You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via46.5.2.2.6 Variation 6: Iridium-Catalyzed Cycloaddition
Please login to access the full content or check if you have access via
Gandon, V.; Thorimbert, S.; Malacria, M., Science of Synthesis, (2009) 46, 201.
Only a few methods have been reported for the formation of cyclohexa-1,3-dienes by means of iridium-catalyzed [2 + 2 + 2] cycloadditions. Nevertheless, these reactions are efficient, even when carried out at very low catalyst loadings, especially for cocyclizations between 1,6-enynes 95 and alkynes to afford bicyclic dienes 96 (Scheme 34).[78] However, byproducts 97 and 98, resulting from the formal metathesis of the enyne, are to be expected and the extent of this competition depends upon the type of diphosphine ligand present in the catalyst. Thus, with the 1,1′-bis(diphenylphosphino)ferrocene ligand enyne metathesis prevails, whereas with 1,2-bis(diphenylphosphino)ethane cycloaddition may predominate.
Meeeee 88 Meeeeee-Meeeeeeee [8 + 8 + 8] Meeeeeeeeeeeee eeeeeee 8,8-Meeeee eee Meeeeee[88]
| M8 | M8 | Meeeee | Meee (e) | Meeee (%) ee 88 |
Meeee [(M)-88/(M)-88/(M)-88)] | Meeee (%) ee 88/88 |
Mee |
|---|---|---|---|---|---|---|---|
| M | Me | eeee | 8 | 88 | 88 eeee | 8 | [88] |
| M | Me | eeee | 8 | 88 | 88:8:8 | 88 | [88] |
| M | Me | eeee | 88 | 88 | 88 eeee | 88 | [88] |
| M | Me | eeee | 8 | 8 | 88:8:8 | 88 | [88] |
| M | Me | eeee | 8 | 8 | 88:8:8 | 88 | [88] |
| M | Me | eeee | 8 | 88 | 88 eeee | 88 | [88] |
| M | Me | eeee | 88 | 88 | 88 eeee | 88 | [88] |
| Me | Me | eeee | 8 | 88 | 88:8:88 | 88 | [88] |
| Me | Me | eeee | 8 | 88 | 88:88:88 | 88 | [88] |
Mee eeeeeeeeeeeee ee 8,8-eeeeee eeee ee eee eeeeeee 88 eeee eeeeeee ee eeee eeee eeeeeeeee ee eeeeeeeeee. Mee eeeeeeee, eeee 8,8-eeeeeeeeeeee, eee eeeeeeee eeeeeeeeeeeeee 888 ee eeeeeeeeeee ee e eeeeeeeeeeeeeeeee eeeeeee (888). Meee eeeee eeeeee, eeee ee 8,8-eeeeeeeeeeee ee eeeee eeeee eeeee, eee eeeeeeee eeeeeeeeeeeeeee eee eee eeeeeeee; eeeeeee, eee eeeeeeeeee eeeeeeeeeeee 888 ee 888 eee 888 eee eeeeeeee (Meeeee 88).[888]
Meeeee 88 Meeeeee-Meeeeeeee [8 + 8 + 8] Meeeeeeeeeeeee eeeeeee 8,8-Meeeee eee Meeeeee[888]
Meeeeeeeeeee Meeeeeeee
Meeeeee 8,8-Meeeeee-8-eeeeee-8,8,8e,8-eeeeeeeeee-8M-eeeeee-8,8-eeeeeeeeeeeee (88, M8 = M; M8 = Me); Meeeeee Meeeeeeee:[88]
M eeeee eee eeeeeee eeee [Me8Me8(eee)8] (88.8 ee, 8.888 eeee) eee eeee (88.8 ee, 8.888 eeee). Mee eeeee eee eeee eeeeeeeee, eee eeeeeeee eeee eeeee, eeeeee eeeeeee (8 eM) eee eee-8-eee (888 ee, 8.8 eeee) eeee eeeeeeeeee eeee eeeeeeee, eeeeeeee ee eee eeeee 88 (M8 = M; 888 ee, 8.88 eeee). Mee eeeeeeeee eeeeeee eee eeeeeee eee eeeeeeee eee 8 e, eeeee ee eee eeeeeee ee eee eeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, MeMMe/eeeeee 8:88) ee eeeeee eee eeeee eeeeeeee ee e eeeeeeeee eee; eeeee: 888 ee (88%); eeeeeeee eeee e eeeeeee ee 88 eee 88 (eeee e eeeeeeeee eee); eeeee: 88 ee (88%).
References
| [78] | Meeeee, M.; Meeee, M.; Meee, M.; Meeeeeee, M., Mee. Meee., (8888) 8, 8888. |
| [105] | Meeeee, M.; Meeeee, M.; Mee, M.; Meeeee, M.; Meeeeeee, M., M. Mee. Meee., (8888) 88, 888. |
Return to Top