Synthesis and structural and reactivity studies of thiatitanacyclopropane complexes [Cp?Ti(SCHCH2CH2S)]2 (Cp? = Cp, MeCp)

Article abstract of DOI:10.1021/om960108g

The complexes [Cp^?Ti(SCHCH₂CH₂S)]₂ (Cp^? = Cp (3), MeCp (4)) are readily prepared from reaction of Cp^?Ti(SCH₂CH₂CH₂S)Cl (Cp^? = Cp (1), MeCp (2)) with MeLi, AlMe₃, or t-BuLi. Both compounds are centrosymmetric dimers in the solid state containing strained thiatitanacyclopropane rings. PMe₃ cleaves these dimers, establishing equilibria between 3 and 4 and Cp^?Ti(SCHCH₂CH₂S)(PMe₃) (Cp^? = Cp (5), MeCp (6)), while compound 3 undergoes facile acidolysis with HCl, acetic acid, PhSH, and propanedithiol affording CpTiCl₃, CpTi(O₂-CMe)₃ (7), CpTi(SCH₂CH₂CH₂S)(SPh), and H⁺[CpTi(SCH₂CH₂CH₂S) ₂]^-·THF (8), respectively. The thiametallacycles react with benzophenone to give Cp^?Ti(SCH(CPh₂O)CH₂CH₂S) (Cp^? = Cp (9); MeCp (10)) while reaction with cyclohexanone gives the dimeric species [Cp^?Ti-(SCH(C₆H₁₀O)CH₂CH ₂S)]₂ (Cp^? = Cp (11); MeCp (12)). Analogous reactions with 2-methylcyclohexanone, menthone, and nopinone give related addition products with varying degrees of diastereoselectivity. The complex 3 also reacts with a series of imines to give complexes of the form CpTi(SCH(CHRNR)CH₂CH₂S), where the diastereoselectivity observed is a function of the steric demands of the substrate substituents. Reaction of 3 with nitriles, methyl isocyanate, dicyclohexylcarbodiimide, and phenyl thioisocyanate results in insertion of the substrate and subsequent enolization to give species of the form CpTi(SC=(C(R)NH)-CH₂CH₂S). The analogous reaction with phenyl isocyanate yields the bimetallic complex CpTi(SC(PhNCO)CH₂CH₂S)TiCp(SCH₂CH ₂CH₂S) (27). Crystallographic characterization of a number of these reaction products is reported. Kinetic studies of the formation of 10 and 12 are consistent with initial formation of ketone complex adducts and subsequent intra-and intermolecular C-C bond formation reactions. The nature of the products, reaction mechanisms, and reactivity of strained thiatitanacyclopropane rings are discussed in the light of EHMO calculations.

Full text of DOI:10.1021/om960108g

2320
Organometallics 1996, 15, 2320-2330
Syn th esis a n d Str u ctu r a l a n d Rea ctivity Stu d ies of
Th ia tita n a cyclop r op a n e Com p lexes
[Cp †Ti(SCHCH2CH2S)]2 (Cp † ) Cp , MeCp )
Yujin Huang, Nola Etkin, Richard R. Heyn, T. Timothy Nadasdi, and
Douglas W. Stephan*
Department of Chemistry and Biochemistry, University of Windsor,
Windsor, Ontario, Canada N9B 3P4
Received February 14, 1996X
The complexes [Cp†Ti(SCHCH2CH2S)]2 (Cp† ) Cp (3), MeCp (4)) are readily prepared from
reaction of Cp†Ti(SCH2CH2CH2S)Cl (Cp† ) Cp (1), MeCp (2)) with MeLi, AlMe3, or t-BuLi.
Both compounds are centrosymmetric dimers in the solid state containing strained thia-
titanacyclopropane rings. PMe3 cleaves these dimers, establishing equilibria between 3 and
4 and Cp†Ti(SCHCH2CH2S)(PMe3) (Cp† ) Cp (5), MeCp (6)), while compound 3 undergoes
facile acidolysis with HCl, acetic acid, PhSH, and propanedithiol affording CpTiCl3, CpTi(O2-
CMe)3 (7), CpTi(SCH2CH2CH2S)(SPh), and H+[CpTi(SCH2CH2CH2S)2]-‚THF (8), respectively.
