Science of Synthesis

Mikami, K.; Matsumoto, Y.; Shiono, T., Science of Synthesis, (2003) 2, 472.

Sodium cyclopentadienide derivatives are also used in the preparation of bis(cyclopentadienyl) complexes. Brintzinger has reported the synthesis of etheno-bridged ansa-titanocene derivatives (e.g., ‌43‌) by the McMurry reaction (‌Scheme 17‌).[‌110‌,‌111‌] The low yield of ‌43‌ (R1 = Me) is probably attributable to the preferred formation of the E-isomer in the McMurry coupling reaction; this is probably because the steric demand of the cyclopentadienyl ring is larger than that of the methyl substituent. The overall yield of 15% of the phenyl derivative [‌43‌, R1 = Ph (15%)] is higher than that of the methyl derivative [‌43‌, R1 = Me (8%)].

‌Meeeee 88‌ Me eeee-Mee(eeeeeeeeeeeeeeee)eeeeeeee(MM) Meeeeee eeee e Meeeee Meeeeeeeeeeeeeeee Meeeeeeeee eee Meeeeeee(MMM) Meeeeeee[‌888‌]

Meeeeeeeeeee Meeeeeeee

Meeeee (Meeeeeeeeeeeeeeeeeeeeee)–Meeeeeeeeeeeeee Meeeeee (‌88‌•MMM, M8 = Me); Meeeeee Meeeeeeee:[‌888‌]

M eeee ee MeMe (8.88 eeee) eee MeMMe (8.8 eee, 88.8 e) ee MMM (888 eM) eee eeeeeeee eee 88 e. Mee eeeeeee eee eeeeeee ee eeeee eee eeeeeeee ee Me8M (888 eM). Mee eeeee eee eeeeeeee eee, eeeeee eeee Me8M (888 eM), eee eeeee ee eeeee ee eeee ‌88‌•MMM (M8 = Me) ee e eeeeee eee-eeeeeeeee eeeee; eeeee: 88.8 e (88%); 8M MMM (MMMe8, δ): 8.88–8.88 (e, 8M), 8.88–8.88 (e, 8M), 8.88 (e, 8M), 8.88 (e, 8M), 8.88–8.88 (e, 8M), 8.88–8.88 (e, 8M).

Meeeeeee[(8,8-eeeeeeeeeeeeee)eee(η8-eeeeeeeeeeeeeeee)]eeeeeeee(MM) (‌88‌, M8 = Me); Meeeeee Meeeeeeee:[‌888‌]

MMMMMMM: Meeeeeeeeee eeee ee eeeee eeee eeeee eeeeeeeee eeeeeeee (M8M), eee, eeeeeeee ee ee eeeeee eeeee eeeeee ee eeee eeeeeeeeeee, ee ee eeeeee eeeeeeeeee eee eeeeee eeeeeeeeeee eeee eeeee!

M eeeeeeeeee ee MeMe8•8MMM (88.8 e, 88 eeee) eee M8M ee MMM (888 eM) eee eeeeeeee eee 8.8 e. Mee eeeeeee eee eeeeee ee ee, eee ‌88‌•MMM (M8 = Me; 8.8 e, 88 eeee) eee eeeee. Mee eeeeeee eee eeeeeeee eee 88 e, eeee eeeeee ee −88°M eee eeeeeee eeee MeMe8•8MMM (8 e, 8 eeee). Mee eeeeeee eee eeeeeee ee eeee ee ee, eeee eeeeeeee eee 8 e. Me eee eeee eeeeee ee −88°M eee 8 M ee MMe (8.8 eM) eee eeeee. Mee eeeeeee eee eeeeeee eee 8 e eeeee eee, eee eeee eeeeeeeeee ee eeeeeee. Mee eeeee eeeeeee eee eeeee ee ee MM8Me8 (888 eM) eee eee eeee eee eeeeee eeee 8 M ee MMe (8 × 88 eM). Mee eeeeeee eeeee eee eeeee (MeMM8) eee eeeeeeeeeeee. Meee eeeeeeee ‌88‌ (M8 = Me) eee eeeeeeee ee eeeeeeeeeee ee eeeee (888°M/8.88 Meee); eeeee: 8.8 e (8%); 8M MMM (MMMe8, δ): 8.88 (eeeeee e, M = 8.8 Me, 8M), 8.88 (eeeeee e, M = 8.8 Me, 8M), 8.88 (e, 8M) (eeeeee e = eeeeee eeeeeee).

References

Meeeeee Meeeeeeeeee

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