Water accelerated allylation of aldehydes by using water tolerant grignard-type allylating agents from allylmagnesium chloride and various metallic salts

Article abstract of DOI:10.1246/cl.2002.376

Some water-tolerant allylating agents prepared in situ from allylmagnesium chloride and bismuth trichloride, tin tetrachloride, tin dichloride, antimony trichloride, indium trichloride, or nickel dichloride reacted with aldehydes in THF-H₂O to

Full text of DOI:10.1246/cl.2002.376

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Chemistry Letters 2002
Water Accelerated Allylation of Aldehydes by Using Water Tolerant Grignard-Type Allylating
Agents from Allylmagnesium Chloride and Various Metallic Salts
ꢀ
Tomohiro Fukuma, Sandra Lock, Norikazu Miyoshi, and Makoto Wada
Department of Chemistry, Faculty of Integrated Arts and Sciences, The University of Tokushima,
1-1 Minamijosanjima, Tokushima 770-8502
(Received October 25, 2001; CL-011052)
Some water-tolerant allylating agents prepared in situ from
produce some water-tolerant allylating agent.
allylmagnesium chloride and bismuth trichloride, tin tetrachlo-
ride, tin dichloride, antimony trichloride, indium trichloride, or
nickel dichloride reacted with aldehydes in THF–H2O to afford
the desired homoallylic alcohols in good yields. The present
reaction proceeded more smoothly than that under non-aqueous
media.
So, we investigated the reaction of the allylbismuth reagent
prepared in situ in THF from CH2 ¼ CHCH2MgCl and BiCl3
with aldehydes in non-aqueous or aqueous conditions. It was
found that the present reaction proceeded more smoothly than that
under non-aqueous media, and the yields of the corresponding
homoallylic alcohols increased under aqueous conditions rather
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than that under non-aqueous conditions as shown in Table 1. Not
only various aldehydes (both aromatic and aliphatic aldehydes;
Entries 1–3 and Entries 4–8) but also carbonyl compounds
containing a carboxyl group (Entries 10and 11) reacted smoothly
to afford the corresponding homoallylic alcohols or the allylated
lactone in good yields. It is noteworthy that nearly equimolar
amount of allylbismuth reagent was used and the reaction took
place smoothly without the protection of the carboxyl group.
The allylation reaction of carbonyl compounds is one of the
most fundamental carbon-carbon bond forming reactions in
organic synthesis, and efficient methods using allylmetallic
1
compounds have been reported in anhydrous solvents. In
general, organometallic compounds usually have to be prepared
and treated in anhydrous solvents, owing to rapid protonolysis. In
the last decade there has been increasing recognition that organic
reactions carried out in aqueous media or protic solvents may
Table 1. Allylation of carbonyl compounds by using allylbismuth reagent
a
in aqueous media
2
offer advantages over those occurring in organic solvents. For
example, protection and deprotection processes of the functional
groups such as hydroxyl groups and carboxyl groups can
sometimes be simplified.
The Grignard reagent is one of the most useful and
convenient reagents for performing allylation reactions. How-
ever, there are few reports on the allylation using allylmagne-
sium-type reagents in aqueous media.3 On the other hand,
although a lot of Barbier-type allylations in aqueous media have
been reported by using various metals such as zinc (Zn), indium
2
(
In), and tin (Sn), a Grignard-type allylation in aqueous media by
using allylating agents generated in situ from allylmagnesium
reagents and metallic salt (SnCl4 or InCl3), to our knowledge, was
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only reported by Whitesides and co-workers. However, they
have not reported the character and reactivity of their agents under
aqueous or non-aqueous conditions. Therefore, it is desirable to
develop a new stable allylating agent in aqueous media or protic
solvents and to devise an efficient method using those solvents.
Herein, we wish to report water accelerated allylation of
aldehydes by using water-tolerant Grignard-type allylating
agents from allylmagnesium chloride (CH2 ¼ CHCH2MgCl)
and various metallic salts (eq 1).
We have already reported allylation reactions of aldehydes
by the use of Bi or bismuth trichloride (BiCl3Þ—Zn, —metallic
5
iron (Fe), or —metallic aluminium (Al). We have also reported a
Furthermore, we next investigated the stereoselectivity of the
reaction of benzaldehyde with crotylating agent prepared from 1-
methyl-2-propenylmagnesium chloride (commercially available
novel aqueous Barbier-type allylation of aldehydes by using allyl
bromide in the presence of Mg and BiCl3.6 Therefore, we
speculated CH2 ¼ CHCH2MgCl might react with BiCl3 to
from Sigma-Aldrich Inc.) and BiCl , and the results are
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Copyright Ó 2002 The Chemical Society of Japan

