Categories: C-O Bond Formation > Synthesis of alcohols (hydroxylation) >
Synthesis of allyl alcohols
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Recent Literature
A catalytic regio- and stereoselective 1,4-hydroboration with pinacolborane in
the presence of Ni(cod)2 and PCy3 exhibits broad substrate
scope operating on a range of substituted 1,3-dienes and occurs with generally
high levels of selectivity and efficiency. The intermediate allylboronate can be
oxidized to stereodefined allylic alcohols or can be used in stereoselective
carbonyl addition reactions.
R. J. Ely, J. P. Morken, J. Am. Chem. Soc., 2010,
132, 2534-2535.
Use of 4,5-diazafluorenone as an ancillary ligand for Pd(OAc)2
enables terminal alkenes to be converted to linear allylic acetoxylation
products in good yields and selectivity under O2. Mechanistic studies
have revealed that the ligand facilitates C-O reductive elimination from a
π-allyl-PdII intermediate, thereby eliminating the requirement for benzoquinone
as stoichiometric oxidant in this key catalytic step.
A. N. Campbell, P. B. White, I. A. Guzei, S. S. Stahl, J. Am. Chem. Soc., 2010,
132, 15116-15119.
Sodium perborate (SPB), a principal component of washing powders, can be used as
an inexpensive and eco-friendly oxidant in the palladium-catalyzed C-H
acyloxylation of alkenes in excellent regio- and stereochemistry. The reactions
used anhydrides as acyloxy sources. The method enables the conversion of both
terminal and internal alkenes, and allows even benzylic C-H oxidation.
L. T. Pilarski, P. G. Janson , K. J. Szabó, J. Org. Chem., 2011,
76, 1503-1506.
The combination of a vanadium-oxo compound with a lipase enables the regio- and
enantioconvergent transformation of racemic allyl alcohols into optically active
allyl esters. In this dynamic kinetic resolution, the vanadium compounds
catalyzes both the racemization and the transposition of the hydroxyl group,
while the lipase effects the chemo- and enantioselective esterification.
S. Akai, R. Hanada, N. Fujiwara, Y. Kita, M. Egi, Org. Lett., 2010,
12, 4900-4903.
Trichloroacetimidates of allylic alcohols, either generated in situ or in a
separate step, undergo clean enantioselective SN2′ substitution with
various carboxylic acids in the presence of a chiral palladium(II) catalyst. The
scope and limitations of this useful catalytic asymmetric allylic esterification
are defined.
J. S. Cannon, S. F. Kirsch, L. E. Overman, J. Am. Chem. Soc., 2010,
132, 15185-15191.
A regio- and diastereoselective nickel-catalyzed reductive coupling of
carbonyls with dienes in the presence of a stoichiometric amount of
bis(pinacolato)diboron furnishes allyl boronic esters as the reaction product,
which was readily converted to the derived allylic alcohol by oxidative workup.
H. Y. Cho, J. P. Morken, J. Am. Chem. Soc., 2008,
130, 16140-16141.
Pt-catalyzed enantioselective addition of
bis(pinacolato)diboron (B2(pin)2) to conjugated dienes
enables an asymmetric 1,4-dihydroxylation of 1,3-dienes. Dienes which are unable to adopt the
S-cis conformation are unreactive. For most substrates, 1,4-addition is the
predominant pathway.
H. E. Burks, L. T. Kliman, J. P. Morken, J. Am. Chem. Soc., 2009,
131, 9134-9135.
A catalytic stereoselective 1,4-diboration of conjugated dienes with B2(pin)2
and the presence of Ni(cod)2 and PCy3 as the catalyst
roceeds efficiently at low catalyst loadings and broadens the substrate scope of
current methods for catalytic diene diboration by including internal and
sterically hindered. The intermediate allylboronate was oxidized to the
stereodefined allylic 1,4-diol.
R. J. Ely, J. P. Morken, Org. Lett., 2010,
12, 4348-4351.
The presence of a base stronly improves the efficiency and the selectivity of
the Pd-catalyzed oxidation of terminal alkenes in carboxylic acids. The
methodology is particularly well adapted for the oxidation of homoallylic
alcohols, for which the resulting acyloxylated products are obtained selectively
as E-isomers in good yields.
E. Thiery, C. Aouf, J. Belloy, D. Harakat, J. Le Bras, J. Muzart, J. Org. Chem., 2010,
75, 1771-1774.
O3ReOSiPh3 promotes the 1,3-isomerization of various
allylic alcohols. Two different strategies allow the selective formation of
a single isomer. The first strategy utilizes the formation of a conjugated
alkene to ensure a high selectivity. The second strategy employs N,O-bis(trimethylsilyl)acetamide
(BSA) as an additive to remove the product from the reaction equilibrium and
works well for the isomerization of tertiary allylic alcohols.
C. Morrill, R. H. Grubbs, J. Am. Chem. Soc.,
2005,
127, 2842-2843.
C. Morrill, R. H. Grubbs, J. Am. Chem. Soc.,
2005,
127, 2842-2843.
A method for the preparation of a wide range of branched allylic esters from
terminal alkynes proceeds via a redox-neutral propargylic CH activation
employing a rhodium(I)/DPEphos catalyst.
A. Lumbroso, P. Koschker, N. R. Vautravers, B. Breit, J. Am. Chem. Soc., 2011,
133, 2386-2389.
A hydroxyl group-directed, highly regio- and stereoselective transposition of
allylic alcohols based on rhenium catalysis is suitable for a direct
isomerization of acetals into the thermodynamically preferred isomer as long as
one of the hydroxyl groups is allylic. This method will expand the scope of
rhenium-catalyzed alcohol transpositions for complex molecule synthesis.
A. T. Herrmann, T. Saito, C. E. Stivala, J. Tom, A. Zakarian, J. Am. Chem. Soc., 2010,
132, 5962-5963.
Gold N-heterocyclic carbene complexes, in conjunction with a
silver salt, were found to efficiently catalyze the rearrangement of allylic
acetates under both conventional and microwave-assisted heating. The steric hindrance of
the ligand bound to gold was found crucial as
only extremely bulky ligands permitted the isomerization.
N. Marion, R. Gealageas, S. P. Nolan, Org. Lett., 2007,
9, 2653-2656.
Efficient and stereoselective rearrangement catalyzed by only one mole-percent
gold(I) chloride/silver(I) trifluoromethanesulfonate of Baylis-Hillman acetates
afforded 2-(acetoxymethyl)alk-2-enoates under mild reaction conditions in very
good yields with 100% E-selectivity.Cyclohex-2-enone derived
Baylis-Hillman acetates gave 2-alkylidenecyclohex-3-enones by elimination of
acetic acid.
Y. Liu, D. Mao, J. Qian, S. Lou, Z. Xu, Y. Zhang, Synthesis, 2009,
1170-1174.
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