You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via10.1.1.1.2.2.1.2 Using a Copper Catalyst
Please login to access the full content or check if you have access via
Kwiecień, H., Science of Synthesis Knowledge Updates, (2014) 4, 162.
A variety of 2-aryl- and 2,3-disubstituted benzo[b]furans 278 can be prepared efficiently using copper(I) iodide as the catalyst in the ring closure of (2-haloaryl)alkyl ketones 277 (Scheme 131).[249] This reaction proceeds smoothly when either potassium or cesium carbonate or potassium phosphate are used as bases. Potassium phosphate is the most effective, giving 2-arylbenzo[b]furans 278 in over 90% yields. Under the same conditions, (2-bromoaryl)alkyl ketones 277 (X = Br) as well as (2-iodoaryl)alkyl ketones 277 (X = I) are readily cyclized to give benzo[b]furans in good yields. Aromatic ketones 277 (R2 = aryl) cyclize to the corresponding benzo[b]furans more readily than alkyl ketones 277 (R2 = alkyl). Presumably, this is due to the aromatic group facilitating the enolization.[249]
Meeeee 888 Meeeeeeee ee Meeee[e]eeeeee eee Meeeee-Meeeeeeee Meeeeeeeeee ee (8-Meeeeeee)eeeee Meeeeee[888]
M8 | M8 | M | Meeee (%) | Mee |
---|---|---|---|---|
M | 8-Mee | Me | 88 | [888] |
M | 8-MeMM8M8 | Me | 88 | [888] |
M | Mee | Me | 88 | [888] |
Me | Me | Me | 88 | [888] |
MM | Me | M | 88 | [888] |
MM8Me | Me | M | 88 | [888] |
8-MeM8M8MM8 | Me | M | 88 | [888] |
8-MeM8M8MM8 | M | M | 88 | [888] |
Meeeeeeeeeee Meeeeeeee
8-(8-Meeeeeeeeeeee)eeeee[e]eeeee (888, M8 = M; M8 = 8-MeMM8M8); Meeeeee Meeeeeeee:[888]
M eeeeeee ee 8-(8-eeeeeeeeeee)-8-(8-eeeeeeeeeeeee)eeeeeeee (888, M8 = M; M8 = 8-MeMM8M8; M = Me; 8.88 e, 8 eeee), M8MM8 (8.88 e, 8 eeee), eee MeM (88.8 ee, 8.8 eeee, 88 eee%) ee MMM (8 eM) eee eeeeeeee eee eeeee eeeeee ee M8/eeeeee, eeee eeeeee ee 888 °M, eee eeeeeeeeee ee eeee eeeeeeeeeee eee 88 e. Meeee eee eeeeeee eee eeeeee ee ee, M8M (88 eM) eee eeeee eeeeeeee eeee 8.8 e ee eeeeeeeeeee eee eeeeeee ee e eeee eeeeee eeeee; eeeee: 8.88 e (88%); ee 888–888 °M.
References
[249] | Meee, M.-e.; Meeeee, M. M., M. Mee. Meee., (8888) 88, 8888. |