Ring opening of lactones and anhydrides induced by [Cp2ZrHCl]n

Full text of DOI:10.1021/jo951222w

796
J . Org. Chem. 1996, 61, 796-798
Ta ble 1. Syn th esis of Bis(zir con ocen yloxy)a lk yls
6-8 a n d 12 a n d th e Cor r esp on d in g Bisp h osp h in ites
9-11 a n d 13
Rin g Op en in g of La cton es a n d An h yd r id es
In d u ced by [Cp 2Zr HCl]n
Nathalie Ce´nac,† Maria Zablocka,‡ Alain Igau,†
J ean-Pierre Majoral,*,† and Aleksandra Skowronska*,‡
Laboratoire de Chimie de Coordination du CNRS,
205 route de Narbonne, 31077 Toulouse Cedex, France,
and Polish Academy of Sciences,
Centre of Molecular and Macromolecular Studies,
Sienkiewicza 112, 90-363 Lodz, Poland
Received J uly 7, 1995
For several years we have been involved in the study
of interactions between main group elements and group
4 elements, especially zirconium derivatives. Our goal
is to take advantage of the properties of group 4 elements
to develop new synthetic approaches for the synthesis of
organic or inorganic species.1
Although the Schwartz reagent [Cp2ZrHCl]n (1)2 has
been known for a long time and has been employed in a
variety of reactions, its use in reagent-promoted ring-
opening reactions is rare and is limited to a few ex-
amples.3,4 In the course of studying the reaction of 1 with
unsaturated heterocycles, we have discovered a useful
ring-opening process of oxygen, nitrogen, or phosphorus
five-membered rings.4 Herein we report on the extension
of this useful methodology which allows the mild cleavage
of various lactones and anhydrides and a one-pot syn-
thesis of di-, tri-, or tetraphosphinites.
Addition of 1 (2 equiv) to a THF solution of lactone 2,
3, or 4 at 0 °C leads quantitatively to the isolated and
fully characterized linear dizirconated compounds 6, 7,
or 8. Further addition of an electrophile such as chlo-
rodiphenylphosphine to those derivatives affords the 1,3-,
1,4-, or 1,5-diphosphinites 9, 10, or 11 (Scheme 1); the
latter transformation is simple and highly selective, and
no side products were generally detected. For example,
the same reaction performed with the R-methylene-γ-
butyrolactone 5 using 2 (or more) equiv of 1 gives rise to
the unsaturated dizirconated derivative 12, which re-
acted with chlorodiphenylphosphine to give the new
Sch em e 1. Rin g-Op en in g Rea ction of La cton es
2-5 w ith [Cp 2Zr HCl] F ollow ed by th e Exch a n ge
Rea ction w ith P h 2P Cl
† Laboratoire de Chimie de Coordination du CNRS.
‡ Polish Academy of Sciences.
(1) See for example: (a) Majoral, J .-P.; Dufour, N.; Meyer, F.;
Caminade, A.-M.; Choukroun, R.; Gervais, D. J . Chem. Soc., Chem.
Commun. 1990, 507. (b) Dufour, N.; Majoral, J .-P.; Caminade, A.-M.;
Choukroun, R.; Dromze´e, R. Organometallics 1991, 10, 45. (c) Bou-
tonnet, F.; Dufour, N.; Straw, T.; Igau, A.; Majoral, J .-P. Organome-
tallics 1991, 10, 3939. (d) Dufour, N.; Caminade, A.-M.; Basso-Bert,
M.; Igau, A.; Majoral, J .-P. Organometallics 1992, 11, 1131. (e)
Zablocka, M.; Igau, A.; Majoral, J .-P.; Pietrusiewicz, K. M. Organo-
metallics 1993, 12, 603. (f) Colombo-Khater, D.; Caminade, A.-M.;
Delavaux-Nicot, B.; Majoral, J .-P. Organometallics 1993, 58, 2861. (g)
Boutonnet, F.; Zablocka, M.; Igau, A.; Majoral, J .-P.; J aud, J .; Pi-
etrusiewicz, K. M. J . Chem. Soc., Chem. Commun. 1993, 1487. (h)
Boutonnet, F.; Zablocka, M.; Igau, A.; Majoral, J .-P.; Raynaud, B.; J aud,
J . J . Chem. Soc., Chem. Commun. 1993, 1866. (i) Igau, A.; Dufour,
N.; Mahieu, A.; Majoral, J .-P. Angew. Chem., Int. Ed. Engl. 1993, 1,
95. (j) Zablocka, M.; Boutonnet, F.; Igau, A.; Dahan, F.; Majoral, J .-
P.; Pietrusiewicz, K. M. Angew. Chem., Int. Ed. Engl. 1993, 32, 1735.
