Categories: C-C Bond Formation > Oxygen-containing molecules >
Synthesis of substituted carboxylic acids, esters and amides
Recent Literature
An efficient cobalt-catalyzed reductive coupling reaction of alkyl halides
with alkenes bearing electron-withdrawing groups in the presence of water
and zinc powder in acetonitrile gave the corresponding Michael-type addition
products in high yields. The mechanism is discussed.
P. Shukla, Y.-C. Hsu, C.-H. Cheng, J. Org. Chem.,
2006,
71, 655-658.
Inexpensive and readily available Grignard reagents and stable dinuclear Cu
complexes can be used for the catalytic enantioselective conjugate addition
to simple acyclic α,β-unsaturated methyl esters providing β-substituted
chiral esters in good yields and with excellent enantioselectivities.
F. Lopez, S. R. Harutyunyan, A. Meetsma, A. J. Minnaard, B. L. Feringa,
Angew. Chem., 2005,
117, 2812-2816.
F. Lopez, S. R. Harutyunyan, A. Meetsma, A. J. Minnaard, B. L. Feringa,
Angew. Chem., 2005,
117, 2812-2816.
A highly efficient regio- and enantioselective catalytic asymmetric addition
of Grignard regeants to α,β-unsaturated esters is promoted by the CuI-Tol-BINAP
system.
S.-Y. Wang, S.-J. Ji, T.-P. Loh, J. Am. Chem. Soc., 2007,
129, 276-277.
A highly efficient regio- and enantioselective catalytic asymmetric addition
of Grignard regeants to α,β-unsaturated esters is promoted by the CuI-Tol-BINAP
system.
S.-Y. Wang, S.-J. Ji, T.-P. Loh, J. Am. Chem. Soc., 2007,
129, 276-277.
An additive-free, clean conjugate addition reaction of organosiloxanes to α,β-unsaturated
compounds is catalyzed by a cationic rhodium complex in dioxane/water. The
mechanism involves a transmetalation step between the rhodium complex and the
silicon reagent.
S. Oi, Y. Honma, Y. Inoue, Org. Lett., 2002,
4, 667-669.
A conjugate addition of organosiloxanes to α,β-unsaturated carbonyl
compounds catalyzed by a cationic rhodium complex generated from [Rh(cod)(MeCN)2]BF4
and (S)-BINAP in dioxane/water gave products in good yields and excellent
enantioselectivities.
S. Oi, A. Taira, Y. Honma, Y. Inoue, Org. Lett.,
2003, 5, 97-99.
A nickel catalyst system for 1,4-addition of trialkylboranes to
α,β-unsaturated esters has been developed. For the alkylation reaction with
9-alkyl-9-BBNs, addition of methanol was found to be
essential.
K. Hirano, H. Yorimitsu, K. Oshima, Org. Lett., 2007,
9, 1541-1544.
A (Salen)Al-Cl complex catalyzes the asymmetric conjugate addition of
hydrogen cyanide to α,β-unsaturated imides in high yields and
enantioselectivities. The cyanide adducts can readily be converted into a
variety of useful chiral building blocks, including α-substituted-β-amino
acids.
G. M. Sammis, E. N. Jacobsen, J. Am. Chem. Soc., 2003,
125, 4442-4443.
Chiral complexes of calcium promote asymmetric 1,4-addition reactions and [3+2]
cycloaddition reactions of α-amino acid derivatives with α,β-unsaturated
carbonyl compounds. The reactions proceeded smoothly in the presence of 5-10 mol
% of the chiral calcium catalyst to afford the desired adducts in high yields
with high diastereo- and enantioselectivities.
S. Saito, T. Tsubogo, S. Kobayashi, J. Am. Chem. Soc., 2007,
129, 5364-5365.
Novel chiral phosphine-olefin ligands have been designed, which acts as
bidentate in an efficient rhodium-catalyzed asymmetric 1,4-addition of aryl
boronic acids to maleimides.
R. Shintani, W.-L. Duan, T. Nagano, A. Okada, T. Hayashi, Angew. Chem.,
2005,
117, 4687-4690.
R. Shintani, W.-L. Duan, T. Nagano, A. Okada, T. Hayashi, Angew. Chem.,
2005,
117, 4687-4690.
An efficient and practical Cu-catalyzed asymmetric conjugate addition of
dialkylzinc reagents to tetrasubstituted cyclic enones afforded quaternary
all-carbon stereogenic centers in up to 95% ee. The products can be readily
functionalized to afford various synthetically versatile compounds in high
optical purity.
A. W. Hird, A. H. Hoveyda, J. Am. Chem. Soc.,
2005,
127, 14988-14989.
The efficiency of the photoinduced radical addition of tertiary amines to
olefinic double bonds is significantly enhanced and the stereoselectivity is
influenced when thiocarbonyl compounds are added to the reaction mixture.
D. Harakat, J. Pesch, S. Marinkovic, N. Hoffmann, Org. Biomol. Chem.,
2006,
4, 1202-1205.
The regioselective opening of Bn2N-α-methylserine-β-lactone with
organocuprates gave enantiopure α-methyl amino acids in excellent yields.
N. D. Smith, A. M. Wohlrab, M. Goodman, Org. Lett., 2005,
7, 255-258.
