Categories: C-C Bond Formation > Chains >
Synthesis of 1,3-dienes
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Recent Literature
Heck Coupling with Nonactivated Alkenyl Tosylates and Phosphates: Examples
of Effective 1,2-Migrations of the Alkenyl Palladium(II) Intermediates
A. L. Hansen, J.-P. Ebran, M. Ahlquist, P.-O. Norrby, T. Skydstrup,
Angew. Chem. Int. Ed., 2006,
45, 3349-3353.
A general and mild protocol of oxygen-promoted Pd(II) catalysis allows a
selective cross-couplings of alkenyl- and arylboron compounds with various
olefins. Unlike most cross-coupling reactions, this new methodology works well
even in the absence of bases, consequently averting undesired homo-couplings.
K. S. Yoo, C. H. Yoon, J. W. Jung, J. Am. Chem. Soc., 2006,
128, 16348-16393.
The palladium-catalyzed cross-coupling reaction of air-stable potassium (E)-
and (Z)-alkenyltrifluoroborates with either (E)- or (Z)-alkenyl
bromides allows a stereoselective synthesis of conjugated dienes in moderate
to excellent yields. A variety of functional groups are tolerated in both
coupling partners.
G. A. Molander, L. A. Felix, J. Org. Chem., 2005,
70, 3950-3956.
Stereospecific coupling reactions of readily available alkenylsilanes have
been developed.
S. E. Denmark, J. Am. Chem. Soc., 1999,
121, 5821-5822.
A sequential, palladium-catalyzed, stereoselective disubstitution of
1,1-dibromoalkenes with various alkenyltrifluoroborates followed by
alkyltrifluoroborates proceeds smoothly in one pot under mild reaction
conditions to provide the corresponding trisubstituted, conjugated dienes in
excellent yield.
G. A. Molander, Y. Yokoyama, J. Org. Chem., 2006,
71, 2493-2498.
1-Alkenylboronic acid pinacol esters have been synthesized via a
palladium-catalyzed cross-coupling reaction of bis(pinacolato)diboron with
1-alkenyl halides or triflates in toluene at 50°C in the presence of KOPh in
high yields with complete retention of configuration of the double bonds. A
one-pot synthesis of unsymmetrical 1,3-dienes via the borylation-coupling
sequence has been developed.
J. Takagi, K. Takahashi, T. Ishiyama, N. Miyaura, J. Am. Chem. Soc.,
2002,
124, 8001-8006.
A variety of organolithiums are added to terminal and 2,2-disubstituted epoxides
in the presence of LTMP to generate alkenes in a completely regio- and highly
stereoselective manner. Arylated alkenes, dienes, allylsilanes, and enynes are
accessed using this procedure.
D. M. Hodgson, M. J. Fleming, S. J. Stanway, J. Org. Chem., 2007,
72, 4763-4773.
Exposure of aromatic and aliphatic N-arylsulfonyl aldimines to equal
volumes of acetylene and hydrogen gas at 45°C and ambient pressure in the
presence of chirally modified cationic rhodium catalysts provides (Z)-dienyl
allylic amines in highly optically enriched form and as single geometrical
isomers.
E. Skucas, J. R. Kong, M. J. Krische, J. Am. Chem. Soc., 2007,
129, 7242-7243.
Exposure of aldehydes or α-ketoesters to acetylene and hydrogen gas at
ambient temperature and pressure in the presence of a cationic rhodium catalysts
provides the products of a formal carbonyl Z-butadienylation. These
multicomponent couplings represent the first use of acetylene gas in
metal-catalyzed reductive C-C bond formation.
J. R. Kong, M. J. Krische, J. Am. Chem. Soc., 2006,
128, 16040-16041.
The rhodium-catalyzed reaction of aryl boronic acids with internal alkynes
and acrylates in water gives the domino coupling products. The reaction
demonstrates that water offers the possibility to discover novel
transformations.
T. Kurahashi, H. Shinokubo, A. Osuka, Angew. Chem. Int. Ed., 2006,
45, 6336-6338.
N-Vinylpyridinium and -trialkylammonium tetrafluoroborate salts represent
a new class of electrophilic coupling partner for Pd(0)-catalyzed Suzuki
cross-coupling reactions with various boronic acids in high yields. The
crystalline, air-stable, and nonhygroscopic salts are easily prepared from
activated acetylenes and pyridinium or trialkylammonium tetrafluoroborates.
K. R. Buszek, N. Brown, Org. Lett., 2007,
9, 707-710.
A stereoselective approach towards ethyl-substituted conjugated dienoic esters
utilising a Suzuki cross-coupling reaction has been achieved. In addition, a
method for their conversion into the corresponding ethyl ketones is presented.
D. Keck, T. Muller, S. Bräse, Synlett, 2006,
3457-3460.
Lewis-acid catalysts such as AlMe3, AlMe2Cl, and BPh3 significantly improve
the efficiency of the nickel-catalyzed aryl- and alkenylcyanation of alkynes.
Electron-rich cyanides, which exhibit poor reactivity in the absence of Lewis
acids, readily undergo the arylcyanation reaction under the newly disclosed
conditions.
Y. Nakao, A. Yada, S. Ebata, T. Hiyama, J. Am. Chem. Soc., 2007,
129, 2428-2429.
2-Alkynyl esters are stereo- and regioselectively converted to E-β-chloro-α-iodo-α,β-unsaturated
esters by exposure to Bu4NI in refluxing dichloroethane.
Single-isomer tetrasubstituted olefins bearing four different carbon
substituents are then synthesized by sequential palladium-catalyzed coupling
reactions.
A. B. Lemay, K. S. Vulic, W. W. Ogilvie, J. Org. Chem., 2006,
71, 3615-3618.
A novel alkenylative cyclization of enyne was developed using Cp*RuCl(cod)
under ethylene gas at room temperature.
M. Mori, N. Saito, D. Tanaka, M. Takimoto, Y. Sato, J. Am. Chem. Soc.,
2003,
125, 5606-5607.
A rhodium-catalyzed cycloisomerization converts various acyclic enynes to
their cyclic diene isomers with endoselectivity. Two different catalyst
systems have been developed, which are effective in promoting the C-C
bond-forming cyclization of enynes to furnish carbo- and heterocycles in
good to excellent yield. The mechanism is discussed.
H. Kim, C. Lee, J. Am. Chem. Soc.,
2005,
127, 10180-10181.
Various arylallenes and alkenylallenes were prepared via coupling of
allenylstannanes with aryl iodides or alkenyl iodides in the presence of Pd(PPh3)4
as catalyst, LiCl, and DMF as solvent.
C.-W. Huang, M. Shanmugasundaram, H.-M. Chang, C.-H. Cheng, Tetrahedron,
2003, 59, 3635-3641.
Highly regioselective Heck couplings of α,β-unsaturated tosylate and mesylate
derivatives with N-acyl N-vinylamines and vinyl ethers were
achieved. This method provides a cheap alternative to similar couplings using a
triflate electrophile.
A. L. Hansen, T. Skrydstrup, Org. Lett.,
2005,
7, 5585-5587.
A. L. Hansen, T. Skrydstrup, Org. Lett.,
2005,
7, 5585-5587.
