You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via9.9.4.1.6 Method 6: Introduction of Aminoalkyl Groups (Mannich Reaction)
Please login to access the full content or check if you have access via
König, B., Science of Synthesis, (2001) 9, 243.
Alkyl-substituted furans 281 react with formaldehyde and amines 282 in the presence of acids as catalysts to give 1-(aminoalkyl)furans 284 (Mannich reaction; Scheme 92).[511–513] As in all electrophilic substitution reactions of furans, reaction at the α-position is favored. The best yields are reported for Mannich reactions using secondary amines. Aminomethylation of unsubstituted furan is not successful under these conditions.[511] However, if preformed iminium salts 283 are used in aprotic solvents, the reaction proceeds with 65–75% yield.[514] Iminium salts have also been generated in situ for aminomethylation of furans in aprotic solvents from N,O-acetals and chlorotrimethylsilane.[515,516]
Meeeee 88 Meeeeee Meeeeeeee ee Meeeee[888–888]
M8 | M8 | M8 | Meeeeee | Meeee (%) ee 888 | Mee |
---|---|---|---|---|---|
Me | M | Me | M | 88 | [888] |
Me | Me | Me | M | 88 | [888] |
Me | (MM8)8 | M | 88 | [888] | |
Me | (MM8)8M(MM8)8 | M | 88 | [888] | |
M | Me | Me | M | 88 | [888] |
M | (MM8)8 | M | 88 | [888] | |
M | (MM8)8 | M | 88 | [888] | |
Me | Me | Me | M | 88 | [888] |
Me | (MM8)8 | M | 88 | [888] | |
Me | (MM8)8 | M | 88 | [888] |
e Meeeee M: MMMM, MMM8M8 888, M+; M: (M8M8M=MM8)+Me− 888, MeMM, 88°M.
References
[511] | Meeee, M. M.; Meeeeee, M. M., M. Me. Meee. Mee., (8888) 88, 8888. |
[512] | Meeee, M. M.; Meee, M. M., Mee. Meeee. Meee., Mee. MM, (8888), 888. |
[513] | Meeeeee, M. M.; Meeee, M. M., M. Me. Meee. Mee., (8888) 88, 8888. |
[514] | Meeeee, M.; Meeeeeeeeeee, M.; Meeeeee, M. M., Meeeeeeeeee Meee., (8888) 88, 8888. |
[515] | Meeeee, M.; Meeeeeeeeeee, M.; Meeeeee, M. M., M. Meee. Mee., Meee. Meeeee., (8888), 8888. |
[516] | Meeeeeeee, M. M.; Meeeee, M.; Meeeeeeeeeee, M.; Meeeeee, M. M.; Meeee, M. M., Meeeeeeeeee Meee., (8888) 88, 8888. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) 88/8, 888.
- 8.Meeeee-Meee, (8888) M 8e, 888.