Categories: Synthesis of N-Heterocycles >
Synthesis of indolizines
Recent Literature
Organocopper reagents smoothly react with heterocyclic propargyl mesylates at
low temperature to produce N-fused heterocycles. The copper reagent generates
allenyl intermediates in situ via SN2'-substitution and copper
byproducts also mediate the subsequent cycloisomerization step.
D. Chernyak, S. B. Gadamsetty, V. Gevorgyan, Org. Lett., 2008,
10, 2307-2310.
An efficient and one-step synthesis of 3-aminoindolizines or benz[e]indolizines
from the reactions of propargyl amines or amides with heteroaryl bromides is
realized by a tandem reaction using Pd/Cu catalysts, which catalyze coupling and
cycloisomerization reactions in the same vessel.
Y. Liu, Z. Song, B. Yan, Org. Lett., 2007,
9, 409-412.
A gold(III)-catalyzed multicomponent coupling/cycloisomerization reaction of
heteroaryl aldehydes, amines, and alkynes under solvent-free conditions or in
water provides rapid access to substituted aminoindolizines with high atom
economy and high catalytic efficiency.
B. Yan, Y. Liu, Org. Lett., 2007,
9, 4323-4326.
A Fe(acac)3/TBAOH-catalyzed three-component
coupling-cycloisomerization reaction of aldehydes, terminal alkynes, and amines
provides a diverse range of heterocyclic compounds such as aminoindolizines and
quinoline derivatives in good yields.
S. S. Patil, S. V. Patil, V. D. Bobade, Synlett, 2011,
2379-2383.
A copper-catalyzed cycloisomerization of 2-pyridyl-substituted propargylic
acetates and its derivatives offers an efficient route to C-1 oxygenated
indolizines with a wide range of substituents under mild reaction conditions.
The presented method could be readily applied to the synthesis of indolizinones
through a cyclization/1,2-migration of tertiary propargylic alcohols.
B. Yan, Y. Zhou, H. Zhang, J. Chen, Y. Liu, J. Org. Chem.,
2007,
72, 7783-7786.
An efficient two-component palladium-catalyzed arylation/cyclization cascade
approach toward various highly functionalized N-fused pyrroloheterocycles in
very good yield proceeds via a palladium-catalyzed coupling of aryl halides with
propargylic esters or ethers followed by a 5-endo-dig cyclization.
D. Chernyak, C. Skontos, V. Gevorgyan, Org. Lett., 2010,
12, 3242-3245.
An Au-catalyzed synthesis of fused pyrroloheterocycles from diverse
propargyl-substituted heterocycles proceeds via alkyne-vinylidene
isomerization with concomitant 1,2-shift of hydrogen, silyl, and stannyl
groups. This method allows for mild and efficient synthesis of diverse C-2
substituted N-heterocycles.
I. V. Seregin, V. Gevorgyan, J. Am. Chem. Soc., 2006, 128, 12050-12051.
Conditions for the palladium-catalyzed direct arylation of a wide range of
heterocycles with aryl bromides employ a stoichiometric ratio of both coupling
partners, as well as a substoichiometric quantity of pivalic acid, which results
in significantly faster reactions. An evaluation of the influence of the nature
of the aryl halide has also been carried out.
B. Liégault, D. Lapointe, L. Caron, A. Vlassova, K. Fagnou, J. Org. Chem., 2009,
74, 1826-1834.
