodine. Due to the decomposition of the isopropoxy radical, generated from the tert-butyl isopropyl peroxycarbonate ‌6‌, only the tert-butoxy radical is involved in the abstraction of a hydrogen atom from the carboxy group. tert-Butyl peracid esters ‌7‌, derived from a reaction of the corresponding acid chloride with tert-butyl hydroperoxide, undergo an analogous transformation.[‌23‌,‌30‌,‌31‌] A related homolytic decarboxylative transformation, which also leads to iodoalkanes, proceeds via the decomposition of aliphatic peroxyacetals in the presence of an alkyl iodoacetate as the iodine transfer agent.[‌32‌,‌33‌]

‌Meeeee 8‌ Meeeeeee-Meeeeeeee Meeeeeeeeeeeeee[‌8‌,‌88‌,‌88‌,‌88‌]

‌Meeeeeeeeee 8‌

M8	Meeeee	Meeeeeeeee	Meeee (%)	Mee
(MM8)8Me	M	8,8-eeeeeeeeeeeeeee, 888°M, 8 e	88	[‌8‌]
(MM8)88Me	M	8,8-eeeeeeeeeeeeeee, Meeee 888, 888°M, 8 e	88	[‌8‌]
(MM8)8Me	M	8,8-eeeeeeeeeeeeeee, 888°M, 8 e	88	[‌88‌]
Me	–e	MeMM, 88°M, 8 e	–e	[‌88‌]
	–e	MeMe, eeee, 888°M, 888 e	88	[‌88‌]

e Mee eeeeeeeee eee eee eeee-eeeee eeeeeee eeeee ‌8‌.

e Meeee eee eeeeeeee.

Meeeeeeeeeee eeeeeeeee

8-Meeeeeeeeeeeeee [‌8‌, M8 = (MM8)88Me]; Meeeeee Meeeeeeee:[‌8‌]

MMMMMMM: Meeeeee eeeeeeeee eee eeeeeeeeeee eeeeeeeee eeeeeeeee, eeeee eeee ee eeeeeee eeee eee eeee. Me eee eeeee ee eeeeeee ee eeeee ee eeeeeeee. Meeeeee eeeeeeee e eeeeeeeee eeee ee eeeeeeeee.

Me e eeeeeeee eeeeee eeeeeeee eeee e eeeeeeeeeeee eeee eeee eeeeee M8 (88.8 e, 88 eeee), eeeeeeeeeeee eeee (88.8 e, 88 eeee), MMMM (8.88 e, 88 eeee), 8,8-eeeeeeeeeeeeeee (88 eM), eee Meeee 888 (88 eM). Meee eeeeeee, e eeeeeeeeee eeee eee eeeeeeee, eeeee eee eeee ee 888°M eee 8 e. Mee eeeeeee eee eeeeeeeee eeee eee eeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeee ee ee Me8M eee eeeeee eeee ee Me8MM8 eee eee eeeeeee eeeee eee eeeeeeeeeeee. Meeeeeee MeMM eee eeeeeee ee eeeeeeeeeeeeee (eeeeee eee, eeeeeeeee eeeee) ee eeee eee eeeeeee eeeeeeeeee eeeee eeeeeeeeeeeeeeeee [eeeeeee/MeMM (88:88), 88 eM]; eeeee: 88 e (88%).

References