(k) Mahieu, A.; Igau, A.; J aud, J .; Majoral, J .-P. Organometallics 1995,
14, 944. (l) Boutonnet, F.; Zablocka, M.; Igau, A.; J aud, J .; Majoral,
J .-P.; Schamberger, J .; Erker, G.; Werner, S.; Kru¨ger, C. J . Chem. Soc.,
Chem. Commun. 1995, 823. (m) Zablocka, M.; Igau, A.; Ce´nac, N.;
Donnadieu, B.; Dahan, F.; Majoral, J .-P.; Pietrusiewicz, K. M. J . Am.
Chem. Soc. 1995, 117, 8083.
diphosphinite 13. No hydrozirconation of the 1,1-disub-
stituted olefinic moiety of 5 is observed.
The general applicability of the method has been
assessed using a variety of lactones. The ratio of the
number of equivalents of 1 versus the number of equiva-
lents of lactone necessary for a clean reaction is depend-
ent on the specific lactone.
The full transformation of 1,6-dioxaspiro[4.4]nonane-
2,7-dione (14) into the unexpected trizirconated linear
derivative 18, fully characterized by NMR spectroscopy,
and the well-known oxide (Cp2ZrCl)2O (17) necessitates
5 equiv of 1 (Scheme 2). Such a result can be explained
if one considers that 4 equiv of 1 are used for the ring-
opening process of the bis lactone 14, affording the
transient tetrazirconated form 15. This could be followed
by intramolecular elimination of 17, leading to the ketone
(2) Schwartz, J .; Labinger, J . A. Angew. Chem., Int. Ed. Engl. 1976,
6, 333.
(3) Wipf, P.; Smitrovich, H. J . J . Org. Chem. 1991, 56, 6494.
(4) Ce´nac, N.; Zablocka, M.; Igau, A.; Majoral, J .-P.; Pietrusiewicz,
K. M. Organometallics 1994, 12, 5166.
0022-3263/96/1961-0796$12.00/0 © 1996 American Chemical Society

Notes
J . Org. Chem., Vol. 61, No. 2, 1996 797
Sch em e 2
Sch em e 3
diphosphinite 10 and to 20. The same sequence occurs
rapidly in a one-pot synthesis involving 4 equiv of 1,
glutaric anhydride (22), and 4 equiv of chlorodiphe-
nylphosphine, giving rise to the diphosphinite 11 and 20.
The conversion of ethylenediaminetetraacetic dianhy-
dride (23) to the tetrazirconated species 24 and then into
the new hexadentate ligand 25 (Scheme 4) follows the
same reaction sequence outline in Scheme 3 but needs 8
equiv of 1 for each equivalent of the dianhydride 23 and
then 8 equiv of chlorodiphenylphosphine. Such a conver-
sion illustrates the potentiality of this ring-opening
process for the formation of polydentate ligands which
are of interest for the development of more efficient
catalytic systems.6
Extension of this methodology, using various hetero-
cycles and electrophiles, to the one-pot synthesis of a
large variety of organic and inorganic compounds is
underway.
