Science of Synthesis

Petasis, N. A., Science of Synthesis, (2010) 47, 177.

Bis(η5-cyclopentadienyl)dimethyltitanium(IV) (‌37‌, dimethyltitanocene, also known as the Petasis reagent) is easily prepared by the reaction of dichlorobis(η5-cyclopentadienyl)titanium(IV) (‌11‌, titanocene dichloride) with 2 equivalents of methyllithium[‌56‌] or methylmagnesium chloride.[‌57‌–‌59‌] It is an effective reagent for the methylenation of a variety of carbonyl compounds to give alkenes[‌60‌] upon heating to 60–80°C (‌Scheme 10‌).[‌1‌–‌7‌,‌57‌–‌67‌] {See also Science of Synthesis, Vol. 32 [X—Ene—X (X = F, Cl, Br, I, O, S, Se, Te, N, P), Ene—Hal, and Ene—O Compounds (Section ‌32.5.3.1.4.4.2‌32.5.3.1.4.4.2)].}

Mee Meeeeee eeeeeee ‌88‌ eee ee eeeeeeee ee eeeeeee eeeeee eeeeeeee ee eeeeee eeeee ee eee eeeeeeee eeeeeee, eeeeeeeeee eeee eeeeeee eeeee, eee eeeeeee ee eee eeeeeee eeeeeee eeeeeee. Meeeeee, ee eeeeeeeeee eeeeeee ee ee eeeeeeeeeeeee eee eeeeeeeeee eeeeeee eeee eeeeeeee ee eeee (>88°M) ee eeeee. Me ee eeeeeee eeeeee ee eeeeeee eeeeeeeeeee ee eee eee, eee eee ee eeeeee eee eeeee eee eeeeee ee 8°M ee eee eeee eeeee e eeeeeeee eeeeeeeeee ee e eeeeeeee ee eeeeeeeeeeeeeee ee eeeeeee, eeeee eee ee eeee eeeeeeee ee eeeeeeeeeeeee eeeeeeeee. Meeeeeeeeeeee, ee eeeee ee eeeee eeeeeeeee eeeeeee eeeeeeeeeeeee, e eeeeeee eeeeeeee eee ee eeeeeeee eeeeeee eeeee eeeeeeeee ee eee eeeeeeeeeee eeeeeee eeeee eeeeeeeeeeeeeee eeeeeeee ee eeeeeee, eeeeeeee ee eeeeeee eeeeee ee eeeeee eeee eeeeeeeeee, eeeeeeeeee eeeeee, eee eeeeeeeeeeeee ee eee eeeeeeee ee eeeee 8 M ee eeeeeee.[‌88‌–‌88‌]

Meeeee eee Meeee eeeeeee ‌88‌ (eee ‌Meeeee 8‌, Meeeeee ‌88.8.8.8.8‌), eee Meeeeee eeeeeee ‌88‌ ee eeeeeeeeeeeee, eee Meeee eeeeee, eee eeeeeeeeee eeeeee ee eee eee eeeee. Me ee eeee eeee ee eeeeeeee eeeeeeeeee. Mee eeeee eeeeeee, ee eeeeeeee ee eeeee eeeeee ee eeeeeee, ee ee e eeee eeeeeeeeee eee eeeeeeeee eeeeeee eee eeeeeeee eeeeeeeeeeeee eeeeeeeee, eee ee eeee eee eeee eeeeeeee ee eeeee (eeee) eeeee eeeeeeeeeeee eee eee eeeeeeeee ee eeeeeeeeeeeeee eeeeeeeeeeeee.[‌88‌–‌88‌] Mee eeeee eeeee-eeeee eeeeeeeeee, eeeeeeeeeee ee eee eeeeeee ee eeeeeeeee ee eeeeeee, ee eeeee ee ee eeeeeeeeeeee, eee eeeeeee eeeeeee ee eee eeeeeee eeeeeee eeeee eeeeeeeee ee eee eeeeeeeeeee eeeeeeee. Mee eeeeeeeee ee eeee eeeeeeeeeeeee eeeeeee[‌8‌,‌88‌] ee eeeeeee ee eeee ee eee Meeee eeeeeee, ee eeee ee eeeeeeeeee eeeeeeee eee eeeeeeeee eeeeeeeee eeeeeeee eeeeeee ‌88‌, eeeee eeeeee eeee eee eeeeeeee eeeeeeee ee eeee e eeeeeeee-eeeeeeeeee eeeeeee eeeeeeeeee ‌88‌, eeeee ee eeee eeeee ee eee eeeeee eeeeeee. Meeeeeeeeeee eeeeeeee eee eee eeeeeeeee ee ‌88‌ eeee ‌88‌ eee eeee eeeeeeee ee eeee eeeeeeeeeeee.[‌88‌]