The thiametallacycles react with benzophenone to give Cp†Ti(SCH(CPh2O)CH2CH2S) (Cp†
) Cp (9); MeCp (10)) while reaction with cyclohexanone gives the dimeric species [Cp†Ti-
(SCH(C6H10O)CH2CH2S)]2 (Cp† ) Cp (11); MeCp (12)). Analogous reactions with 2-meth-
ylcyclohexanone, menthone, and nopinone give related addition products with varying degrees
of diastereoselectivity. The complex 3 also reacts with a series of imines to give complexes
of the form CpTi(SCH(CHRNR)CH2CH2S), where the diastereoselectivity observed is a
function of the steric demands of the substrate substituents. Reaction of 3 with nitriles,
methyl isocyanate, dicyclohexylcarbodiimide, and phenyl thioisocyanate results in insertion
of the substrate and subsequent enolization to give species of the form CpTi(SC)(C(R)NH)-
CH2CH2S). The analogous reaction with phenyl isocyanate yields the bimetallic complex
CpTi(SC(PhNCO)CH2CH2S)TiCp(SCH2CH2CH2S) (27). Crystallographic characterization of
a number of these reaction products is reported. Kinetic studies of the formation of 10 and
12 are consistent with initial formation of ketone complex adducts and subsequent intra-
and intermolecular C-C bond formation reactions. The nature of the products, reaction
mechanisms, and reactivity of strained thiatitanacyclopropane rings are discussed in the
light of EHMO calculations.
In tr od u ction
been employed. Related sulfur metallacycles have
drawn less attention. Zirconocene thioaldehyde deriva-
Early transition metal mediated syntheses of organic
compounds is an area of chemistry that is developing
rapidly. Of particular interest is the potential for the
synthesis of organics containing heteroatoms. To this
end, reactive early metal reagents have been sought.1
Most recently interest has focused on the metal-
heteroatom double bonds as vehicles to organic deriva-
tives. Ti-, Zr-, and Ta-based systems containing metal-
oxo (MdO), metal-sulfido (MdS), metal-imido (MdNR),
and metal-phosphidene (MdPR) fragments have been
shown to have rich reactivity.2 While such double-
bonded moieties continue to be of interest, heteroatom
derivatives of metallacycles present an alternative class
of potential reagents. In this regard, Buchwald et al.
have applied the reactivity of Zr-imine complexes Cp2-
Zr(RNCHR′)(L) to prepare allylic amines.3 Transient
azatitanetines have been employed in the catalytic
synthesis of dihydropyrrole and tetrahydropyridine
derivatives by Livinghouse and co-workers.4 In this
case the diminished steric constraints about the metal
center of monocyclopentadienyltitanium systems have
(2) (a) Walsh, P. J .; Hollander, F. J .; Bergman, R. G. J . Am. Chem.
Soc. 1988, 110, 8729. (b) Walsh, P. J .; Hollander, F. J .; Bergman, R.
G. Organometallics 1993, 12, 3705. (c) Walsh, P. J .; Carney, M. J .;
Bergman, R. G. J . Am. Chem. Soc. 1991, 113, 6343. (d) Walsh, P. J .;
Hollander, F. J .; Bergman, R. G. J . Organomet. Chem 1992, 428, 13.
(e) Carney, M. J .; Walsh, P. J .; Hollander, F. J .; Bergman, R. G. J .
Am. Chem. Soc. 1989, 111, 8751. (f) Carney, M. J .; Walsh, P. J .;
Bergman, R. G. J . Am. Chem. Soc. 1990, 112, 6426. (g) Parkin, G.;
Bercaw, J . E. J . Am. Chem. Soc. 1989, 111, 391. (h) Whinnery, L. L.;
Hening, L. M.; Bercaw, J . E. J . Am. Chem. Soc. 1991, 113, 7575. (i)
Bennett, J . L.; Wolczanski, P. T. J . Am. Chem. Soc. 1994, 116, 2179.
(j) Schaller, C. P.; Bonanno, J . B.; Wolczanski, P. T. J . Am. Chem. Soc.
1994, 116, 4133. (k) Cummins, C. C.; Schaller, C. P.; Van Duyne, G.
D.; Wolczanski, P. T.; Chan, A. W. E.; Hoffmann, R. J . Am. Chem. Soc.
1991, 113, 2985. (l) Banaszak Hall, M. M.; Wolczanski, P. T. J . Am.
Chem. Soc. 1992, 114, 3854. (m) Winter, C. H.; Sheridan, P. H.;
Lewkebandara, T. S.; Heeg, M. J .; Proscia, J . W. J . Am. Chem. Soc.
1992, 114, 1095. (n) Hill, J . E.; Fanwick, P. E.; Rothwell, I. P. Inorg.
