Categories: Synthesis of N-Heterocycles > Lactams >
Synthesis of δ-lactams
Recent Literature
A quick, efficient, one-pot, BF3ˇOEt2-mediated reaction of
various substituted arenes with azido alkanoic acid chlorides affords
substituted N-aryl lactams in good to excellent yields at room
temperature.
D. Caturvedi, A. K. Chaturvedi, N. Mishra, V. Mishra, Synlett, 2012, 23,
2627-2630.
An Al(OTf)3-catalyzed cascade cyclization and ionic hydrogenation
reaction of nitrogen substituted ketoamides enables an efficient and versatile
synthesis of N-substituted lactams, pyrrolindinones, piperidones, and
structurally related heterocycles in good yields.
J. Qi, C. Sun, Y. Tian, X. Wang, G. Li, Q. Xiao, D. Yin, Org. Lett., 2014,
16, 190-192.
Ir catalysis achieves a lactam synthesis directly from lactones and amines via
aminolysis of lactone, N-alkylation of amine with hydroxyamide, and
intramolecular transamidation of aminoamide.
K. Kim, S. H. Hong, J. Org. Chem.,
2015,
80, 4152-4156.
In a metal-free, selective oxidation of cyclic secondary and tertiary amines for
the formation of lactams, molecular iodine facilitates both chemoselective and
regioselective oxidation of C-H bonds directly adjacent to a cyclic amine. The
reaction offers mild conditions, functional group tolerance, and a broad
substrate scope.
R. J. Griffiths, G. A. Burley, E. P. A. Talbot, Org. Lett.,
2017, 19, 870-873.
A palladium-catalyzed intramolecular hydroamidation of amidoalkynes in
1,4-dioxane at 100°C gives lactams in good yields.
N. T. Patil, Z. Huo, G. B. Bajracharya, Y. Yamamoto, J. Org. Chem., 2006, 71, 3612-3614.
Alkylation of the aza-enolate of valerolactim methyl ether with electrophiles
affords α-alkyl lactims. Subsequent mild, acidic hydrolysation gives the
corresponding α-alkyl-δ-amino esters hydrochloride salts. Neutralisation of
these salts with base results in smooth intramolecular cyclisation to afford
α-alkyl lactams in excellent yield.
P. J. M. Taylor, S. D. Bull, P. C. Andrews, Synlett,
2006, 1347-1350.
A very efficient NHC-catalyzed ring expansion reaction cleanly furnishes five-
and six-membered N-Ts and N-Bn lactams, without the need for
further purification. The stoichiometric base is responsible for deprotonation
of the triazolium precatalyst and activation of the nitrogen leaving group
through hydrogen bonding.
K. Thai, L. Wang, T. Dudding, F. Bilodeau, M. Gravel, Org. Lett., 2010,
12, 5708-5711.
N-Alkenyl β-ketoamides undergo a mild cyclization in the presence of
Au[P(t-Bu)2(o-biphenyl)]Cl and AgOTf with excellent regioselectivities and
yields. The reaction provides an efficient method to prepare highly substituted
lactams.
C.-Y. Zhou, C.-M. Che, J. Am. Chem. Soc., 2007,
129, 5828-5829.
A very simple method for the α-arylation of N-protected
2-piperidinones in high yield is described. Key factors are the use of ZnCl2 and
Pd(dba)2 and the nature of the base.
A. de Filippis, D. G. Pardo, J. Cossy, Tetrahedron, 2004,
60,
9757-9767.
An intramolecular vinylation of various iodoenamides using CuI as the
catalyst and N,N'-dimethylethylenediamine as the ligand led to five-
to seven-membered lactams in moderate to excellent yields.
T. Hu, C. Li, Org. Lett., 2005, 7, 2035-2038.
A direct Pd-catalyzed arylation reaction for the intramolecular formation of
biaryl compounds using a novel phosphine ligand offers enhanced catalytic
activity for transformations of previously unreactive substrates.
L.-C. Campeau, M. Parisien, M. Leblanc, K. Fagnou, J. Am. Chem. Soc.,
2004, 126, 9186-9187.