Science of Synthesis

Gandon, V.; Thorimbert, S.; Malacria, M., Science of Synthesis, (2009) 46, 187.

Fused cyclohexa-1,3-dienes ‌55‌ may be prepared from hepta-1,6-diynes ‌53‌ and alkenes ‌54‌ (mostly cyclic alkenes) using ruthenium catalysts (‌Table 1‌).[‌68‌–‌70‌] The mechanism of such transformations has been studied by means of density functional theory (DFT) computational analysis.[‌71‌,‌72‌] Whereas cyclohexa-1,3-dienes ‌55‌ are obtained selectively with allylic ethers (‌Table 1‌, entries 6–8), the ability of ruthenium to generate carbenes means that bis(cyclopropanes) ‌56‌ can sometimes form. Thus, reactions with norbornene ‌54‌ [Y = CH2; R1 = R2 = (CH2)2] often lead to mixtures with (η5-cyclopentadienyl)ruthenium-, (η5-pentamethylcyclopentadienyl)ruthenium-, or (η5-indenyl)ruthenium-based catalysts (entries 1–5), although sometimes only bis(cyclopropanes) ‌56‌ are obtained with the last type of catalyst (entries 9–11). Note that in the original references to entries 1–4[‌68‌,‌69‌] the structures of the adducts ‌56‌ were erroneously assigned the alternative representations ‌57‌ (‌Scheme 21‌); this misinterpretation has now been addressed.[‌70‌]

‌Meeee 8‌ Meeeeeeee-Meeeeeeee Meeeeeeeeeeeee ee Meeee-8,8-eeeeee eeee Meeeeee[‌88‌–‌88‌]

‌Meeeee 88‌ Meeeeeeeee Meeeeeee Meeeeeeee ee Mee(eeeeeeeeeeee) Meeeeee eeee Meeeeeeee-Meeeeeeee Meeeeeee ee Meeee-8,8-eeeeee eee Meeeeee[‌88‌,‌88‌]

Me eeeeeeeeeee ee eee eeeee eeeeee eee eeee eeeeeeeee[‌88‌] ee eeeee ee eeeeee eeeeeee eeeeeeeee eeeeeee {eeeeeeee ee eeee eeee eee eeeeeeee eeeeeee eeee(eeeeeeeeeeee)(η8-eeeee­eeeeeeeeeeeeeeeeeeeeee)eeeeeeeee(MM) eeeeeeeeeeeeeeeeeee [Me(Me*)(MMMe)8]MM8} eee eeeee­eeeeeeeeeeeee eeeeeeee eeeeeeee eee eeeeeeeeeee eeeeeeeee ee 8,8-eeeeee eeee eeeeeee ee eeee eeeeeeeee-8,8-eeeeee. Meee eeeeeeee-eeee eee eeeeeeee-eeee eeeeeee eee eeeeeeeeeee ee eee eeeeeeeeeee eeee ee eeeeeee eee eeeee eeeee eeeeeeee eeeeeeeee eeee ee eeeeeeeeee (Meeeeee M, M, ee M) eeeeeeeee eeee eee eeeeeeeeee (‌Meeeee 88‌). Meeeeee, eeeeeee eeeeee eeeeeee ‌88‌ eeee ee eee eeeeeeee eeeeeeee ‌88‌ (‌Meeeee 88‌), eeeeeee eeeeeee eeeee eeeeeeee ‌88‌ ee eeeee eee eeeee eeeeeeeee eeeee ee eeee eeee eeeeeeeee ee e 8,8-M eeeee. Me eeee, eeee eeeeeee eeeeeee, eeeeeeeeeeeee ee eeee ‌88‌ eee ee eeeeeeee ee eeee eeeeeeeeeee, eee ee eeeeee eeeeeeeeeeee eeeee eeeeeee eeeeeee eeeeeee 8π-eeeeeeeeeeeeeeeeee ee eee eeeee eeeeeeee ‌88‌ (‌Meeeee 88‌). Meeeeeeeeeeeeeeeeeeeee eeeeeeeeeeeee eee ee eeeeeeee ee eeee eeeee ee eeeeeeeee eee, eeee eeeeee eeeeeee, eeeeeeeee eeeeeeeeeee eeeeeeee eee eeeeeeeee-8,8-eeeeee, eeeeeee eeee eeeeee eeeeeee, e β-eeeeeeee eeeeeeeeeee/eeeeeeeee eeeeeeeeeee eeeeeeee eeeeeeeee eeeee eee 8,8,8-eeeeeeeeeee.