Mee eeee eeeeeeee eeeeeeeee ee eee eeeeeeeeeeeee eeeeeee ee eee(η8-eeeeeeeeeeeeeeee)eeeeeeee(MM) eeeee (eeeeeeeeee eeeee), eeeee eee ee eeee ee eeeeeeee eeeeee eee eeeeeeee ee eeeeeeeeeeeeeee ee eeee ee eee eeeeeee. Meee eeeeeeee eeeeeeeee eee ee eeeeeeee ee eeeeeeee eee eeeeeeee eeeeeee eeee eeeeeeeeeeeeeeeeeeeee eee eeeeeeee, eeeeeeee ee eeeeeeeeeeeee eee eeeeeee eeeeeeeee.[‌88‌] Meee eeeeeee ee eeee ee eee eeeeeee, eee eeeeeeee eeeee eeeeeee eeeeee eeee eee Meeeeee eeeeeee ee eeee ee eee-eeeeeee eeeeeeeeee eeeeeeee ‌88‌ (eeeeeeeee ee eeeeeee eeee eeeeeee eee eee ee 8 eeeeeeeeeee ee eee Meeeeee eeeeeee).[‌88‌,‌88‌] Meee eeeeeeeee eee eeee ee eeeeeeee ee eeeeeeeeeeeee, eeeeeeeeeeeeeee, eee eeeeeeee eeee eeeeeeeeeeee eeee ee eeeeeee ee eeeeeeeeee eeeeeeeeeee eeeeeeeeeee(η8-eeeeeeeeeeeeeeee)eeeeeeee(MM) (‌88‌).[‌88‌]

‌Meeeee 88‌ Meeeeeeee eee Meeeeeeeee ee eee Meeeeee Meeeeee[‌8‌–‌8‌,‌88‌–‌88‌]

Mee Meeeeee eeeeeee ee eeeeeeeee eee eee eeeeeeeeeeeee ee e eeee eeeee ee eeeeeeee eeeeeeeee eeeeeeeee eeeeeeeee, eeeeeee, eeeeee, eeeee eeeeee, eeeeeeee, eeeeee, eeeeeee, eeeeeeeeee, eeeeeeeeee, eeeeee, eeeeeeeeee, eee eeeeeeeeeee.[‌8‌–‌8‌,‌88‌–‌88‌] Me e eeeeee ee eee eeeeeeee eee eeeeeeeee eeeeee, eeee eeeeeee eee eee eeeeeeeee eeee ee eee ee eeeeeeee eeee eee eeee-eeeeeeeee ee eeee ee eeee-eeeeeeeee eeeeeeeee eee eeeeeeee. Meeeeee, ee ee eee eeeeeeee eee eeeeeeeeee eeee eee eeee eeeeeeeee ee eee eeeeeeeeeeee eeeeeeee ee eee eeeeeeee. Me e eeeeeee eeeeeeee, eee eeeeeeee eeeeeeeee ‌88‌ ee eeeeeeee eeee e eeeeeee ee eeeeeeeeeeeeeee eeeeeeee ee eee Meeeeee eeeeeee ‌88‌ (8–8 eeeee), eee eee eeeeeee ee eeeeee ee 88–88°M ee eee eeee ee eeee eee eeeeee ‌88‌. Meee eeeeeee eee eeee ee eeeeeeee eeeeeee eeeeeee eee eeee eee ee eeeeee ee eeeee eeeeee (‌Meeeee 88‌).[‌88‌] Mee eeeeeeeeee ee 8,8-eeeeeee-8M-8-eeeeeeeeee-8-eee eeee 8,8-eeeeeee-8-eeeeeeeee-8M-8-eeeeeeeeee ee eeee eeeeee eee eeee eeee eeeeeeee (‌Meeeee 88‌).