Chem. 1989, 28, 3602. (o) Profilet, R. D.; Zambrano, C. H.; Fanwick,
P. E.; Nash, J . J .; Rothwell, I. P. Inorg. Chem. 1990, 29, 4364. (p) Hill,
J . E.; Profilet, R. D.; Fanwick, P. E.; Rothwell, I. P. Angew. Chem.,
Int. Ed. Engl. 1990, 29, 664. (q) Roesky, H. W.; Voeler, H.; Witt, M.;
Noltmeyer, M. Angew. Chem., Int. Ed. Engl. 1990, 29, 669. (r)
McGrane, P. L.; J ensen, M.; Livinghouse, T. J . Am. Chem. Soc. 1992,
114, 5459. (s) Cundari, T. R. J . Am. Chem. Soc. 1992, 114, 7879. (t) de
With, J .; Horton, A. D. Angew. Chem., Int. Ed. Engl. 1993, 32, 903.
(u) Hou, Z.; Stephan, D. W. J . Am. Chem. Soc. 1992, 114, 10088. (v)
Ho, J .; Rousseau, R.; Stephan, D. W. Organometallics 1994, 13, 1918.
(w) Breen, T. L.; Ho, J .; Hou, Z.; Stephan, D. W. Organometallics 1993,
12, 3158. (x) Cummins, C. C.; Schrock, R. R.; Davis, W. M. Angew.
Chem., Int. Ed. Engl. 1993, 32, 756. (y) Bonanno, J . B.; Wolczanski,
P. T.; Lobkovsky, E. B. J . Am. Chem. Soc. 1994, 116, 11159. (z) Breen,
T. L.; Stephan, D. W. J . Am. Chem. Soc. 1995, 117, 11914.
X Abstract published in Advance ACS Abstracts, April 1, 1996.
(1) (a) Fagan, P. J .; Nugent, W. A. J . Am. Chem. Soc. 1988, 110,
2310. (b) Fagan, P. J .; Ward, M. D.; Caspar, J . V.; Calabrese, J . C.;
Krusic, P. J . J . Am. Chem. Soc. 1988, 110, 2981. (c) Doxsee, K. M.;
Dhen, G. S.; Knobler, C. B. J . Am. Chem. Soc. 1989, 111, 9129.
S0276-7333(96)00108-2 CCC: $12.00 © 1996 American Chemical Society

Thiatitanacyclopropane Complexes
Organometallics, Vol. 15, No. 9, 1996 2321
tives5,6 have been shown to undego alkyne insertion and
subsequent transmetalation with antimony halides to
yield stibathiolanes;7
Syn th esis of (MeCp )Ti(SCH2CH2CH2S)Cl (2). The com-
pound (MeCp)Ti(SCH2CH2CH2S)Cl was prepared in 95% yield
by a method analogous to that reported for 1. 1H NMR (C6D6,
25 °C): δ 1.18 (d, t, t, 1H, |J H-H| ) 15.3, 13.2, 2.6 Hz), 1.96 (s,
3H), 2.55 (d, t, t, “d septet”, 1H, |J H-H| ) 15.2, 2.0, 2.0 Hz),
3.71 (d, d, d, 2H, |J H-H| ) 13.5, 13.5, 1.1 Hz), 3.86 (d, d, d, 2H,
|J H-H| ) 14.0, 3.3, 3.3 Hz), 6.01 (d, d, 2H, |J H-H| ) 2.5, 2.5
Hz), 6.06 (d, d, 2H, |J H-H| ) 2.5, 2.5 Hz). 13C{1H} NMR (C6D6,
25 °C): δ 16.51, 32.83, 40.27, 114.87, 115.93, 131.72. Anal.
Calcd for C9H13ClS2Ti: C, 40.24; H, 4.88. Found: C, 40.14;
H, 4.78.
however, analogous titanium species were found them
to be much less useful from a synthetic perspective, as
attempted insertion reactions were generally not clean.8
In contrast, we have recently shown that thiatitanacy-
clopropanes derived from monocyclopentadienyltita-
nium species9 provide effective routes to amino- and
alkoxy-substituted dithiols and disulfides.10 In this
paper, we describe the first broad study of reactivity of
such thiametallacycles with a variety of unsaturated
organic reagents. The nature of the resulting titanium
complexes is established and mechanistic aspects are
considered with particular reference to issues of regio-
and stereochemistry.
Syn th esis of [Cp Ti(SCHCH2CH2S)]2 (3) a n d [(MeCp )-
Ti(SCHCH2CH2S)]2 (4). These two complexes were prepared
in similar manners, and thus only one preparation is described.
(i) A 1.4 M solution of MeLi in diethyl ether (0.33 mL, 0.47
mmol) was added dropwise to a stirred solution of CpTi(SCH2-
CH2CH2S)Cl (0.100 g, 0.39 mmol) in THF (3 mL) at -78 °C.
