Nickel(0) triethyl phosphite complex-catalyzed allylic substitution with retention of regio- and stereochemistry

Article abstract of DOI:10.1021/ol702122d

(Chemical Equation Presented) Nickel(0) triethyl phosphite complex-promoted reaction of allylic acetates with thiols produced allylic sulfides with retention of configuration without allylic rearrangement. A similar reaction of allylic acetates with alcohols and phenols also proceeded with retention of regio- and stereochemistry.

Full text of DOI:10.1021/ol702122d

ORGANIC
LETTERS
2007
Vol. 9, No. 22
4603-4606
Nickel(0) Triethyl Phosphite
Complex-Catalyzed Allylic Substitution
with Retention of Regio- and
Stereochemistry
Yasutaka Yatsumonji, Yusuke Ishida, Akira Tsubouchi, and Takeshi Takeda*
Department of Applied Chemistry, Graduate School of Engineering, Tokyo UniVersity
of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
takeda-t@cc.tuat.ac.jp
Received August 29, 2007
ABSTRACT
Nickel(0) triethyl phosphite complex-promoted reaction of allylic acetates with thiols produced allylic sulfides with retention of configuration
without allylic rearrangement. A similar reaction of allylic acetates with alcohols and phenols also proceeded with retention of regio- and
stereochemistry.
Transition metal-catalyzed allylic substitution is one of the
most frequently employed transformations in organic syn-
thesis, and a variety of transition metal complexes have been
explored as catalysts for the regio- and stereoselective
reactions.1 The reactions catalyzed by these complexes are
generally classified into two categories: the branch selective
reaction,1a,2 in which a nucleophile attacks at the more
hindered side of the allylic system, and the linear selective
reaction, which involves nucleophilic attack at the less
substituted allylic terminus.3 Recently, the regiospecific
reactions have also been reported.4
allylic alcohol derivatives with soft nucleophiles have been
investigated, these reactions end up with the formation of
regio- and stereoisomeric mixtures. Recently we reported the
transformation of alkenyl and aryl halides into sulfides
(2) For recent examples: [Pd]: (a) Dai, L.-X.; Tu, T.; You, S.-L.; Deng,
W.-P.; Hou, X.-L. Acc. Chem. Res. 2003, 36, 659-667. [W]: (b) Malkov,
A. V.; Baxendale, I. R.; Dvorˇa´k, D.; Mansfield, D. J.; Kocˇovsky´, P. J. Org.
Chem. 1999, 64, 2737-2750. (c) Trost, B. M.; Hung, M.-H. J. Am. Chem.
Soc. 1983, 105, 7757-7759. [Mo]: (d) Belda, O.; Moberg, C. Acc. Chem.
Res. 2004, 37, 159-167. (e) Trost, B. M.; Dogra, K.; Hachiya, I.; Emura,
T.; Hughes, D. L.; Krska, S.; Reamer, R. A.; Palucki, M.; Yasuda, N.;
Reider, P. J. Angew. Chem., Int. Ed. 2002, 41, 1929-1932. [Rh]: (f)
Kazmaier, U.; Stolz, D. Angew. Chem., Int. Ed. 2006, 45, 3072-3075. (g)
Hayashi, T.; Okada, A.; Suzuka, T.; Kawatsura, M. Org. Lett. 2003, 5,
1713-1715. [Ir]: (h) Defieber, C.; Ariger, M. A.; Moriel, P.; Carreira, E.
M. Angew. Chem., Int. Ed. 2007, 46, 3139-3143. (i) Helmchen, G.; Dahnz,
A.; Du¨bon, P.; Schelwies, M.; Weihofen, R. Chem. Commun. 2007, 675-
691. (j) Polet, D.; Alexakis, A.; Tissot-Croset, K.; Corminboeuf, C.; Ditrich,
K. Chem.-Eur. J. 2006, 12, 3596-3609. (k) Ohmura, T.; Hartwig, J. F. J.
Am. Chem. Soc. 2002, 124, 15164-15165. (l) Takeuchi, R.; Ue, N.; Tanabe,
K.; Yamashita, K.; Shiga, N. J. Am. Chem. Soc. 2001, 123, 9525-9534.
[Ru]: (m) Bruneau, C.; Renaud, J.-L.; Demerseman, B. Chem.-Eur. J.
