A new cascade for the one-pot synthesis of linear homoallylic alcohols with an allylic diindium reagent

Article abstract of DOI:10.1039/b010176l

A new cascade based on a novel allylic diindium reagent has been developed; the indium reagent prepared from 3-bromo-1-iodopropene successively coupled with carbonyl compounds and then with aryl, alkenyl or allyl halides in the presence of a Pd(0) catalys

Full text of DOI:10.1039/b010176l

A new cascade for the one-pot synthesis of linear homoallylic alcohols with an
allylic diindium reagent
Tsunehisa Hirashita, Hatsuo Yamamura, Masao Kawai and Shuki Araki*
Department of Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
E-mail: araki@ach.nitech.ac.jp
Received (in Cambridge, UK) 19th December 2000, Accepted 17th January 2001
First published as an Advance Article on the web 8th February 2001
A new cascade based on a novel allylic diindium reagent has
been developed; the indium reagent prepared from 3-bromo-
based on 1 (M = In) involving allylation of carbonyls followed
by Pd(0)-catalyzed coupling of the resulting vinylindium with
aryl, alkenyl or allyl halide, which provides a convenient one-
pot synthesis of linear homoallylic alcohols.
1
-iodopropene successively coupled with carbonyl com-
pounds and then with aryl, alkenyl or allyl halides in the
presence of a Pd(0) catalyst to afford a convenient one-pot
synthesis of linear homoallylic alcohols.
3 4
Iodobenzene and a catalytic amount of Pd(PPh ) were added
to the vinylindium reagent 3 prepared by the indium-mediated
coupling of 2 with benzaldehyde at rt for 1 h. Although the
addition of the second electrophile did not occur at rt (Table 1,
Entry 1), the expected three-component coupling product 5a
was obtained in 18% yield at 110 °C with an E+Z ratio of 46+54
(Entry 2). The addition of LiCl resulted in the dramatic
improvement both in the yield and E+Z selectivity: (E)-5a was
obtained stereoselectively in 56% yield (Entry 4). The solvent
NMP gave almost coincident results (Entry 5). The addition of
Organodimetallic compounds, which possess two metal–carbon
bonds in one molecule, are synthetically attractive reagents;
because, when they couple successively with two electrophiles,
a three-component coupling can be achieved in one pot.1
Although a number of organodimetallic reagents have hitherto
been prepared and utilized, allylic dimetal compounds of type 1
2
3
4
are rare and only a few examples such as M = Li , Zn and Sn
are known. Recently we described the preparation of the
NaOEt or the use of Pd
of Pd(PPh also resulted in the selective formation of (E)-5a
(Entries 6 and 7). The yield increased with increasing amounts
2 3
(dba) –tris(2-furyl)phosphine in place
diindium reagent 1 (M = In) by oxidative addition of indium to
3 4
)
5
3
-bromo-1-iodopropene (2). This reagent couples readily with
carbonyl compounds leading to the corresponding homoallylic
alcohols 4 via the vinylic indium compound 3 (Scheme 1).
However, the reagent 3 could not be utilized for further
transformations owing to the poor nucleophilicity of the vinylic
indium–carbon bond. Now we have established a new cascade
of Pd(PPh
8).
3 4
) , though the E/Z selectivity was diminished (Entry
The scope of this cascade was examined by changing the
carbonyl compounds and the second electrophiles (Table 2).
a
Table 2 Scope of the cascade reaction with 1 (M = In)
Scheme 1
Table 1a Tandem couplings of 1 (M = In) with benzaldehyde and
iodobenzene
DOI: 10.1039/b010176l
Chem. Commun., 2001, 387–388
This journal is © The Royal Society of Chemistry 2001
387