16. Hydrozirconation of 16 with the 5th equivalent of 1
finally gives 18. Further addition of five equiv of chlo-
rodiphenylphosphine to the mixture of compounds 17 and
18 leads to the triphosphinite 19 and to the phosphine-
phosphine oxide 20. Triphosphinite 19 arises from an
exchange reaction between 18 and the chlorophosphine
while 20 comes from the reaction of the oxide 17 with
the same chlorophosphine.5
Such a zirconium-promoted ring-opening procedure can
be extended to other oxygen heterocycles such as anhy-
drides. For instance, cleavage of C-O bonds of the
succinic anhydride 21 takes place when 21 is treated with
4 equiv of 1, the two zirconium oxides 7 and 17 being
quantitatively obtained (Scheme 3). Addition of 4 equiv
of chlorodiphenylphosphine to 7 and 17 leads to the
Exp er im en ta l Section
Gen er a l. All manipulations were carried out under an argon
atmosphere, either on
a high-vacuum line using standard
Schlenk techniques or in a drybox. Solvents were freshly
distilled from dark purple solutions of sodium/benzophenone
ketyl (THF, diethyl ether), lithium aluminum hydride (pentane),
P2O5 (CH3CN), or CaH2 (CH2Cl2). C6D6 and CDCl3 were treated
respectively with LiAlH4 and CaH2, distilled, and stored under
argon. [Cp2ZrHCl]n (Schwartz reagent) (1) was synthesized by
the method of Buchwald.7
NMR chemical shifts are expressed in ppm upfield from Me4-
Si (1H and 13C) and 85% H3PO4 (31P). The 13C NMR assignments
were confirmed by proton-decoupled and/or selective hetero-
nuclear-decoupled spectra.
Typ ica l P r oced u r e for Rin g Op en in g of La cton es 2-5
a n d 14 a n d An h yd r id es 21-23. To a suspension of 1 (0.644
(5) Addition of chlorodiphenylphosphine (2 equiv) to (Cp2ZrCl)2O (1
equiv), separately prepared by a conventional method,8 leads to 20.
The first step of the reaction consists of the formation of the transient
species Cp2Zr(OPPh2)Cl (and Cp2ZrCl2) which reacts further with a
second equivalent of chlorodiphenylphosphine to give Cp2ZrCl2 and Ph2-
POPPh2. Isomerization of Ph2POPPh2 lastly affords Ph2PP(O)Ph2:
Ce´nac, N.; Zablocka, M.; Igau, A.; Majoral, J .-P.; Skowronska, A.
Unpublished results.
(6) See for example: van Rooy, A.; Orij, E. N.; Kamer, P. C. J .; van
Leeuwen, P. W. N. M. Organometallics 1995, 14, 34.
(7) Buchwald, S. L.; LaMaire, S. J .; Nielsen, R. B.; Watson, B. T.;
King, S. M. Tetrahedron Lett. 1987, 28, 3895.
(8) Reid, A. F.; Shannon, J . M.; Wailes, P. C. Aust. J . Chem. 1965,
18, 173.

798 J . Org. Chem., Vol. 61, No. 2, 1996
Notes
Sch em e 4
g, 2.5 mmol) in 5 mL of THF at 0 °C was added the lactone 2, 3,
4 or 5 (1.25 mmol) in solution in 5 mL of THF. The resulting
mixture was warmed up to room temperature and stirred for 1
h. Evaporation of the solvent gave 6, 7, 8, or 12 as a colorless
oil in a quantitative yield. Ring opening of lactone 14 is
conducted similarly with 1 (0.644 g, 2.5 mmol) and the lactone
14 (0.05 mmol), giving rise quantitatively to 17 and 18. The
same procedure is used for reactions involving anhydrides 21,
22 (4 mmol of 1, 1 mmol of 21 or 22), and 23 (8 mmol of 1, 1
mmol of 23).
(m, 1H), 7.32-7.47 and 7.73-7.93 (m, 20H); MS m/z 523 (M +
1)+. Anal. Calcd for C28H28O2P2S2: C, 64.35; H, 5.40. Found:
C, 64.29; H, 5.37.
1,4-Bu ta n ed iyl bis(d ip h en ylp h osp h in ite) (10): yield 70%;
31P{1H} NMR (C6D6) δ 112.0; 13C{1H} NMR (C6D6) δ 28.0, 69.5,
128.3, 129.1, 130.9, i-Ph not detected; 1H NMR (C6D6) δ 1.55
(m, 4H), 3.66 (m, 4H), 6.93-7.16 and 7.55-8.05 (m, 20H). The
corresponding disulfide derivative 10′ has also been identified:
31P{1H} NMR (C6D6) δ 80.1 (s, Ph2P(S)O); MS m/z 523 (M + 1)+.
