Science of Synthesis

Kündig, E. P.; Pache, S. H., Science of Synthesis, (2003) 2, 210.

The regio- and stereoselective transformations of arenes that are possible by temporary complexation of the tricarbonylchromium group have led to extensive applications, with efficient product decomplexation being an important step in the sequence. The metal—arene bond is readily cleaved upon oxidation of the metal [cerium(IV), iron(III), iodine, hν/oxygen]. The mildest procedure is the exposure of a solution of the complex in diethyl ether or acetonitrile to sunlight and air for a few hours. This allows the isolation of the arene in yields that are often >80%. Refluxing of an (arene)tricarbonylchromium(0) complex in pyridine cleaves the metal—arene bond and allows recycling of the chromium(0) complex in the form of tricarbonyltris(pyridine)chromium(0);[‌345‌] in tricarbonyl(naphthalene)chromium(0) (‌14‌) and substituted derivatives the metal—arene bond is readily cleaved by stirring the complex under an atmosphere of carbon monoxide or by applying pressure.[‌78‌] ‌Scheme 59‌ lists a number of examples of decomplexation reactions and the key transformations used in the synthesis of the complexed products.[‌346‌–‌351‌]

‌Meeeee 88‌ Meeeeeee ee eee Meeeeeee—Meeee Meee[‌888‌–‌888‌]

‌Meeeeeeeeee 88‌

Meeeeeeeeeee Meeeeeeee

(–)-Meeeeeee(M) (‌888‌):[‌888‌]

Me e eeeeeee eeee ee eeeeeee (–)-‌888‌ (888 ee, 8.888 eeee) ee MMM (8 eM) ee −88°M, eee eeeee e 8 M MMMM eeee ee MMM (8.88 eM, 8.88 eeee, 8.8 eeeee). Meeeeeee eee eeeeeeeee eee 88 eee eeeeeeee ee eeeeeeeeee (Me8M/M8M). Meeeee eeeeeeeeeeeeee eeee eee eeeeeeeeeee eeeeeee (888 ee, 88%) ee e eeeeee eeeee. Meee eeeeeee eee eeeeeeeee ee MeMM (8 eM) eee eeee eeeeeee ee eeeeeeee eee eeeeeee ee eee eee 88 eee. Mee eeeeeeeeeeeeee eee eeeeeeeee ee MMM (MMMe8/MeMM 8:8). {Meee: eeee eee eeeeeeee ee [Me(MM)8(eeeee)] eeeeeeeee, eeeeeeeeeeeeee eee eeee eeeeee eeeee >8 e}. Meeeeeeeee eeeeeee Meeeee eeeeeee eee eeeeeeee eeeee eee eeeee eeeeeeeeeeeeee (eeeeee eee, MMMe8/MeMM 8:8) eeee ‌888‌ ee e eeeeeeee eeeeee eee; eeeee: 88 ee (88%, >88% ee, eeeeeeeeee eeeeeeeee eeeeeeeeee eeee eee Meeeee eeeee); [α]M −8.8 (e 8.88, MMMe8); 8M MMM (eeeeeee-e8, 888 MMe, δ): 8.88 (e, 8M, MeM), 8.88–8.88 (e, 8M), 8.88 (e, 8M, MMe), 8.88 (e, 8M, MMe), 8.88 (ee e, 8M), 8.88 (ee e, 8M, M = 88 Me), 8.88 (e, 8M), 8.88 (e, 8M), 8.8–8.8 (e, 8M), 8.8 (e, 8M).

References

Meeeeee Meeeeeeeeee

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