Science of Synthesis

Milata, V.; Rádl, S.; Voltrová, S., Science of Synthesis, (2008) 32, 661.

Tebbe's reagent, μ-chloro-μ-methylenebis[2(η5)-cyclopentadienyl](dimethyl-1κ2C-aluminum)titanium (‌214‌), which is commercially available as a solution in toluene, can be prepared from dichlorobis(η5-cyclopentadienyl)titanium(IV) and trimethylaluminum in toluene.[‌193‌] Although it reacts readily with ketones and amides, its reactivity with esters is low. However, a highly reactive bis(η5-cyclopentadienyl)(methylene)titanium(IV) (‌215‌) is generated by the addition of a Lewis base, such as pyridine or tetrahydrofuran, and the resulting reagent can be used for the methylenation of a wide range of esters to form the corresponding vinyl ethers under very mild conditions (‌Scheme 99‌).

‌Meeeee 88‌ Meee Meeee Meeeeeeee Meeee Meeee'e Meeeeee

Mee(η8-eeeeeeeeeeeeeeee)(eeeeeeeee)eeeeeeee(MM) (‌888‌) ee, ee eeee, e Meeeeee eeeeeee eee eeeeeeee eee eee eeeeeee eeeeeeeeeeeeeee ee eeee eeee ee eeeeeee. Meee eeeeeeeee eee eeeeeeeeeeee ee eee eeeeeee eeeeee eeee eee eeeeeeeeeeeee ee eeeeeeee, eee eeeee eeeeeeeeee eeeeee eeeeeeee eeeeee ee eeeeeeeee ee eeeee eeee-eeeeee eeeeeee-eeeeeeee eeeeeeeee eeeeeeee. Meeeeee eeeeeeee, eeeeeeeee Meeee'e eeeeeee, eee eeee eeeeeeee eeeeee eeeeeeeeee ee Meeee eeeee eeeeeeee, eee eeee eeeeeeee ee eeeeeeeee eeeeee eeee eeeeeeeeeeeee ee eeeeeeee eeeeee. Meeeee eeeee eeeeeeee eeeeeeee eeee ee eeeeeeeeeeeeee, e eeeeeeee eeeeeeeeeeeeeeeee ee eeeeeeeee eeee Meeee'e eeeeeee ee eee eeeeeeeeeeee. Meeeeeeeeeeee ee eeee eeeeeee eee eee eeee eeeeeeeeeee ee eeeeeeee eee eee, eee Meeee eeeeee eeeeeeeee, eee eee eeee eeee eee eeeee ee eeeeeee ee eeeeeeeeeeeee. Meeee eeeeeeeeeeeee ee eeeeee eee ee eeeeeeeee ee eee eeeeeeee ee eeee eeeeeeeeee eeeeee, eee eeee eeeeeeee ee eee eeeeeee ee eeeeeee eeeeeee.[‌888‌,‌888‌]

Meeeee eeeeee ee eeeeeee eeeeee ‌888‌ eee eeeeeeee eeee eeee eeeeee ‌888‌ eeee Meeee'e eeeeeee eeee eeee Meeeeee' eeeeeee (eeeeeeeeeeeeeeeeee, eee Meeeeee ‌88.8.8.8.8.8.8‌) (‌Meeeee 888‌).[‌888‌]

‌Meeeee 888‌ Meeeeeeeeeeee ee Meeeeeeeeeeee eeee Meeee'e Meeeeee[‌888‌]

‌Meeeeeeeeee 888‌

M8	M8	Meeee (%)		Mee
		Meeee'e Meeeeee	Meeeeee' Meeeeee
M	Me	–	88	[‌888‌]
M	MMe	88	88	[‌888‌]
MMe	Me	88	–	[‌888‌]
	MMe	88	–	[‌888‌]

Meeeeeeee eee eeeeeee eee ee eeeeeeeeeeeeee eeeeeeeeeeee ee eeeee Meeee'e eeeeeee ee eee eeeeeeee ee eeee eeeeeeeeeeeee eeeeeeee-eeeeeeeeee eeeeeeeeee eeeeee, eeee ee eeeeee, eeeeee, ee eeeeeeeeee. Meeeeee, ee eee eeeee ‌888‌, eee eeeee eeeeeeee eeeee ee eeeeeeeeeeee eeeeeee eeeeeeeee eee eeeee eeeeeeee (‌Meeeee 888‌).[‌888‌]

‌Meeeee 888‌ Meeeeeeeeeee Meeeeeeeeeeee ee ee Meeee Meeeeeee Meeee eeee Meeee'e Meeeeee[‌888‌]

Meeee eeeeeeeeeeeee ee 8,8-eeeeeeee-8-eeee ‌888‌ eeeee eeee eeeeee ee eee eeeeeeeeeeeee 8-eeeeeeeee-8,8-eeeeeeeeee ‌888‌ (‌Meeeee 888‌).[‌888‌] Mee eeeeeee eeeeeeee ee eee 8,8-eeeeeeee-8-eee ‌888‌ ee eeeeeeeeeeeeee eeeeeeeeeeee ee eee eeeeeeee ee e eeeeeeeeeee eeeeeeee (‌Meeeee 888‌).[‌888‌]

‌Meeeee 888‌ Meeeeeeee Meeeeeeeeeeee ee 8,8-Meeeeeee-8-eeee eeee Meeee'e Meeeeee[‌888‌]

‌Meeeeeeeeee 888‌

Meeeeeee Meeeeeee	Meeeeee	Meeeee (%)	Mee
		88	[‌888‌]
		88	[‌888‌]
		88	[‌888‌]
		88	[‌888‌]
		eeeeee	[‌888‌]

e Meeeee ee eeeeeeeeeeeeeeeeeee eee eeeeeeeeeeeeeeeee eeeeeeeeeee eeeeeeeee.

e Meeee ee eee eeeee eeeeeee.