‌Meeeee 88‌ Meeeeeeeeeeee ee Meeeeeee Meeeeeeee[‌88‌]

‌Meeeeeeeeee 88‌

Mee eeeee ee eee eeeeeeeeeeeee eeeeeee eee ee eeeeeeee, eeeeeeeeeeee eee eeeee-eeeee eeeeeeeeeeee, ee eee eeeeeeee ee e eeeeeeee eeeee eeee ee 8-eeeeee-8-eeeeeeeeeeee-8-ee eeeeeee, eeeee eee ee eeeee ee eee eee(η8-eeeeeeeeeeeeeeee)eeeeeeeeeeeeeeee(MM) eeeeeeee eeeee ee eeeeeeeeeeeee.[‌88‌] Mee eeeeeeee ee eeeee eeeeeee ee eeeeeeeeeee(η8-eeeeeeeeeeeeeeee)eeeeeeee(MM) ee eee eeeeeee eeeee ee eee eeeeeeeeeeeee eeeeeeee eee eeee eeeeeee eee eeeee eee eeee eeeeeee eeeeeeee.[‌88‌] Me eeeeeeeeee eee eeeeeeee eeeeeeeeee eeee eee eee ee eeeeeeeee eee eeeeeeee eeeeeeee eeeeeeeee, eee eeeeeeeeeeeee eeeeeee eee eeee eeeeeeeeeeee eeeeeee ee e eeeee (888 ee) eeeee ee eee eeeeeeeeeeeee ee eee eeeee ‌88‌ ee eeee eee eeee eeeee ‌88‌ ee 88% eeeee. Meee eeeee eeee ee eee eeeee-ee eeeeeeeee ee eeeeeeeeee (‌Meeeee 88‌).[‌88‌,‌88‌,‌88‌] Meeeeeee ee e eeeeeee eeeee eeeee eeeeeeeeeeee eeeeeeeeee eeeeeeee ee eeeee eeeee (88%),[‌88‌] eeeee eee ee eee Meeee eeeeeee ‌88‌ ee eeee eeee eeeeeeeee, eeeeeee eee eeee eeeee ‌88‌ ee eeee 88% eeeee, eeeeeeeeee eee ee eee Meeee eeeeeee ee eee eeeeeee.[‌88‌]

‌Meeeee 88‌ Meeee-Meeee Meeeeeeeeeeee[‌88‌,‌88‌,‌88‌]

Me eeeeeeee ee eeeeeeee eee eee eeeeeeeeeeeee eeeeeee eeeee eeeeeeeeeeee eeeeeee, eee eee ee eeeeeeeee eeeeeeeeeee ee eeeeee eeeeeeeeeeee eee eeeeeeeeeeeee eeeeeee eee eeeeee ee eeee eeeeeeee, eeee ee eee eeeeeee ‌88‌, eeeee ee eeeeeeee ee eeeeeeeee eeeeeeeeeeeee ee eee eeee eeeeeeee eeeee eeeeeeee eeeee ee eee eeeeeeeeee ‌88‌ (‌Meeeee 88‌).[‌88‌]

‌Meeeee 88‌ Meeeeeeee-Meeeeeee Meeeeeeeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeeee

Mee(η8-eeeeeeeeeeeeeeee)eeeeeeeeeeeeeeee(MM) (‌88‌, Meeeeee Meeeeee):[‌88‌,‌88‌]

MMMMMMM: Meee eeeeeee ee eeeee ee eeeeeeeeeeee ee eee ee 88 °M, ee eee eeeee eeee eee Meeeeee eeeeeee eeeeeeeee e eeeee, eeeeeeeeee, eeeeeeeeeeeee eeeeeeeeeeeee eeee eeeeeeeee eeeeeee eee, eeeeeeeee ee e eeeee eeeeeeee ee eeeeeeee.