Anal. Calcd for C28H28O2P2S2: C, 64.35; H, 5.40. Found: C,
64.32; H, 5.55.
1,3-B i s [(c h lo r o d i c y c lo p e n t a d i e n y lz i r c o n i o )o x y ]-
bu ta n e (6): 13C{1H} NMR (C6D6) δ 25.2, 44.4, 72.9, 77.3, 114.0,
114.2; 1H NMR (C6D6) δ 1.05 (d, 3H), 1.52 (m, 2H), 3.92-4.35
(m, 3H), 6.01, 6.02, 6.07, 6.09 (s, 20H).
1,5-P en tan ediyl bis(diph en ylph osph in ite) (11): yield 80%;
31P{1H} NMR (CDCl3) δ 111.3; 13C{1H} NMR (CDCl3) δ 22.1,
30.9, 69.8, 128.1, 129.0, 130.1, i-Ph not detected; 1H NMR
(CDCl3) δ 1.50 (m, 2H), 1.70 (tt, 4H), 3.82 (td, 4H), 7.31-7.37
and 7.44-7.53 (m, 20H). The corresponding disulfide derivative
11′ has also been identified: 31P{1H} NMR (C6D6) δ 79.9; MS
m/z 537 (M + 1)+. Anal. Calcd for C29H30O2P2S2: C, 64.91; H,
5.63. Found: C, 64.82; H, 5.75.
1,4-B i s [(c h lo r o d i c y c lo p e n t a d i e n y lz i r c o n i o )o x y ]-
1
bu ta n e (7): 13C{1H} NMR (C6D6) δ 30.9, 75.9, 113.9; H NMR
(C6D6) δ 1.52 (m, 4H), 3.93 (m, 4H), 6.05 (s, 20H).
1,5-B i s [(c h lo r o d i c y c lo p e n t a d i e n y lz i r c o n i o )o x y ]-
p en ta n e (8): 13C{1H} NMR (CDCl3) δ 22.1, 33.0, 75.6, 113.3;
1H NMR (CDCl3) δ 1.25-1.51 (m, 6H), 3.99 (t, 4H), 6.28 (s, 20H).
1,4-Bis[(ch lor od icyclop en ta d ien ylzir con io)oxy]-2-m eth -
ylen ebu ta n e (12): 13C{1H} NMR (CDCl3) δ 36.6, 74.2, 78.2,
110.0, 113.6, 113.7, 146.6; 1H NMR (CDCl3) δ 2.12 (t, 2H,
CH2Cd), 4.10 (t, 2H), 4.44 (s, 2H), 4.83 (s, 1H), 5.00 (s, 1H), 6.28
(s, 10H), 6.31 (s, 10H).
2-Met h ylen e-1,4-b u t a n ed iyl b is(d ip h en ylp h osp h in it e)
(13) (31P{1H} NMR (CDCl3) δ 112.2 and 114.0) was isolated as
its disulfide form 13′: yield 80%; 31P{1H} NMR (CDCl3) δ 81.3
and 82.3 (s, Ph2P(S)O); 13C{1H} NMR (CDCl3) δ 33.7, 62.7, 66.8,
115.75, 128.7, 128.8, 131.7, 132.1, 132.2, 134.4, 134.5, 140.6; 1H
NMR (CDCl3) δ 2.51 (t, 2H), 4.13 (td, 2H), 4.44 (d, 2H), 5.05 (d,
1H), 5.21 (d, 1H), 7.38-7.46 and 7.77-7.91 (m, 20H); MS m/z
535 (M + 1)+. Anal. Calcd for C29H28O2P2S2: C, 65.15; H, 5.28.
Found: C, 65.11; H, 5.36.
