Regio- and stereoselective insertion reactions of thiiranes into Pt-Mn (or Re) bond in organoplatinum-manganese or -rhenium heterodinuclear complexes as intermediates toward desulfurization reaction

Full text of DOI:10.1021/ja993185m

Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.
170
J. Am. Chem. Soc. 2000, 122, 170-171
(or rhenium) complexes (dppe)RPtM(CO)5 (M ) Mn: R ) Me
(1a), Et (1b), CH2CMe3 (1c); M ) Re: R ) Me (2a), Et (2b)),
giving new heterodinuclear complexes (dppe)RPtSC1R2RCH2M-
Regio- and Stereoselective Insertion Reactions of
Thiiranes into Pt-Mn (or Re) Bond in
Organoplatinum-Manganese or -Rhenium
Heterodinuclear Complexes as Intermediates toward
Desulfurization Reaction
(CO)5 (3-9) or anti- and syn-(dppe)RPtSCMeHCMeHCOMn-
(CO)4 (10) from which stereoselective desulfurization occurs to
afford olefin and Pt-S-M type complexes.
The heterodinuclear Pt-Mn(or Re) complexes 1a-c and 2a-b
were prepared in good yields by simple metathetical reactions of
PtRCl(dppe) with the corresponding transition-metal anions Na-
[M(CO)5] (M ) Mn, Re) in THF (eq 1).7
Sanshiro Komiya,* Shin-ya Muroi, Masaki Furuya, and
Masafumi Hirano
Department of Applied Chemistry
Tokyo UniVersity of Agriculture and Technology
2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan
ReceiVed September 3, 1999
Introduction of direct heterotransition-metal direct bonds in
cluster complexes is expected to create a new era of transition-
metal chemistry in relation to multimetallic catalysis, and thus
many investigations on heterotransition-metal complexes have
been reported in recent years.1 Bimetallic catalysis such as sulfur-
ized Pt-Re oil reforming catalysts2 and Co-Mo and Ni-Mo hy-
drodesulfurization (HDS) catalysts3 shows cooperative effects of
these metals, but the origin of such effect is far from understood
at the molecular level. Although extensive research has been devo-
ted to elucidate the mechanisms of the reactions of heterodinuclear
transition-metal complexes and clusters with thiiranes and ben-
zothiophenes, few examples of direct participation of both metal
centers have been found in the literature.4 Also, factors controlling
selectivity in activation of thiiranes have not been well understood
despite their importance as model reactions as well as their wide
applications to chemical transformation of sulfur-containing
compounds.5 We previously reported model complexes of het-
erodinuclear organometallic complexes of group 10 and 6 (or 9)
metals, where unique organic group transfer reactions along metals
and enhanced CO insertion reactions have been demonstrated.6
Now we have found a highly regio- and stereocontrolled ring-
opening reaction of thiiranes with organoplatinum-manganese
The molecular structure of 1a was unequivocally determined
by X-ray crystallography.8 The platinum fragment has a distorted
square planar geometry, and two of the carbonyl groups of the
Mn(CO)5 fragment are distorted away from the ideal octahedron
due to the formation of semi-bridging character. The bond length
of Pt1-Mn1 of 2.795 Å is typical of covalent single bond.
When 1a was treated with thiiranes such as ethylene sulfide,
propylene sulfide, and isobutylene sulfide, regioselective insertion
of the Pt-M bond into the less hindered C-S bond took place
to give the new dinuclear complexes (dppe)RPtSC(1R)(2R)C(3R)-
(4R)M(CO)5, (M ) Mn: R ) Me, 1R ) 2R ) 3R ) 4R ) H (3);
R ) Me, 1R ) Me or H, 2R ) H or Me, 3R ) 4R ) H (4); R )
2
3
4
1
2
1R ) R ) Me, R ) R ) H (5). M ) Re: R ) Me, R ) R
3
4
1
2
3
) R ) R ) H (6); R ) R ) Me or H, R ) H or Me, R )
4R ) H (7); R ) Et, R ) R ) R ) R ) H (8); R ) Et, R
1
2
3
4
1
2
3
4
) Me or H, R ) H or Me, R ) R ) H (9)) (Scheme 1).9
Isolation of such insertion products is still very rare to date, since
further desulfurization usually takes place to liberate olefins.