2006, 12, 5178-5187. (n) Ferna´ndez, I.; Hermatschweiler, R.; Pregosin,
P. S.; Albinati, A.; Rizzato, S. Organometallics 2006, 25, 323-330. (o)
Trost, B. M.; Fraisse, P. L.; Ball, Z. T. Angew. Chem., Int. Ed. 2002, 41,
1059-1061.
The nickel-catalyzed regio- and stereoselective allylic
substitution with hard nucleophiles such as the Grignard
reagent have been reported.5 Nickel complexes, however,
have retained less attention in allylic substitution with soft
6
nucleophiles. Although Ni(dppb)2 and Ni[1,2-bis[N-methyl-
7
N-(diphenylphosphinoamino)ethane]]2 -catalyzed reactions of
(1) (a) Leahy, D. K.; Evans, P. A. In Modern Rhodium-Catalyzed Organic
Reactions; Evans, P. A., Ed.; Wiley-VCH: Weinheim, Germany, 2005; pp
191-214. (b) Heumann, A. In Transition Metals for Organic Synthesis;
Beller, M.; Bolm, C., Eds.; Wiley-VCH: Weinheim, Germany, 2004; Vol.
1, pp 251-264. (c) Tsuji, J. Palladium Reagents and Catalysts, New
PerspectiVes for the 21st Century; John Wiley & Sons: Chichester, UK,
2004. (d) Hegedus, L. S. In Transition Metals in the Synthesis of Complex
Organic Molecules; Hegedus, L. S., Ed.; University Science Book:
Sausalito, CA, 1999; pp 245-286.
(3) For recent examples, see: [Pd]: (a) Pa`mies, O.; Die´guez, M.; Claver,
C. J. Am. Chem. Soc. 2005, 127, 3646-3647. (b) Hilgraf, R.; Pfaltz, A.
AdV. Synth. Catal. 2005, 347, 61-77. (c) Trost, B. M. Tetrahedron 1977,
33, 2615-2649. [Ru]: (d) Kawatsura, M.; Ata, F.; Wada, S.; Hayase, S.;
Uno, H.; Itoh, T. Chem. Commun. 2007, 298-300.
10.1021/ol702122d CCC: $37.00
© 2007 American Chemical Society
Published on Web 09/29/2007

catalyzed by the less expensive and air-stable Ni[P(OEt)3]4
1.8 Here we report the nickel complex 1-catalyzed allylic
substitution with heteronucleophiles, which proceeds with
retention of regio- and stereochemistry.
Scheme 1
Allylic sulfides are useful synthetic intermediates, and the
regioselective reactions of allylic alcohols and their deriva-
tives with thiols catalyzed by palladium9 and rhodium10 have
been reported. These facts prompted us to investigate the
practical transformation of allylic acetates 2 into sulfides 3
with thiols 4 in the presence of a catalytic amount of 1
(Scheme 1).
After benzenethiol (4a, 1.2 equiv) was treated with sodium
hydride, the resulting thiolate was treated with (E)-3-phenyl-
prop-2-enyl acetate (2a) in the presence of 1 (5 mol %) in
THF/DMF (2:1) at reflux to produce (E)-1-phenyl-3-(phe-
nylthio)propene (3a) in 96% yield (Table 1, entry 1). No
formation of the (Z)-isomer 3c was observed. Likewise, the
reaction of (Z)-3-phenylprop-2-enyl acetate (2b) with 4a
resulted in the exclusive formation of the (Z)-allylic sulfide
3c without ZfE isomerization (entry 3). All the reactions
of primary allylic acetates with 4a proceeded with complete
retention of regio- and stereochemistry to produce allylic
sulfides 3 in high yields. The reactions with ethanethiol (4b)
and 2-methyl-2-propanethiol (4c) at 50 °C revealed the same
selectivity.
(4) [Pd]: (a) Fristrup, P.; Jensen, T.; Hoppe, J.; Norrby, P.-O. Chem.-
Eur. J. 2006, 12, 5352-5360. (b) Lu¨ssem, B. J.; Gais, H.-J. J. Org. Chem.
2004, 69, 4041-4052. (c) Faller, J. W.; Sarantopoulos, N. Organometallics
2004, 23, 2179-2185. (d) Gouriou, L.; Lloyd-Jones, G. C.; Vyskocˇil, Sˇ.;
Kocˇovsky´, P. J. Organomet. Chem. 2003, 687, 525-537. (e) Fairlamb, I.