Chemistry Letters 2002
377
Table 4. Investigation of the stability of the allylating agents in aqueous
environment
summarized in Table 2. Thus, the reaction in the presence of
BiCl3 gave predominant syn selectivity (85 : 15) although a
mixture of syn and anti isomers (59 : 49) was obtained when
Grignard reagent alone was used. It is particularly interesting that
the addition of water is also effective in the present reaction, viz.,
both chemical yield and stereoselectivity increased (Entry 3). Our
finding is comparable with syn-selective addition of crotyltrial-
kyltins (cis and trans mixture) to aldehydes. However, it is
noteworthy that bismuth compounds are less toxic than tin
compounds.
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Table 2. Stereoselectivity of crotylation of benzaldehyde
reaction of the above allylating agent9 with benzaldehyde
occurred very rapidly (within 15 min) in water to give the
homoallylic alcohol in 86% yield.
Finally, we found that the allylating agents prepared in situ
from CH2 ¼ CHCH2MgCl and various metallic salts were water-
tolerant and the reactions with these agents were accelerated by
water.
References and Notes
1
Y. Yamamoto and N. Asao, Chem. Rev., 93, 2207 (1993), and references
cited therein.
Reviews on organic reactions in aqueous media: a) C.-J. Li, Chem. Rev., 93,
These above results prompted us to try the allylation in
aqueous environment using the allylating agents generated from
Grignard reagent and various metallic salts except BiCl3. Some of
the results are summarized in Table 3, and the reactions using
NiCl2, InCl3, SnCl4, SnCl2, and SbCl3 proceeded more smoothly
in aqueous media to afford the corresponding homollylic alcohols
in good yields although AlCl3, ScCl3, and ZnCl2 were not
effective.
2
2
023 (1993). b) A. Lubineau, J. Auge, and Y. Queneau, Synthesis, 1994, 741.
c) T. H. Chan, C.-J. Li, M. C. Lee, and Z. Y. Wei, Can. J. Chem., 72, 1181
1994). d) C.-J. Li, Tetrahedron, 52, 5643 (1996). e) ‘‘Organic Synthesis in
(
Water,’’ ed. by P. A. Grieco, Blackie, London (1998), and references cited
therein.
Unexpected Barbier-Grignard allylation of aldehydes with magnesium in
THF—water has been reported. However, only aromatic aldehydes are
usable as a substrate. a) C.-J. Li and W.-C. Zhang, J. Am. Chem. Soc., 120,
3
4
9
102 (1998). b) W.-C. Zhang and C.-J. Li, J. Org. Chem., 64, 3230(1999).
a) E. Kim, D. M. Gordon, W. Schmid, and G. M. Whitesides, J. Org. Chem.,
8, 5500 (1993). b) Recently there has been a report of allylation of
Table 3. Allylation of benzaldehyde by using allyl Grignard reagent and
a
metallic salts
5
aldehydes by using commercially available tetraallyltin in water. A.
McCluskey, Green Chemistry, 1999, 167. We have also found that
benzaldehyde—tetraallyltin reaction (the molar ratio ¼ 1 : 1) in water at
room temperature for 28 h gave the corresponding homoallylic alcohol in
4c
6
6% yield, giving the quantitative yield in the presence of glucose. c) M.
Wada, unpublished results. d) Carbonyl addition of allyl unit in water with a
pre-prepared allyldibutyltin chloride has been reported. A. Boaretto, D.
Marton, G. Tagliavini, and A. Gambaro, J. Organomet. Chem., 286, 9
(1985).
5
a) M. Wada, H. Ohki, and K. Akiba, Bull. Chem. Soc. Jpn., 63, 1738 (1990).
b) M. Wada, M. Honna, Y. Kuramoto, and N. Miyoshi, Bull. Chem. Soc. Jpn.,
7
M. Wada, T. Fukuma, M. Morioka, T. Takahashi, and N. Miyoshi,
0, 2265 (1997).
6
7
Tetrahedron Lett., 38, 8045 (1997).
typical procedure of the reaction of 3-phenylpropanal with
A
CH2 ¼ CHCH2MgCl and BiCl3 is described as follows: Under an argon
ꢁ3
atmosphere, ca. 2.0M ( 1 M ¼ 1 mol dm ) THF solution of CH2 ¼
Based on the above results, we assumed that the allylating
agents prepared in situ were stable in aqueous media. Therefore,
we next investigated the stability of the allylating agent prepared
in situ. After leaving the allylating agents prepared in situ from
CH2 ¼ CHCH2MgCl and various metallic salts in THF for
several hours by the addition of H2O (THF : H2O ¼ 4 : 1), 3-
phenylpropanal was added to the reaction mixture. As shown in
Table 4, it is noteworthy that the reactivity of the allylating agent
prepared in situ to 3-phenylpropanal did not disappear for several
hours in aqueous media in the case of SnCl4, SnCl2, and BiCl3. To
our surprise, it was found that the allyating agent prepared in situ
from CH2 ¼ CHCH2MgCl and SnCl4 in THF had an enough
reactivity in aqueous media even after 3 days. Furthermore, the
CHCH2MgCl (0.6 ml, ca. 1.2 mmol) was added to THF (8 ml) solution of
ꢂ
BiCl3 (354 mg, 1.12 mmol) at 0 C. After stirring for 15 min, H2O (2 ml) was
ꢂ
added to the reaction mixture. After stirring for 5 min at 0 C and 5 min at
room temperature, 3-phenylpropanal (104 mg, 0.77 mmol) was added. After
stirring for 12 h, the reaction mixture was quenched with an aqueous 1 M
hydrochloric acid (10ml). The organic materials were extracted with diethyl
ether (30 ml ꢃ 3), and the combined organic layer was washed successively
with water and brine, and dried over Na2SO4. After evaporation of the
solvents, the residue was purified by thin layer chromatography on silica gel
(hexane : ether ¼ 4 : 1) to give the corresponding homoallylic alcohol, 1-
phenyl-5-hexen-3-ol (128 mg, 93% yield).
Y. Yamamoto, H. Yatagai, Y. Ishihara, N. Maeda, and K. Maruyama,
Terahedron, 40, 2239 (1984).
In this case, we used the allylating agent (yellow powder) obtained from
evaporation of the solvent (THF).
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