Acidification of 4 with HCl in toluene liberated iPrSH
exclusively in 72% yield. Similarly, 5 and 7 liberated tBuSH and
iPrSH, respectively. These facts indicate that the ring-opening
reactions of thiiranes take place only at the less hindered C-S
bond. On the other hand, treatment of 1a with cis- and trans-2-
butene sulfides resulted in further carbonylation and S-coordina-
tion to Mn to give thiamanganacycle-coordinated platinum
* Corresponding author. Telephone: +81 42 388 7043. Fax: +81 42 387
7500. E-mail: komiya@cc.tuat.ac.jp.
(1) (a) Chetcuti, M. J. ComprehensiVe Organometallic Chemistry II; Abel,
E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon: Oxford, 1995; Vol.
10, pp 351-385. (b) Braunstein, P.; Rose, J. ComprehensiVe Organometallic
Chemistry II; Abel, E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon:
Oxford, 1995; Vol. 10, pp 23-84. (c) Beringhelli, T.; Ceriotti, A.; D’Alfonso,
G.; Della Pergola, R.; Ciani, G.; Moret, M.; Sironi, A. Orgnaometallics 1990,
9, 1053-1059. (d) Knorr, M.; Strohmann, C. Organometallics 1999, 18, 248-
257.
(2) (a) Xiao, J.; Puddephatt, R. J. Coord. Chem. ReV. 1995, 143, 457-
500. (b) Bianchini, C.; Meli, A. J. Chem. Soc., Dalton Trans. 1996, 801-
814. (c) Hao, L.; Xiao, J.; Vittal, J. J.; Puddephatt, R. J. Organometallics
1997, 16, 2165-2174.
(3) (a) Raiz, U.; Curnow, O.; Curtis, M. D. J. Am. Chem. Soc. 1991, 113,
1416-1417. (b) Riaz, U.; Curnow, O. J.; Curtis, M. D. J. Am. Chem. Soc.
1994, 116, 4357-4363. (c) Mansour, M. A.; Curtis, M. D.; Kampf, J. W.
Organometallics 1995, 14, 5460-5462. (d) Curtis, M. D.; Druker, S. H. J.
Am. Chem. Soc. 1997, 119, 1027-1036.
(4) (a) Matsunaga, P. T.; Hillhouse, G. L. Angew. Chem., Int. Ed. Engl.
1994, 33, 1748-1749. (b) Baranger, A. M.; Hanna, T. A.; Bergman, R. G. J.
Am. Chem. Soc. 1995, 117, 10041-10046. (c) Uhl, W.; Grapner, R.; Reuter,
H. J. Organomet. Chem. 1996, 523, 227-234. (d) Proulx, G.; Bergman, R.
G. Organometallics 1996, 15, 133-141. (e) Adams, R. D.; Queisser, A.;
Yamamoto, J. H. J. Am. Chem. Soc. 1996, 118, 10674-10675. (f) Adams, R.
D.; Yamamoto, J. H. Organometallics 1997, 16, 1430-1439. (g) Etienne,
M.; Mathieu, R.; Donnadieu, B. J. Am. Chem. Soc. 1997, 119, 3218-3228.
(h) Adams, R. D.; Perrin, J. L. J. Am. Chem. Soc. 1999, 121, 3984-3991.
(5) (a) Sander, M. Chem. ReV. 1966, 66, 297-335 and references therein
(b) Mangette, J. E.; Powell, D. R.; West, R. Organometallics 1995, 14, 3551-
3557.
(6) (a) Komiya, S.; Endo, I. Chem. Lett. 1988, 1709-1712. (b) Fukuoka,
A.; Sadashima, T.; Endo, I.; Ohashi, N.; Kambara, Y.; Sugiura, T.; Miki, K.;
Kasai, N.; Komiya, S. Organometallics 1994, 13, 4033-4044. (c) Fukuoka,
A.; Sadashima, T.; Sugiura, T.; Wu, X.; Mizuho, Y.; Komiya, S. J. Organomet.
