Zinc
Name Reactions
Recent Literature
In the presence of Co(PPh3)2I2, PPh3,
water, and zinc powder, the reductive coupling of alkynes with alkenes
having an electron-withdrawing substituent proceeded smoothly in
acetonitrile to give the corresponding reductive coupling products in fair
to excellent yields. Possible mechanisms for this highly regio- and
stereoselective ene-yne reaction are proposed.
C.-C. Wang, P.-S. Lin, C.-H. Cheng, J. Am. Chem. Soc., 2002, 124, 9696-9697.
The efficient olefination from organozinc reagents with aldehydes is
exploited in a new synthesis of aryl and alkyl olefins.
J.-X. Wang, Y. Fu, Y. Hu, K. Wang, Synthesis, 2003, 1506-1510.
In acetonitrile as solvent and in the presence of a simple cobalt halide as
catalyst, the reduction by zinc dust of a mixture of aldehydes or ketones
and allylic acetates affords the corresponding homoallylic alcohols in good
yields.
P. Gomes, C. Gosmini, J. Périchon, Synthesis, 2003, 1909-1915.
A rapid and efficient procedure for the solvent-free synthesis of
homoallylic and homopropargyl alcohols has been achieved by zinc-mediated
Barbier-type reaction of carbonyl compounds at room temperature.
J.-X. Wang, X. Jia, T. Meng, L. Xin, Synthesis, 2005, 2669-2672.
J.-X. Wang, X. Jia, T. Meng, L. Xin, Synthesis, 2005, 2669-2672.
Zinc-promoted reduction of 2-(bromomethyl)alkenoates derived from
Baylis–Hillman adducts gave (E)-2-methylacrylates in good yield and
high stereoselectivity. Synthesis of the male ant pheromone (E)-2,4-dimethyl-2-hexenoic
acid was performed using this simple methodology.
L. Fernandes, A. J. Bortoluzzi, M. M. Sa, Tetrahedron, 2004, 60, 9983-9989.
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.
Cobalt complex/Zn systems effectively catalyze the reductive coupling of
activated alkenes with alkynes in the presence of water to give substituted
alkenes with very high regio- and stereoselectivity in excellent yields.
H.-T. Chang, T. T. Jayanth, C.-C. Wang, C.-H. Cheng, J. Am. Chem. Soc.,
2007,
129, 12032-12041.
A range of polysubstituted allylic zinc chlorides were obtained in good yield
using a LiCl-mediated zinc dust insertion in polysubstituted allylic chlorides.
A highly diastereoselective synthesis of homoallylic alcohols bearing up to two
adjacent quaternary centers by the addition of polysubstituted allylic zinc
reagents to carbonyl compounds.
H. Ren, G. Dunet, P. Mayer, P. Knochel, J. Am. Chem. Soc., 2007,
129, 5376-5377.
A dizinc reagent, which acts as an effective bidentate Lewis acid, is easily
prepared from diiodomethane and zinc powder.
K. Nomura, K. Oshima, S. Matsubara, Angew. Chem. Int. Ed., 2005,
44, 5860-5863.
Efficient, simple, cheap, and environmentally benign preparations of
cyclopropanes were achieved. One method is based on a 3-exo-trig cyclisation of
various electron-deficient 2-iodoethyl-substituted olefins with zinc powder in a
mixture of t-butyl alcohol and water, and the other on a 3-exo-tet
cyclisation of various 1,3-dihalopropanes with zinc powder in ethanol.
D. Sakuma, H. Togo, Tetrahedron, 2005,
61, 10138-10145.
D. Sakuma, H. Togo, Tetrahedron, 2005,
61, 10138-10145.
The CoI2(dppe)-catalyzed diastereoselective reductive [3 + 2]
cycloaddition of allenes and enones gives cyclopentanols in very good yields in
the presence of zinc, zinc iodide, and water.
H.-T. Chang, T. T. Jayanth, C.-H. Cheng, J. Am. Chem. Soc., 2007,
129, 4166-4167.
Upon treatment with aqueous sodium hydroxide in DMF, a range of chalcones
underwent Michael addition reactions with nitroalkanes. The resulting
adducts were reduced in situ with Zn/HCl (aq) to afford substituted Δ1-pyrrolines
in high yields after a cyclization.
Y. Liang, D. Dong, Y. Lu, Y. Wang, W. Pan, Y. Chai, Q. Liu, Synthesis, 2006, 3301-3304.
An efficient and convenient nickel-catalyzed cyclization of 2-iodoanilines
with alkynyl aryl ketones gives 2,4-disubstituted quinolines. Naturally
occurring quinoline derivatives have been prepared in good yields. The
mechanism is discussed.
R. P. Korivi, C.-H. Cheng, J. Org. Chem., 2006, 71, 7079-7082.
