Categories: CC Bond Formation >
Synthesis of enynes
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Recent Literature
Reaction of readily accessible benzylic and allylic alkyl bromides with iodoform
followed by a one-pot double elimination procedure enables a
triphenylphosphine-free synthesis of 1-iodoalkynes including facile purification
compared with Corey-Fuchs iodoalkynylation conditions. Replacing CHI3
with CHI2Cl allows the isolation of gem-(Z)-chloro-(E)-iodoalkenes.
The use of benzhydryl bromides as nucleophiles leads to trisubstituted alkenes.
G. Pelletier, S. Lie, J. J. Mousseau, A. B. Charette, Org. Lett., 2012,
14, 5464-5467.
A simple procedure for the synthesis of substituted (E)-2-alkene-4-ynecarboxylic
esters has been achieved using hydroxyapatite-supported palladium as efficient
catalyst surface. The highly efficient catalyst can be recycled.
B. C. Ranu, L. Adak, K. Chattopadhyay, J. Org. Chem., 2008,
73, 5609-5612.
An efficient, palladium-catalyzed synthesis of 2-alkene-4-ynoates and -nitriles
by a simple reaction of vic-diiodo-(E)-alkenes with acrylic esters
and nitriles in water leads to (E)-isomers from acrylic esters
exclusively, whereas (Z)-isomers are obtained in high stereoselectivity from
reactions of acrylonitrile. The in situ prepared Pd(0) nanoparticles can be
recycled.
B. C. Ranu, K. Chattopadhyay, Org. Lett., 2007,
9, 2409-2412.
B. C. Ranu, K. Chattopadhyay, Org. Lett., 2007,
9, 2409-2412.
Deprotonation of 3,3,3-trichloropropyl-1-triphenylphosphonium chloride
generates the corresponding phosphorane, which reacts with aldehydes to give
trichloromethylated (Z)-olefins, which are useful for the synthesis
of (Z)-1,3-enynes, (Z,Z)-1-chloro-1,3-dienes, and 1,3-diynes
in high yields and stereospecificities.
M. S. Karatholuvhu, P. L. Fuchs, J. Am. Chem. Soc.,
2004, 126, 14314-14315.
Highly regio- and stereoselective reactions of readily available
2-(methoxycarbonyl)-2,3-allenols with oxalyl chloride in the presence of Et3N
or DMSO afforded methyl 2-(ethynyl)alk-2(E)-enoates and
2-(1′-chlorovinyl)alk-2(Z)-enoates, respectively, in good yields.
Y. Deng, X. Kin, C. Fu, S. Ma, Org. Lett., 2009,
11, 2169-2172.
(E)-α-Ethynyl-α,β-unsaturated esters were prepared in good yields from
allenyl acetates by treatment with 10 mol % DABCO in DMF at room temperature.
Y. Choe, P. H. Lee, Org. Lett., 2009,
11, 1445-1448.