Categories: C-C Bond Formation > Oxygen-, Nitrogen-containing molecules > Active methylenes >
Alkenylations
| Related: |  |
 |
 |
 |
Recent Literature
α-Vinylated ketoester are atom-economically produced by an In(OTf)3-catalyzed
addition of β-ketoesters to welding-grade acetylene in the presence of molecular
sieves under solvent-free conditions in good to excellent yield.
M. Nakamura, K. Endo, E. Nakamura, Org. Lett., 2005,
7, 3279-3281.
A synergistic gold/gallium catalysis enables an intermolecular addition of
1,3-dicarbonyl compounds to unactivated 1-alkynes (Nakamura reaction) at room
temperature. The developed system is highly efficient with a very low gold
catalyst loading.
Y. Xi, D. Wang, X. Ye, N. G. Akhmedov, J. L. Petersen, X. Shi, Org. Lett., 2014,
16, 306-309.
[ReBr(CO)3(thf)]2 catalyzed the reactions of
1,3-dicarbonyl compounds with terminal acetylenes, which gave the corresponding
alkenyl derivatives in excellent yields.
Y. Kuninobu, A. Kawata, K. Takai, Org. Lett.,
2005,
7, 4823-4825.
A regio- and stereoselective addition of 1,3-diketones to unfunctionalized
internal alkynes under neutral conditions is achieved by using [Ir(cod)2]SbF6
as a catalyst.
G. Onodera, M. Kato, R. Kawano, Y. Kometani, R. Takeuchi, Org. Lett., 2009,
11, 5038-5041.
G. Onodera, M. Kato, R. Kawano, Y. Kometani, R. Takeuchi, Org. Lett., 2009,
11, 5038-5041
Indium-catalyzed addition of 1,3-dicarbonyl compounds to 1-iodo-1-alkynes
produces exclusively E-iodoalkenes. The iodine atom serves both as
an activating group and as a group that controls the regioselectivity of the
addition. The E-alkenyl iodide product can be further derivatized into
trisubstituted olefins in high overall yield with retention of the
stereochemistry.
H. Tsuji, T. Fujimoto, K. Endo, M. Nakamura, E. Nakamura, Org. Lett., 2008,
10, 1219-1221.
1,3-Dicarbonyl compounds add to unactivated alkynes in the presence of less than
1 mol-% of indium(III) trifluoromethanesulfonate in high to excellent yield to
give 2-alkenylated 1,3-dicarbonyl compounds. This mild reaction does not require
solvent and tolerates various functional groups.
K. Endo, T. Hatakeyama, M. Nakamura, E. Nakamura, J. Am. Chem. Soc., 2007,
129, 5264-5271.
The Bu3P-catalyzed addition of 1,3-diketones, β-keto esters and
malonates to alkynoates allows an improved, mild and efficient one pot access to
α-(gem-difunctional) cinnamate esters and to conjugated 1,3-diketones.
M. Hanédanian, O. Loreau, M. Sawicki, F. Taran, Tetrahedron, 2005,
61, 2287-2294.
A nickel-catalyzed reaction of 1,3-dicarbonyl compounds with
α-methyl-substituted propargylic carbonate incorporates a 1,3-dienyl unit at the
α-position of the 1,3-dicarbonyl compound.
N. Ishida, Y. Kamino, M. Murakami, Synlett, 2021,
32,
1621-1624.
An organocatalytic asymmetric cascade Michael reaction of α,β-unsaturated
aldehydes with bromomalonates, efficiently catalyzed by chiral diphenylprolinol
TMS ether in the presence of base 2,6-lutidine, gives cyclopropanes in high
enantio- and diastereoselectivities. Using NaOAc as base, a spontaneous
ring-opening of cyclopropanes leads to (E) α-substituted malonate
α,β-unsaturated aldehydes.
H. Xie, L. Zu, H. Li, J. Wang, W. Wang, J. Am. Chem. Soc.,
2007,
129, 10886-10894.
A tandem condensation of propiolamide and cyclic β-keto methyl esters in water,
followed by acid- or base-promoted intramolecular ring closure and
decarboxylation enables an efficient synthesis of a 5,6-fused 2-pyridone
ring system.
A. B. Smith, III, O. Atasoylu, D. C. Beshore, Synlett, 2009,
2643-2646.
An enantioselective Conia-ene reaction of acetylenic β-dicarbonyl compounds employs a
DTBMSegphos-Pd(II)/Yb(III) dual catalyst system that allows for the asymmetric
synthesis of all-carbon quaternary centers and generates a methylene
cyclopentane containing an
alkene that can be further manipulated.
B. K. Corkey, F. D. Toste, J. Am. Chem. Soc., 2005,
127, 17168-17169.
[ReBr(CO)3(thf)]2 catalyzed the reactions of
1,3-dicarbonyl compounds with terminal acetylenes, which gave the corresponding
alkenyl derivatives in excellent yields.
Y. Kuninobu, A. Kawata, K. Takai, Org. Lett.,
2005,
7, 4823-4825.
A Ni(II)-catalyzed Conia-ene reaction of various acetylenic
1,3-dicarbonyl compounds has been discovered. The reaction gave mono- and
bicyclic olefinic cyclopentantes in good yields in the presence of Ni(acac)2
and Yb(OTf)3.
Q. Gao, B.-F. Zheng, J.-H. Li, D. Yang, Org. Lett., 2005,
7, 2185-2188.
An organocatalytic highly enantioselective formation of vinyl-substituted
all-carbon quaternary stereocenters proceeds in good yield via nucleophilic
vinylic substitution of various α-substituted-α-cyanoacetates with
α-chloroalkenones using a dimeric cinchona alkaloid phase-transfer catalyst.
M. Bell, T. B. Poulsen, K. A. Jørgensen, J. Org. Chem., 2007,
72, 3053-3056.