J. S.; Lloyd-Jones, G. C.; Vyskocˇil, Sˇ.; Kocˇovsky´, P. Chem.-Eur. J. 2002,
8, 4443-4453. (f) Lloyd-Jones, G. C.; Stephen, S. C.; Murray, M.; Butts,
C. P.; Vyskocˇil, Sˇ.; Kocˇovsky´, P. Chem.-Eur. J. 2000, 6, 4348-4357. (g)
Kocˇovsky´, P.; Vyskocˇil, Sˇ.; C´ısaˇrova´, I.; Sejbal, J.; Tisˇlerova´, I.; Smrcˇina,
M.; Lloyd-Jones, G. C.; Stephen, S. C.; Butts, C. P.; Murray, M.; Langer,
V. J. Am. Chem. Soc. 1999, 121, 7714-7715. (h) Butts, C. P.; Crosby, J.;
Lloyd-Jones, G. C.; Stephen, S. C. Chem. Commun. 1999, 1707-1708. (i)
Vyskocˇil, Sˇ.; Smrcˇina, M.; Hanusˇ, V.; Pola´sˇek, M.; Kocˇovsky´, P. J. Org.
Chem. 1998, 63, 7738-7748. (j) Lloyd-Jones, G. C.; Stephen, S. C. Chem.-
Eur. J. 1998, 4, 2539-2549. (k) Lloyd-Jones, G. C.; Stephen, S. C. Chem.
Commun. 1998, 2321-2322. (l) Hayashi, T.; Kawatsura, M.; Uozumi, Y.
J. Am. Chem. Soc. 1998, 120, 1681-1687. (m) Hayashi, T.; Kawatsura,
M.; Uozumi, Y. Chem. Commun. 1997, 561-562. (n) Trost, B. M.; Bunt,
R. C. J. Am. Chem. Soc. 1996, 118, 235-236. (o) Fiaud, J. C.; Malleron,
J. L. Tetrahedron Lett. 1981, 22, 1399-1402. [W]: (p) Lehmann, J.; Lloyd-
Jones, G. C. Tetrahedron 1995, 51, 8863-8874. (q) Lloyd-Jones, G. C.;
Pfaltz, A. Angew. Chem., Int. Ed. 1995, 34, 462-464. [Mo]: (r) Hughes,
D. L.; Palucki, M.; Yasuda, N.; Reamer, R. A.; Reider, P. J. J. Org. Chem.
2002, 67, 2762-2768. [Rh]: (s) Ashfeld, B. L.; Miller, K. A.; Martin, S.
F. Org. Lett. 2004, 6, 1321-1324. (t) Takeuchi, R.; Kitamura, N. New J.
Chem. 1998, 22, 659-660. (u) Evans, P. A.; Nelson, J. D. J. Am. Chem.
Soc. 1998, 120, 5581-5582. (v) Minami, I.; Shimizu, I.; Tsuji, J. J.
Organomet. Chem. 1985, 296, 269-280. [Ru]: (w) Kawatsura, M.; Ata,
F.; Hayase, S.; Itoh, T. Chem. Commun. 2007, in press; doi 10.1039/
b709218k. [Fe]: (x) Plietker, B. Angew. Chem., Int. Ed. 2006, 45, 6053-
6056. (y) Plietker, B. Angew. Chem., Int. Ed. 2006, 45, 1469-1473. (z)
Xu, Y.; Zhou, B. J. Org. Chem. 1987, 52, 974-977.
When the secondary allylic acetate 2f was subjected to
substitution with 4b, the branched sulfide 3k was obtained
regioselectively by performing the reaction in the dark in
the presence of 2,6-di-tert-butyl-p-cresol (BHT) to prevent
the photoisomerization of the product (Table 1, entry 11).11
In a similar fashion, the reaction of secondary allylic acetates
with different substitution patterns resulted in the direct
displacement of the acetoxy group with thiolates. Only when
the (E)-acetate 2g was treated with 4a was a mixture of the
regioisomers produced (80%, branch:linear ) 92:8). The
formation of the linear isomer should be attributable to the
photoisomerization during workup. Indeed the branched
allylic sulfone 5 was produced with little EfZ isomerization
by the in situ oxidation of the initially formed sulfide with
MCPBA (entry 13). Some stereoisomerization was also
observed when the (Z)-secondary acetate 2h was employed
(entry 14).