success of the present cascade not only provides a new synthetic
route for linear homoallylic alcohols, but also expands the scope
of organoindium chemistry in organic synthesis by means of a
combination with palladium catalysts.8
This work was supported by a Grant-in-Aid for Scientific
Research (No. 12640515) from the Ministry of Education,
Science, Sports and Culture, Japan.
Notes and references
1
(a) I. Marek and L.-F. Normant, Chem. Rev., 1996, 96, 3241; (b) I. Marek,
Chem. Rev., 2000, 100, 2887.
2
(a) J. Vollhardt, H. J. Gais and K. L. Lukas, Angew Chem., Int. Ed. Engl.,
1
2
985, 24, 610; (b) H. J. Gais and J. Vollhardt, Tetrahedron Lett., 1988,
9, 1529.
Scheme 2
3 (a) J. F. Normant, J. C. Quirion, A. Alexakis and Y. Masuda, Tetrahedron
Lett., 1989, 30, 3955; (b) L. Labaudini e` re, J. Hana ¨ı zi and J. F. Normant,
J. Org. Chem., 1992, 57, 6903; (c) J. F. Normant, New J. Chem., 1990, 14,
4
6
61; (d) L. Labaudini e` re and J. F. Normant, Tetrahedron Lett., 1992, 33,
139.
Aliphatic and a,b-unsaturated aldehydes gave the correspond-
ing three-component coupling products (Entries 1 and 2). The
coupling with the aldehydes underwent with complete E-
selectivity, though the yields were somewhat lower. Ketones
also gave the linear homoallylic alcohols (Entries 3 and 4). As
the second electrophiles, b-bromostyrene and allyl chloride
were successfully used to give 1,3- and 1,4-dienes, respectively
4
5
6
(a) D. Madec and J.-P. F e´ r e´ zou, Tetrahedron Lett., 1997, 38, 6657; (b) D.
Madec and J.-P. F e´ r e´ zou, Tetradron Lett., 1997, 38, 6661.
T. Hirashita, T. Kamei, T. Horie, H. Yamamura, M. Kawai and S. Araki,
J. Org. Chem., 1999, 64, 172.
(a) P. Cintas, Synlett, 1995, 1087; (b) J. A. Marshall, Chemtracts-Organic
Chemistry, 1997, 10, 481; (c) C.-J. Li and T.-H. Chan, Tetrahedron,
1999, 55, 11 149; (d) B. C. Ranu, Eur. J. Org. Chem., 2000, 2347.
(Entries 5 and 6). The most plausible mechanism is depicted in
Scheme 2. The vinylindium 3 undergoes transmetallation to a
vinylpalladium(II) intermediate, which gives the three-compo-
nent coupling products 5 by reductive elimination.
7 (a) I. P e´ rez, J. P. Sestelo and L. A. Sarandeses, Org. Lett., 1999, 1, 1267.
Vinylindium compounds prepared from allylindation of alkynes were
reported to couple with iodobenzene in the presence of Pd(0) catalyst. (b)
N. Fujiwara and Y. Yamamoto, J. Org. Chem., 1999, 64, 4095.
In contrast to the highly reactive nature of allylic indium
8
Recently, palladium–indium mediated Barbier-type allylations of car-
bonyls were reported. (a) J. A. Marshall and C. M. Grany, J. Org. Chem.,
6
reagents, the preparation and synthetic applications of vinylic
7
indium compounds are strictly limited. The allylic diindium
1
999, 64, 8214; (b) U. Anwar, R. Grigg, M. Rasparini, V. Savic and V.
reagent 1 (M = In) possessing the two indium–carbon bonds of
distinct reactivity can be prepared readily and can now be
utilized for the tandem couplings with two electrophiles. The
Sridharan, Chem. Commun., 2000, 645; (c) U. Anwar, R. Grigg and V.
Sridharan, Chem. Commun., 2000, 933; (d) S. Araki, T. Kamei, T.
Hirashita, H. Yamamura and M. Kawai, Org. Lett., 2000, 2, 847.
388
Chem. Commun., 2001, 387–388
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