Chem. 1994, 473, 139-147. (d) Fukuoka, A.; Sugiura, T.; Yasuda, T.; Taguchi,
T.; Hirano, M.; Komiya, S. Chem. Lett. 1997, 329-330. (e) Fukuoka, A.;
Fukagawa, S.; Hirano, M.; Komiya, S. Chem. Lett. 1997, 377-378. (f) Yasuda,
T.; Fukuoka, A.; Hirano, M.; Komiya, S. Chem. Lett. 1998, 29-30.
complexes, anti- and syn-(dppe)MePtSCHMeCHMeCOMn(CO)5
(10), respectively, whose structures were unequivocally deter-
mined by X-ray structure analysis (Figure 1).10
(7) Physical and spectroscopic data for 1a are as follows: Yield 87%, 1H
NMR (CD2Cl2, 300 MHz) δ 0.81 (dd, 3H, JH-P ) 6.6, 6.3 Hz, JH-Pt ) 61.0
Hz, PtMe), 2.1-2.5 (m, 4H, PCH2CH2P), 7.5-7.9 (m, 20H, Ph); 31P{1H}
NMR (acetone-d6, 122 MHz) δ 49.1(s, 1P, JPt-P ) 1856 Hz, dppe), 59.2 (s,
1P, JPt-P ) 3394 Hz, dppe); IR (KBr, cm-1) 2036, 1945, 1933, 1920, 1907.
Λ (S cm2 mol-1, in THF) ) 0.0346. Anal. Found: C, 40.22; H, 2.90%. Calcd
for C32H27O5P2PtMn: C, 41.12; H, 2.91%. Molar electric conductivities of
these complexes in THF are very small, indicating that the Pt-M bond has
little ionic but covalent character. However, the observed ν(CO) bands are
close to those of [M(CO)5]-1, suggesting that the actual oxidation states of Pt
and M are close to +2 and -1 rather than their formal oxidation states of +1
and 0, respectively.
(8) X-ray data for 1a.: triclinic, P1h (No.2), R(Rw) ) 0.044 (0.077).
1
(9) Physical and spectroscopic data for 3 are as follows: Yield 81%, H
NMR (acetone-d6, 300 MHz) δ 0.58 (dd, 3H, JH-P ) 6.6, 4.8 Hz, JH-Pt
)
58.0 Hz, PtMe), 1.90 (t, 2H, J ) 6.9 Hz, SCH2CH2), 2.4-2.7 (m, 4H,
PCH2CH2P), 2.57 (m, 2H, SCH2CH2), 7.4-8.0 (m, 20H, Ph); 31P{1H} NMR
(acetone-d6, 122 MHz) δ 45.9 (s, 1P, JPt-P ) 1820 Hz, dppe), 47.4 (s, 1P,
JPt-P ) 3289 Hz, dppe); IR (KBr, cm-1) 2051, 1927, 1949, 1927, 1858. Λ (S
cm2 mol-1 in THF) ) 0.170. Anal. Found: C, 47.46; H, 4.07; S, 3.78%.
Calcd for C34H31O5SP2PtMn: C, 47.28; H, 3.62; S, 3.71%.
(10) X-ray data for anti- and syn-10. anti-10‚Me2CO from acetone: triclinic,
P1h(No. 2) R(Rw) ) 0.060 (0.080). syn-10‚0.5C6H6 from benzene/hexane:
triclinic, P1h(No. 2), R (Rw) ) 0.079 (0.107).
10.1021/ja993185m CCC: $19.00 © 2000 American Chemical Society
Published on Web 12/22/1999

Evaluation Only. Created with Aspose.PDF. Copyright 2002-2021 Aspose Pty Ltd.
Communications to the Editor
J. Am. Chem. Soc., Vol. 122, No. 1, 2000 171
Scheme 1
[Mn(CO)5]-, whereas 1c remained unreacted under these reaction
conditions. Therefore heterolytic cleavage of Pt-Mn bond in
heterodinuclear complexes is most likely to take place in
complexes 1a and 1b by addition of thiirane to give the [PtR-
(dppe)]+ cation, which traps the thiirane by S-coordination. Such
prerequisite coordination of thiiranes was postulated by Adams4f
and Bergman12 for these ring-opening reactions. External SN2
attack of the [Mn(CO)5]- anion at the less hindered carbon atom
of coordinated thiirane results in the ring-opening reaction with
inversion of configuration at the carbon atom in the formation of
the complexes 10. In the case of the reaction of 2-butene sulfides,
a facile insertion of CO into the newly formed Mn(or Re)-C
bond takes place to give a coordinatively unsaturated acylman-
ganese (or -rhenium) species, to which the Pt-sulfide moiety
coordinates to Mn (or Re) to give final products. On the other
hand, the reaction of neopentyl derivative 1c with thiiranes did
not cause heterolytic dissociation of the Pt-Mn (or Re) bond.