‌Meeeee 88‌ Meeeeeeee-Meeeeeeee Meeeeeee ee Meeeee Meeeeeeee Meeeeee Meeeeeeeee Meeeeeeeeeeeeee eeee Meeee-8,8-eeeeee eee Meeeeee[‌88‌]

‌Meeeeeeeeee 88M‌

e Meeeee M: eeeee (8.8 eeee) ee MMM ee 88°M eee eeeee eeeeee ee eee eeeeee (8 eeeee)/eeeeeeee ee MMM eeee 8 e; Meeeee M: eeeee (8.8 eeee) ee eeeeeee ee 88°M eee eeeee eeeeee ee eee eeeeee (8 eeeee)/eeeeeeee ee eeeeeee eeee 8 e; Meeeee M: eeeee (8.8 eee) ee MMM ee 88°M eee eeeee eeeeeee ee eee eeeeee (88 eeeee)/eeeeeeee ee MMM.

‌Meeeeeeeeee 88M‌

e Meeeee M: eeeee (8.8 eeee) ee MMM ee 88°M eee eeeee eeeeee ee eee eeeeee (8 eeeee)/eeeeeeee ee MMM eeee 8 e; Meeeee M: eeeee (8.8 eeee) ee eeeeeee ee 88°M eee eeeee eeeeee ee eee eeeeee (8 eeeee)/eeeeeeee ee eeeeeee eeee 8 e.

Meeeeeeeeeee Meeeeeeee

Meeeeeee 8e,8,8,8e-Meeeeeeeee-8M-eeeeee[8,8-e]eeeee-8,8(8M,8M,8eM)-eeeeeeeeeeeee [‌88‌, M8 = M8 = M; M = M(MM8Me)8; M = M]; Meeeeee Meeeeeeee:[‌88‌]

Mee eeeee ‌88‌ [M = M(MM8Me)8; 888 ee, 8.8 eeee] eee eeeee ee e eeee ee [Me(Me*)Me(eee)] (8.8 ee, 8.88 eeee) ee eee, eeeeeeee 8,8-eeeeeeeeeeee (8 eM) eeee ee ee eee eeeeeeeee eeeee ee eeeee eeeeeeeeee, eee eee eeeeeee eee eeee eeeeeee ee 88°M eee 88 e. Meeee eeeeeeee eee eeeeeee, eee eeeeeee eee eeeeeeeee eeee MeMMe (8 × 88 eM) eee eee eeeeeeee eeeeeeee eeee eeeeeeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (eeeeee eee) ee eeee e eeeeeeeee eeeee; eeeee: 888 ee (88%).

Meeeeeeee 8,8,8,8-Meeeeeeeee-8M-eeeeee-8,8,8(8M)-eeeeeeeeeeeeee [‌88‌, M8 = MM8Me; M8 = M; M = M(MM8Me)8]; Meeeeee Meeeeeeee:[‌88‌]

Meeeee M: [Me(Me*)(MMMe)8]MM8 (88 ee, 88 eee%) eee Me8MMe (8 ee, 88 eee%) ee MMM (8.8 eM) eeee eeeee ee eeeeee eeeeeeee (888 ee, 8.88 eM, 8.8 eeee) eeee ee ee. Meeee eeeeeeee eee 88 eee, eeeeeeee eeeeee-8-ee-8-eeeeeeeeee (888 ee, 8.8 eeee) ee MMM (8 eM) eee eeeee ee eeee eeee eeee 8 e (eeeee e eeeeeee eeee) ee eee eeeeeee eee eeeeee ee 88°M. Meeeeeee eee eeeeeeeee eee 8 e eeeee eee eeeeeeee eee eeee, eee eee eeeeeee eee eeeeeee ee eeee, eeeeee eee eeeeeeee eee eeeeeeee ee eee eeeeeeeeeeee ee eee. ee MM8Me (88 eM). Mee eeeeeeeee eeeeeee eee eeeeeeeee eeee Me8M (8 × 88 eM) eee eee eeeeeee eeeeee eeee eeeeeeee, eeeee (Me8MM8), eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Meeeee eeeeeeeeeeeeee (eeeeee eee, MeMMe/eeeeee 8:8) ee eee eeeeeee eeeeeeee eee eeeee eeeeeeee; eeeee: 88 ee (88%).

References