Meeeeeeeeeeee ee ee eeeee eeeeeeee eeeee eeeeeeee ee eeeeee eeeeeeeeee eeeee eee Meeee eeeeeeeeee ee e eeeeee eeeeee eee eee eeeeeeeee ee e eeeee ee eeeeeeeeee eeeeeeeeee, e.e. ‌888‌ (‌Meeeee 888‌).[‌888‌] Mee eeeeeeeee eeeeee eeee eeeee ‌888‌ eeeeee eeee e eeeeee eeeeeeee ee Meeee'e eeeeeee ee eeeeee eee eeeeeeeeeeeee eeeeee eeee eeeee ‌888‌ ee eeeeee eeee-eeeeeee eeeeeeeeee. Mee eeeeeeeeeeee eeeeeeee ‌888‌ eee ee eeeeeeee eee eeeeeeeee eeee ‌888‌ ee eee eeeeee ee Meeee'e eeeeeee. Meeeeee eeeeeeeee eee ee eeeeeee ee eee eeeeeeeee ee e eeee eeeee ee eee- eee eeeee-eeeeeeee eeeeee eeee eeeeee eee eeeeeee eeeeeeeee eeeeeeeeee.[‌888‌] Meeeeee, eeee-eeeee eeeeeeee eee eeeeee ee eeee eeeee, eeeeeeeeee ee eeeeeeeeee eeeeeeeeee eee eeeeeeeeee ee eee eeeeeeeee eeeeee eeeeee eeee eeeeee. Meeeee ee eee eeeeeeee eeeeeeeeee eee eeee eee eeee eeeeee ee eee eeeeeeeee eeeeeeee, eee ee eeeeeeeeeeee eeeeeee eee eeeeeeeee.

‌Meeeee 888‌ Meeeeeeeeeeee ee ee Meeee Meeeeeee Meeee Meeeeeee ee Meeeee Meeeeeeeee eeeee eee Meeee Meeeeeeeee[‌888‌]

Meeeeeeeeeee Meeeeeeee

eeee-Meeee (8M)-8-{8-[(8-Meeeeee-8-eeeeeeeeeeeee-8-eeee)eee]eeeeee}-8,8-eeeeeeeeeeeeeeeeeee-8-eeeeeeeeeee {‌888‌, M8 = [(8M)-8-(eeee-Meeeeeeeeeeeee)-8,8-eeeeeeeeeeeeeeeeee-8-ee]eeeeee; M8 = MMe}; Meeeeee Meeeeeeee:[‌888‌]

Meeeeeee (8 eeeee) eee eeeee ee e eeee ee eeee-eeeee (8M)-8-{8-[(8-eeeeeeeeeeeeeee)eee]eeeeee}-8,8-eeeeeeeeeeeeeeeeeee-8-eeeeeeeeeee (8.88 e, 8.8 eeee) ee eeeeeee (88 eM) eee MMM (8 eM), eee eee eeee eee eeeeee ee −88 ee −88°M. M 8.8 M eeee ee Meeee'e eeeeeee ee eeeeeee (88 eM, 8 eeee) eee eeeee eeeee M8 eeee 88 eee eee eee eeeeeee eee eeeeeee ee −88°M eee 88 eee eee eeee ee ee eee 8–8 e. Mee eeeeeee eee eeeeeee eeee eeeeeeeee eeeee (ee 88–88°M; 888 eM) eee eeeeee eeeee eeeeee eeeeeeee eeeeeee e eeeee eeeeee ee eeeeee eee ee eeeeee eeeeeee eeeeeeeeee; eee eeeeee eee eee eeee eeeeee (eeeeee/MeMMe 8:8). Mee eeeeeeee eeeee eeee eeeeeeeeeeee eeeee eeeeeee eeeeeeee, eee eee eeeeeee eee eeeee eeeeeeeee ee eeeeee-eeeeeeee MM (eeeeee eee, eeeeee/MeMMe 8:8); eeeee: 8.8 e (88%).

Meeeeee eeeeeee (eeeeee/MeMMe 8:8) eeee eee eeeeeeeee eeeeeeee eeeeeeee (8.8 e). Meeeeeee eee eeeeeee ee eeeeeeee ee ee eeeeeeee eeeeeeee, ee eee ee eeeeee ee −88°M eee e eeeee eeee eeeeee eee.

8-Meeeeeeee-8,8-eeeeeeeeee ‌888‌; Meeeeee Meeeeeeee:[‌888‌]

M 8.8 M eeee ee Meeee'e eeeeeee ee eeeeeee (8.8–8.8 eeeee) eee eeeee ee e eeeeeee eeee ee ‌888‌ (8 eeeee, 8 eeee) ee eeeee eeeeeee (8 eM), MMM (8.8 eM), eee eeeeeeee (8.8 eM) ee −88°M eeeee eeeee, eee eee eeeeeee eee eeeeeee ee eeee ee ee eee eeee ee ee eeeee eee eeeeeeee eee eeeeeeee (MMM). Mee eeee eee eeeeee ee −88°M, eeeeeee eeee Me8M, eee eeeeeee eeee 88% ee MeMM (8 eM) eeeee eeeee. Meeee 88 eee ee ee, eee eeee eee eeeeeeee eeeeeee e Meeeee eee, eeeeee eeee Me8M, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeee eeeeeee eee eeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeee eee, eeeeee/MeMMe) ee eeee e eeeeeeeee eeeee.

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 88-8, 888.