As a result, thiiranes such as cis- and trans-2-butene sulfides are
considered to interact directly with Pt-Mn (or Re) bond to liberate
olefins with retention of configuration (Scheme 1).12 A three-
center concerted transition state has been proposed for the
desulfurization reaction of ethylene sulfide with Ni-Zr heterodi-
nuclear complexes leading to µ-S complex.13
Figure 1. The molecular structure for anti-10. The hydrogen atoms except
those in the thiamanganacycle are omitted for clarity. Ellipsoids represent
50% probability. Selected bond distances (Å) and angles (deg) for anti-
10: Pt(1)-S(1) 2.363(3), Pt(1)-C(1) 2.11(2), Mn(1)-S(1) 2.389(4), Mn-
(1)-C(32) 2.08(1), S(1)-C(29) 1.81(1), C(29)-C(30) 1.54(2), C(30)-
C(32) 1.54(2), S(1)-Pt(1)-C(1) 87.2(4), S(1)-Mn(1)-C(32) 83.3(5),
Pt(1)-S(1)-Mn(1) 111.5(2).
The rhenium analogue 2a with cis-2-butene sulfide also gave
isomorphous complex (anti-11). As revealed by the ORTEP draw-
ings, cis- and trans-2-butene sulfide gave anti and syn isomers,
respectively, indicating that the stereochemistry at the carbon in
the C-S bond cleavage of thiirane was complete inversion.
Thermolyses of these complexes were carried out to investigate
the desulfurization process. Heating of these complexes gave the
corresponding olefins and a sulfur-bridged Pt-S-M complex
(dppe)MePt(µ-S)Mn(CO)5 (12a) with retention of configuration.
Namely, heating of 4, anti- and syn-10 at 80 °C in toluene
exclusively liberated propylene, trans- and cis-2-butenes in 91,
80, and 88% yields, respectively.11 The Pt-Re derivatives gave
analogous results.
Acknowledgment. This work was financially supported by the
Ministry of Education, Science, Sports and Culture, Japan.
Supporting Information Available: Physical and spectroscopic data
for 1-12. Tables of crystallographic data, structure solution and refine-
ment, atomic coordinates, bond lengths and angles, and anisotropic thermal
parameters for 1a, anti-10 and syn-10 (PDF). X-ray crystallographic file
in CIF format. These materials are available free of charge via the Internet
at http://pubs.acs.org.
JA993185M
In contrast to the above results, reactions of neopentyl-Pt-
Mn complex 1c with cis- and trans-2-butene sulfides yielded
analogous Pt-S-Mn complex 12b and cis- and trans-2-butenes
in 98 and 96% yields at 50 °C, respectively, without formation
of intermediate. The most striking fact is that cis- and trans-2-
butene sulfides released the cis- and trans-2-butenes, respectively,
indicating that the total stereochemistry of the carbon in thiiranes
in the reaction is retention of configuration.
To elucidate the reaction mechanism, the reactions of 1a and
1c with dimethyl sulfide were performed. The methyl derivative
1a smoothly induced ionization to give a cationic methylplatinum-
(II) complex with [Mn(CO)5]- anion, [PtMe(Me2S)(dppe)]+-
(11) Physical and spectroscopic data for 12a. Yield 91%, 1H NMR (acetone-
d6, 300 MHz) δ 0.27 (dd, 3H, JH-P ) 6.6, 5.7 Hz, JH-Pt ) 60.0 Hz, PtMe),
2.2-2.6 (m, 4H, PCH2CH2P), 7.1-8.1 (m, 20H, Ph); 31P{1H} NMR (acetone-
d6, 122 MHz) δ 47.7 (s, 1P, JPt-P ) 3234 Hz, dppe), 49.6 (s, 1P, JPt-P ) 1883
Hz, dppe). Λ (S cm2 mol-1 in THF) ) 0.168. Anal. Found: C, 47.09; H,
3.72; S, 3.59%. Calcd for C32H27MnO5P2PtS‚C6H6: C, 47.04; H, 3.72; S, 2.76%.
(12) One of the reviewers commented that the concerted mechanism for
the ring-opening reaction by 1c is unlikely for steric reasons, but rather favors
dissociation mechanism. However, we prefer our mechanism via unpolarized
transition state, since the reaction of trans-2-butene sulfide with 1c showed
only slight solvent effect: the rate in benzene-d6 is slightly faster than that in
acetone-d6.
(13) (a) Baranger, A. M.; Hanna, T. A.; Bergman, R. G. J. Am. Chem.
Soc. 1995, 117, 10041-10046. (b) Holland, P. L.; Andersen, R. A.; Bergman,
R. G. Organometallics 1998, 17, 433-437.