Categories: C-N Bond Formation > Synthesis of amides >
Transamidations
Recent Literature
A metal-free transamidation of tertiary amides bearing an N-electron-withdrawing
substituent provides primary amides in good yield in the presence of (NH4)2CO3 in
DMSO at 25 °C. In
addition, N-tosylated lactam derivatives afforded their corresponding N-tosylamido alkyl amide products.
J. Chen, Y. Xia, S. Lee,
Org. Lett., 2020, 22, 3504-3508.
In the presence of a catalytic amount of L-proline, transamidations of
carboxamides with amines were achieved under solvent-free conditions. The
reaction tolerates a wide range of amines.
S. N. Rao, D. C. Mohan, S. Admurthy, Org. Lett., 2013,
15, 1496-1499.
Sodium tert-butoxide mediates a transamidation of various N,N-dimethyl amides with primary amines to afford
the corresponding amides in moderate to good yields at room temperature under
solvent-free conditions. This protocol features a facile work-up procedure and
good functional group compatibility.
R. Zhang, J.-C. Zhang, W.-Y. Zhang, Y.-Q. He, H. Cheng, C. Chen, Y.-C. Gu, Synthesis, 2020, 52,
3286-3294.
[Ni(quin)2] catalyzes the N-formylation and N-acylation
of amines using N,N-dimethylformamide and N,N-dimethylacetamide in
the presence of imidazole in good yields. The protocol shows broad substrate
scope for aliphatic, aromatic, and heterocyclic amines.
R. B. Sonawane, N. K. Rasal, S. V. Jagtap, Org. Lett.,
2017, 19, 2078-2081.
A highly efficient transamidation of several primary, secondary, and tertiary
amides with aliphatic and aromatic amines (primary and secondary) is performed
in the presence of a 5 mol % concentration of different hydrated salts of Fe(III).
The methodology was also applied to urea and phthalimide to demonstrate its
versatility and wide substrate scope. A plausible mechanism explains the crucial
role of water.
L. Becerra-Figueroa , A. Ojeda-Porras, D. Gamba-Sánchez, J. Org. Chem., 2014,
79, 4544-4552.
The use of potassium tert-butoxide enables transamidation of primary
and tertiary amides with a range of aryl, heteroaryl, and aliphatic amines at
room temperature under transition-metal-free conditions to provide secondary
amides in high yields. Moreover, the reaction of cyclopropyl amine with tertiary
amides delivers enamides.
T. Ghosh, S. Jana, J. Dash,
Org. Lett., 2019, 21, 6690-6694.
A general, mild, and
highly chemoselective method for transamidation of unactivated tertiary amides
by a direct acyl N-C bond cleavage with non-nucleophilic amines is performed in the absence of transition metals and
operates under unusually mild reaction conditions. A direct amidation of abundant alkyl
esters affords amide bonds
with exquisite selectivity by acyl C-O bond cleavage.
G. Li, C.-L. Ji, X. Hong, M. Szostak, J. Am. Chem. Soc.,
2019,
141, 11161-11172.
A simple catalyst- and metal-free protocol enables a chemoselective
transamidation of activated secondary amides in ethanol as solvent under mild
conditions. A wide range of amines, amino acids, amino alcohols are tolerated in
this methodology. The transamidation reaction was successfully extended to water
as the medium as well.
R. Ramkumar, S. Chandrasekaran, Synthesis, 2019, 51,
921-932.
Nonplanar, electronically destabilized amides are powerful intermediates in
organic synthesis. A highly selective method for transamidation of common
secondary amides under mild, metal-free conditions relies on transient N-selective
functionalization to weaken amidic resonance. This procedure accomplishes
challenging transamidation of secondary amides under mild conditions.
Y. Liu, S. Shi, M. Achtenhagen, R. Liu, M. Szostak, Org. Lett.,
2017, 19, 1614-1617.
A facile, highly chemoselective transamidation of
N-Boc activated secondary amides proceeds
under exceedingly mild conditions in the absence of any additives. Because this
reaction is performed in the absence of metals, oxidants, or reductants, the
reaction tolerates a large number of useful functionalities.
Md. M. Rahman, G. Li, M. Szostak, J. Org. Chem., 2019, 84,
12091-12100.
CO2 promotes transamidation reactions as a traceless catalyst. In
the presence of catalytic amounts of CO2, transamidation reactions
were accelerated with primary, secondary, and tertiary amide donors. Various
amine nucleophiles including amino acid derivatives were tolerated. In
particular, N,O-dimethylhydroxyl amides (Weinreb amides) displayed a
distinct reactivity.
Y. Yang, J. Liu, F. S. Kamounah, G. Ciancaleoni, J. W. Lee, J. Org. Chem., 2021, 86,
16867-16881.
Formation of unstable but reactive acyl nitroso intermediates from Nα-protected
hydroxamic acids in the presence of iodine and DMSO enables an efficient and
straightforward coupling with an amino component to yield dipeptide esters.
M. Krishnamurthy, T. M. Vishwanatha, N. R. Panguluri, V. Panduranga, V. V.
Sureshbabu,
Synlett, 2015, 26, 2565-2569.
The reaction of N,N-dialkylformamide dimethyl acetal with primary amides
produces N'-acyl-N,N-dialkylformamidines as intermediates. In the
presence of certain Lewis acid additives efficient acyl transfer occurs,
providing new and useful methods for amide exchange such as transamidation.
T. A. Dineen, M. A. Zajac, A. G. Myers, J. Am. Chem. Soc., 2006,
128, 16406-16409.