M 8.8 M eeee ee MeMe (88.8 eM, 88.8 eeee, 8.8 eeeee) eee eeeee eeeeeeee ee e eeeeeeeeee ee Me(Me)8Me8 (‌88‌; 88 e, 88.8 eeee) ee eeeee Me8M (888 eM) eeeeee ee ee eee eeee. Mee eeeeeee eee eeeeeee eee 8 e eeeee eee eeeee eee eeeeeeee eeee eeeee eeee Me eeee. Meeee eeee eeeeeeee ee eee eeeee (88 eM), eee eeeeee eeee eee eeeeeeeee eeee Me8M, eee eee eeeeeee eeeee eee eeeee (MeMM8), eeeeeeee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee ee 88–88°M (MMMMMMM: eeeee eeeeeeeeeeeee eee eeeee ee eee eeeeeeeeeee ee eeeeeee ee eeee eeeeee eee eeeeeeeeeeeee ee eee eeee. Me eee ee eeeeeeeee ee eeeeeee eee eeeeeeeeeee eeeeeeeeeee eeeee 88 °M, eee ee eeeeee eeeeee ee eee eeeeeeee ee eee eeeeeeee eeeeeeee ee ee eeeeeeeeeeee eeeee ee eeeeeee eeeeeeeeeeeee). Mee eeeeeeeee eeeeee eeeeee eeeeeeee eeee eeeeeee eeeee eeeee eeeeee eeee M8M8; eeeee: 8.88 e (88%). Mee eeeeeee ee eeeeee ee eeeee eeeeeeee ee M8M ee eee, eee ee ee eeeee eeeeeeeee eee eeeeeeeeee eeeeeee ee eee eeeee eeeee. Me eee ee eeeeee ee eee eeee ee −88°M ee e eeee (8.8 M) ee eeeeeee ee MMM eee eeeeeee eeeeee eeeeeee eeeeeeeeeee eeeeeeeeeeeee.

Meeeeee Meeeeeee ee Mee(η8-eeeeeeeeeeeeeeee)eeeeeeeeeeeeeeee(MM) (‌88‌, Meeeeee Meeeeee):[‌88‌,‌88‌,‌88‌]

MMMMMMM: Meee eeeeeee ee eeeee ee eeeeeeeeeeee ee eee ee 88 °M, ee eee eeeee eeee eee Meeeeee eeeeeee eeeeeeeee e eeeee, eeeeeeeeee, eeeeeeeeeeeee eeeeeeeeeeeee eeee eeeeeeeee eeeeeee eee, eeeeeeeee ee e eeeee eeeeeeee ee eeeeeeee.

Me(Me)8Me8 (‌88‌; 8.88 e, 88.8 eeee) eee eeeeeeee ee eeeeeee (88 eM) eeeee M8 eee eee eeeeeee eee eeeeee ee 8°M. M 8 M eeee ee MeMeMe ee Me8M (88 eM, 88 eeee, 8.8 eeeee) eee eeeee eeeeee eeee 88 eee, eeeeeee eee eeeeeeeeeee eeeee 88°M. Mee eeeeee eee eeeeeee ee 8–8°M eee 88 eee, eee eeee eee eeeeeeee eee eeeeeeee ee eeeeeee eee eeeeeee eeeeee 88 eee eeee eee-eeee 8% ee MM8Me (88 eM). Mee eeeeee eeee eeeeeeeee, eee eee eeeeeee eeeee eee eeeeee eeee M8M (8 × 88 eM) eee eeee eeeee (88 eM). Mee eeee eee eeeeeeee eeeeeee e eee ee MeMM8 eee eeee eeeeeeeeeeee eeeee eeeeeee eeeeeeee ee e eeeeee ee 88 eM. Mee eeee eee eeeeeee eeee eeeeeee (8 × 88 eM) ee eeeeee Me8M eee eeee eeeeeeeeeeee ee e eeeee eeee ee 8.88 e. 8M MMM eeeeeeee (eeeeeeeeeee ee eeeee eee eee eeeeeee eeeeee eeeee eee eee Me eeeeee) eeeeeeeee e 88.8 ee% eeee ee eee Meeeeee eeeeeee ee eeeeeee; eeeee: 8.88 e (88%).

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

Meeeeeeeeeee (‌88‌, M8 = M8 = Me; 8 eeee) eee eeeee ee e 8.8 M eeee ee eee Meeeeee eeeeeee ‌88‌ ee MMM (8 eM, 8 eeee), eee eee eeeeeee eee eeeeeee eeeee eeeee ee eee eeee ee 88°M. Meeee eee eeeeeeee eee eeeeeeee (8–88 e), eee eeeeeee eee eeeeeee eeee eeeeeeeee eeeee. Mee eeeeeeeee eeeeee-eeeeee eeeeeeeeeee eee eeeeeee ee eeeeeeeeee, eee eee eeeeeeee eee eeeeeeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (eeeeee eee ee eeeee eeeeeee, eeeeee); eeeee: 88%.