1,4,7-T r is [(c h lo r o d ic y c lo p e n t a d ie n y lzir c o n io )o x y ]-
h ep ta n e (18): 13C{1H} NMR (CDCl3) δ 29.8, 34.3, 75.7, 84.5,
114.0; 1H NMR (CDCl3) δ 1.33-2.19 (m, 8H), 3.92-4.11 (m, 5H),
6.29 (s, 30H).
1,4,7-Hep ta n etr iyl tr is(d ip h en ylp h osp h in ite) (19) (31P-
{1H} NMR (CDCl3) δ 113.0 (broad)) was isolated as its disulfide
form 19′: yield 45%; 31P{1H} NMR (CDCl3) δ 79.5 and 81.0; 13C-
{1H} NMR (CDCl3) δ 25.8, 31.1, 64.5, 76.0, 128.4, 128.5, 130.7,
131.0, 131.2, 131.4, 131.7, i-Ph not detected; 1H NMR (CDCl3) δ
1.66 (m, 8H), 3.87 (m, 4H), 4.77 (m, 1H), 7.34-7.51 and 7.75-
7.87 (m, 30H); MS m/z 797 (M + 1)+. Anal. Calcd for
N,N,N′,N′-Tetr a k is[(ch lor od icyclop en ta d ien ylzir con io)-
oxy]eth yl-1,4-eth ylen ed ia m in e (24): 13C{1H} NMR (CDCl3)
δ 52.7, 57.8, 74.3, 114.1.
Typ ica l P r oced u r e for Exch a n ge Rea ction s w ith Zir -
con a ted Sp ecies 6, 7, 8, 12, 18, a n d 24 a n d Ch lor od ip h e-
n ylp h osp h in e. To the zirconated species (1 mmol) in solution
in 10 mL of THF at -78 °C was added chlorodiphenylphosphine
(2, 4, 5, or 8 mmol), depending on the considered zirconated
compound. The resulting mixture was stirred for 12 h at room
temperature. After evaporation of the solvent diphosphinites
10 and 11 were extracted with pentane (40 mL). The diphos-
phinites 9 and 12, the triphosphinite 19, or the tetraphosphinite
25 were treated with sulfur (1.1 equiv per phosphinite function)
for 12 h at room temperature. The resulting phosphinite sulfides
were purified by chromatography eluting with a dichloromethane/
pentane (1/3) solution for 9′ and 12′ or with an acetonitrile/
dichloromethane (1/1) solution for 19′ and 26.
C
43H43O3P3S3: C, 64.81; H, 5.44. Found: C, 64.78; H, 5.37.
N,N,N′,N′-Tet r a k is[[(d ip h en ylp h osp h a n yl)oxy]et h yl]-
1,4-eth ylen ed ia m in e (25) (31P{1H} NMR (CDCl3) δ 115.3) was
isolated as its disulfide form 26: yield 50%; 31P{1H} NMR
(CDCl3) δ 82.5; 13C{1H} NMR (CDCl3) δ 53.2, 54.5, 62.7, 128.3,
131.0, 131.7, 134.1; 1H NMR (CDCl3) δ 2.55 (m, 4H), 2.79 (t,
8H), 3.93 (td, 8H), 7.35-7.41 and 7.76-7.87 (m, 40H); MS m/z
1102 (M + 1)+. Anal. Calcd for C58H60N2O4P4S4: C, 63.26; H,
5.49. Found: C, 63.18; H, 5.39.
1,3-Bu ta n ed iyl bis(d ip h en ylp h osp h in ite) (9)
(
31P{1H}
NMR (CDCl3) δ 107.0 and 112.3) was isolated as its disulfide
form 9′: yield 80%; 31P{1H} NMR (CDCl3) δ 79.2 and 81.6 (s,
Ph2P(S)O); 13C{1H} NMR (CDCl3) δ 21.9, 29.7, 60.9, 70.6, 128.3,
128.4, 130.7, 131.0, 131.2, 131.4, 131.7, i-Ph not detected; 1H
NMR (CDCl3) δ 1.21 (d, 3H), 2.06 (m, 2H), 4.07 (m, 2H), 5.04
Ack n ow led gm en t. Thanks are due to the CNRS
(France) and KBN (Poland, Grant 3T0A03709) for
financial support.
J O951222W