(5) (a) Chung, K.-G.; Miyake, Y.; Uemura, S. J. Chem. Soc., Perkin
Trans. 1 2000, 2725-2729. (b) Didiuk, M. T.; Morken, J. P.; Hoveyda, A.
H. Tetrahedron 1998, 54, 1117-1130. (c) Nomura, N.; RajanBabu, T. V.
Tetrahedron Lett. 1997, 38, 1713-1716. (d) Didiuk, M. T.; Morken, J. P.;
Hoveyda, A. H. J. Am. Chem. Soc. 1995, 117, 7273-7274. (e) Kobayashi,
Y.; Ikeda, E. J. Chem, Soc., Chem. Commun. 1994, 1789-1791. (f) Didiuk,
M. T.; Morken J. P.; Hoveyda A. H. Tetrahedron 1994, 50, 1117-1130
and references cited therein.
The present regio- and stereospecific allylic substitution
is expected to be extended to the preparation of various allylic
compounds. Indeed the allylic ethers 6 were obtained in high
yields by the nickel(0) 1-catalyzed reactions of primary and
secondary allylic acetates 2 with alcohols and phenols 7 in
the presence of sodium hydride as a base (Table 2). In the
reaction of the secondary allylic acetates 2, only the branched
ethers 6 were obtained regioselectively in all cases tested
without special care to prevent the isomerization.
(6) (a) Bricout, H.; Carpentier, J.-F.; Mortreux, A. Tetrahedron 1998,
54, 1073-1084. (b) Bricout, H.; Carpentier, J.-F.; Mortreux, A. Tetrahedron
Lett. 1997, 38, 1053-1056.
(7) Bricout, H.; Carpentier, J.-F.; Mortreux, A. Tetrahedron Lett. 1996,
37, 6105-6108.
(8) Yatsumonji, Y.; Okada, O.; Tsubouchi, A.; Takeda, T. Tetrahedron
2006, 62, 9981-9987.
To clarify the stereochemical outcome for the nickel(0)
1-catalyzed allylic substitution, the optically active allylic
acetate (R)-2j12 was subjected to the substitution (Scheme
2). Thus, the (R)-allylic ether (R)-6n was formed by the
(9) (a) Komine, N.; Sako, A.; Hirahara, S.; Hirano, M.; Komiya, S. Chem.
Lett. 2005, 34, 246-247. (b) Tsutsumi, K.; Yabukami, T.; Fujimoto, K.;
Kawase, T.; Morimoto, T.; Kakiuchi, K. Organometallics 2003, 22, 2996-
2999. (c) Frank, M.; Gais, H.-J. Tetrahedron: Asymmetry 1998, 9, 3353-
3357. (d) Goux, C.; Lhoste, P.; Sinou, D. Tetrahedron 1994, 50, 10321-
10330. (e) Kang, S.-K.; Park, D.-C.; Jeon, J.-H.; Rho, H.-S.; Yu, C.-M.
Tetrahedron Lett. 1994, 35, 2357-2360. (f) Goux, C.; Lhoste, P.; Sinou,
D. Tetrahedron Lett. 1992, 33, 8099-8102. (g) Deardorff, D. R.; Linde,
R. G., II; Martin, A. M.; Shulman, M. J. J. Org. Chem. 1989, 54, 2759-
2762. (h) Auburn, P. R.; Whelan, J.; Bosnich, B. J. Chem, Soc., Chem.
Commun. 1986, 146-147. (i) Trost, B. M.; Scanlan, T. S. Tetrahedron
Lett. 1986, 27, 4141-4144.
(11) A stereoisomeric mixture of the linear sulfide 3f (E:Z ) 81:19) and
the branched isomer 3k (82%, 3f:3k ) 76:24) was obtained by the reaction
of the secondary allylic acetate 2f with 4b in bright light in the absence of
BHT. We found that the branched sulfide 3k was completely isomerized
into the linear isomer 3f by irradiation with fluorescent light for 12 h.
(12) The optically active allylic acetate (R)-2j was prepared from
commercially available (R)-oct-1-en-3-ol (ACROS) by acetylation with
Ac2O.
(10) Kondo, T.; Morisaki, Y.; Uenoyama, S.; Wada, K.; Mitsudo, T. J.
Am. Chem. Soc. 1999, 121, 8657-8658.