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

M 8.8 M eeee ee eee Meeeeee eeeeeee ‌88‌ ee eeeeeee (88 eM, 88 eeee) eee eeeee eeee eeeeeee eeeeeee [‌88‌, M8 = Me; M8 = M(MM8)88Me; 8.88 eM, 88 eeee], eee eeeeeee eee eeeeeee eeeee eeeee ee eee eeee ee 88°M eee 88 e, eee eee eeeeeeee ee eee eeeeeeee eee eeeeeeeee ee MMM [eeeeeee eeeee eeee eeeeeeee eeee MMM ee eee eeeeeee ee ee eeeeee eeeeeeeeeeee (88°M)]. Meeee eeeeeee ee ee, eee eeeeeee eee eeeeeeeeeeee ee eeeee eee-eeee ee eee eeeeeeee eeeeee eee eeee eeeeeee eeee eeeeeeeee eeeee (888 eM). Mee eeeeeeeee eeeeee eeeeeeeeee eee eeeeeee ee eeeeeee eeeeeeee eeeeeeeeeeeee, eee eeeeee-eeeeee eeeeeeeeeee eee eeeeeee ee eeeeeeeeee, eee eee eeeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeeeeeeeee eeeee eeeeee eeeeeeeeeeeeee (eeeee eeeeeee, eeeeeeeee eeeee/Me8M/Me8M 88:8:8.8) ee eeee e eeeeeeeee eee; eeeee: 8.88 e (88%).

(8M,8M)-8-Meeeee-8-({8-[8,8-eee(eeeeeeeeeeeeeee)eeeeee]eeeee}eee)-8-(8-eeeeeeeeeeee)eeeeeeeeee (‌88‌, Meeeeeeeee); Meeeeee Meeeeeeee:[‌88‌]

M eeee ee eee eeeee ‌88‌ (8.88 e, 8.8 eeee) ee MMM (88 eM) eee eeeeeee eeee e 8.8 M eeee ee eee Meeeeee eeeeeee ‌88‌ ee eeeeeee (88.8 eM, 88.8 eeee), eee eee eeeeeeeee eeeeeee eee eeeeeee ee ee eee eeee ee 88°M eee 88 e. Mee eeeeeee eee eeeeee eee eeeeeeeeeeee. Meeee eeeeeeeeeeeeee [eeeeee eee (888 e), eeeeeee/MM8Me8 8:8] eeeeeeee eee eeee eeeee ‌88‌ ee e eeeee, eeeee eeeee ee eeeeeeeeeeeeee (eMeMM); eeeee: 8.88 e (88%). Mee eeeeeeeeeee ee ‌88‌ eee eeeeeeeee ee eee 888-ee eeeee; eeeee: 88% [eeeeeeeeee: ‌88‌ (8.8 eeeee), ‌88‌ (8.88 eeeee), eeeeeee eeeeeeee (8.88 eeeee), eeeeeee, 88°M, 8.8 e].

eeee-Meeee 8-Meeeeeeeeeeeeeeeee (‌88‌); Meeeeee Meeeeeeee:[‌88‌]

eeee-Meeee eee(eeeeeeeeee)eeeeeee (‌88‌; 888 ee, 8.88 eeee) eee eeeeeee eeee e 8.88 M eeee ee eee Meeeeee eeeeeee ‌88‌ (8.88 e, 88.88 eeee, 8.8 eeeee) ee MMM/eeeeeee (88.8 eM) eeeee eeee-eeeeee eeeeeeeee eeeeeeeeeee (8 e, 888 M, 888°M, eeeeeeeeeee eeeeeeee). Mee eeee eee eeeeee ee ee, eee eee eeeeeee eee eeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeee eeeeeeeee eeeee e Meeeeeeee eeeeeeeee eeeeeeee eeee eee Me eeeeeeee ee eeee e eeeeeeeee eee; eeeee: 8.888 e (88%).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 8/8e, 888.