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Org. Lett., Vol. 9, No. 22, 2007

Table 1. Nickel(0)-Catalyzed Reaction of Allylic Acetates 2
with Thiols 4a
Table 2. Nickel(0)-Catalyzed Reaction of Allylic Acetates 2
with Alcohols and Phenols 7a
a The reaction was carried out in THF/DMF at 50 °C for 20 h with 1.0
equiv of allylic acetates, 1.2 equiv of alcohol or phenol, 1.2 equiv of NaH,
and 5 mol % of Ni[P(OEt)3]4, unless otherwise noted. b Isolated yield. No
formation of the corresponding regioisomer was detected by NMR analysis
of the crude reaction mixture. c Carried out in DMF at 120 °C for 2 h with
1.2 equiv of DBU as a base.
a The reaction was carried out with 1.0 equiv of allylic acetate, 1.2 equiv
of thiol, 1.2 equiv of NaH, and 5 mol % of Ni[P(OEt)3]4. b Isolated yield.
No formation of the corresponding regioisomer was detected by NMR
analysis of the crude reaction mixture. c Carried out in THF/DMF at reflux
for 20 h. d Carried out in THF/DMF at 50 °C for 20 h. e Carried out in the
presence of a trace amount of BHT. f Isolated after oxidation with MCPBA
(10 equiv) at room temperature for 1 h.
regiochemistry, complete retention of configuration of the
asymmetric center, and excellent retention of configuration
of the double bond.
reaction with 4-methoxybenzyl alcohol (7h) as a single
regioisomer with perfect retention of configuration.13 Our
results demonstrate that Ni[P(OEt)3]4 is an excellent catalyst
that promotes allylic substitution with perfect retention of
Evans and Nelson have demonstrated that a rhodium
complex-catalyzed alkylation of an enantiomerically enriched
(E)-secondary allylic carbonate proceeded in a regio-, stereo-,
and enantiospecific manner through the formation of an enyl
Org. Lett., Vol. 9, No. 22, 2007
4605

carbonates with sodium malonate catalyzed by [Rh(CO)2Cl]2
proceeds through the preferential attack at the carbon atom
bearing the leaving group irrespective of the structure of the
starting carbonates.4s Although almost complete regioselec-
tivity was observed in the alkylation of (Z)-primary allylic
carbonates, the reaction of the secondary (Z)-isomers has
not been investigated. The nickel catalyst 1 is suitable for
the reaction of allylic acetates having a variety of substitution
patterns and gives the product with total retention of regio-
and stereochemistry even in the case of (Z)-secondary allylic
acetates.14
In conclusion, we have developed a practical method for
the highly regio- and stereospecific transformation of allylic
acetates into sulfides and ethers using the inexpensive and
air-stable nickel catalyst. Further study on the nickel(0)-
promoted substitutions of allylic compounds with various
nucleophiles is now in progress.
Scheme 2
complex.4u The present nickel-catalyzed reaction might,
therefore, proceed via the similar enyl intermediate.
Recently, the highly regio- and stereospecific allylic
substitution catalyzed by transition metal complexes has been
reported. Iron(II) complex-catalyzed allylic amination4x and
alkylation4y of (E)-primary and secondary allylic carbonates
proceed with high regioselectivity (up to 98%), leading to
the completely selective formation of (E)-allylic compounds.
Partial racemization was, however, observed in the reactions
of optically active (E)-secondary allylic carbonates. Until
now the reaction with the corresponding (Z)-isomers has not
appeared. It has also been known that the alkylation of allylic
Supporting Information Available: Experimental pro-
cedures and characterization data of all products. This
material is available free of charge via the Internet at
http://pubs.acs.org.
OL702122D
(13) The absolute configuration of 6n was assigned by comparison of
the optical rotation of the allylic alcohol obtained by the debenzylation of
6n (2,3-dichloro-5,6-dicyano-p-benzoquinone) with that of the starting allylic
alcohol. The enantiomeric excess was determined by GC analysis with a
Chiraldex B-DM column for 2j and HPLC analysis with a CHIRALCEL
OD-H column for 6n.
(14) Palladium(0)-catalyzed regio- and stereospecific allylic substitution
with retention of configuration of the allylic chiral center of the (Z)-4-
phenylbut-3-en-2-yl carbonate has been reported. However, the complete
ZfE isomerization took place when the (Z)-pent-3-en-2-yl carbonate was
used; Kazmaier, U.; Zumpe, F. L. Angew. Chem., Int. Ed. 2000, 39, 802-
804.
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Org. Lett., Vol. 9, No. 22, 2007