The mixture turned from orange to brown immediately and
became darker over a 2 h period as it was warmed to room
temperature. The solvent was removed in vacuo, and the
residue was taken up into benzene. A black-gray precipitate
was filtered from the solution, and dark brown crystals of 3
were deposited upon standing of the solution for 24 h, yield
10%. A further 65% yield was contained in the black-gray
precipitate. (ii) To a THF (20 mL) solution of CpTi(SCH2CH2-
CH2S)Cl (2.000 g, 8.0 mmol) was added AlMe3 (8.00 mL of 2.0
M in toluene). The solution was allowed to stand for 2 days.
The solution was filtered, and the solid was washed with 2 ×
5 mL portions of hexane affording black crystalline 3 in 81%
yield. For 4, the solvent was removed under vacuum, the
residue was washed with hexane and dissolved in benzene,
and the solution filtered through Celite. Addition of hexane
afforded 4. Data for 3 are as follows. 1H NMR (C4D8O, 25
°C): δ 2.15 (d, d, d, d, 1H, |J H-H| ) 14.3, 13.6, 4.4, 4.2 Hz),
3.39 (d, d, br, 1H, |J H-H| ) 14.3, 4.7 Hz), 3.50 (d, d, br, 1H,
|J H-H| ) 12.0, 4.2 Hz), 5.13, (d, br, 1H, |J H-H| ) 4.4 Hz), 5.60
(m, 1H, |J H-H| ) 13.6, 12.0, 4.7 Hz), 6.40 (s, 5H). 13C{1H} NMR
(C4D8O, 25 °C): δ 47.38, 48.93, 115.44, 115.67. Anal. Calcd
for C8H10S2Ti: C, 44.04; H, 4.62. Found: C, 44.21; H, 4.54.
Data for 4 are as follows. Yield: 82%. 1H NMR (C6D6, 25
°C): δ 1.87 (s, 3H), 2.14 (t, t, 1H, |J H-H| ) 14.1, 4.5 Hz), 3.50
(m, 2 H), 5.12 (d, t, 1H, |J H-H| ) 4.4, 1.3 Hz), 5.67 (m, 2H),
5.86 (d, d, d, 1H, |J H-H| ) 15.5, 11.5, 4.0 Hz), 6.02 (m, 1H),
6.11 (m, 1H). 13C{1H} NMR (C6D6, 25 °C): δ 16.33, 47.25,
48.44, 113.09, 114.21, 115.61, 115.73, 115.86, 128.90. Anal.
Calcd for C9H12S2Ti: C, 46.56; H, 5.21. Found: C, 46.34; H,
5.11.
Syn t h esis of Cp Ti(SCH CH 2CH 2S)(P Me3) (5) a n d
(MeCp )Ti(SCHCH2CH2S)(P Me3) (6). These two complexes
were generated in similar manners, and thus only one
preparation is described. To a suspension of 3 (85 mg, 0.195
mmol) in THF or benzene (1 mL) was added PMe3 (150 mg,
1.29 mmol). The reaction was stirred at 25 °C for 2 h and the
product characterized by NMR. Attempts to isolate the
product 5 resulted in loss of PMe3 and re-formation of 3. Data
for 5 are as follows. 1H NMR (C6D6, 25 °C): δ 0.85 (d, 9H,
|J H-H| ) 7.2 Hz), 2.70 (t, t, 1H, |J H-H| ) 11.5, 3.6 Hz), 3.00 (d,
d, br, 1H, |J H-H| ) 11.5, 4.8 Hz), 3.62 (d, br, 1H, |J H-H| ) 11.5,
3.0 Hz), 4.29 (t, d, 1H, |J H-H| ) 11.5, 3.0 Hz), 4.56 (d, d, 1H,
|J H-H| ) 3.6, 1.0 Hz), 5.95 (br s, 5H, Cp). 13C{1H} NMR (C6D6,
25 °C): δ 14.05 (d, |J P-C| ) 18.0 Hz), 37.49, 50.80, 92.24, 110.03
(d, |J P-C| ) 7.5 Hz). 31P NMR (C6D6, 25 °C): δ -5.69. Data
for 6 are as follows. 1H NMR (C6D6, 25 °C): δ 0.87 (br, 9H),
2.03 (s, 3H), 2.77 (d, d, t, 1H, |J H-H| ) 13.7, 5.3, 4.3 Hz), 3.00
(d, d, d, d, 1H, |J H-H| ) 11.0, 5.4, 1.2, 1.2 Hz), 3.57 (d, d, d, d,
1H, |J H-H| ) 13.7, 4.0, 1.4, 1.4 Hz), 4.31 (d, d, d, 1H, |J H-H| )
13.8, 11.1, 4.0 Hz), 4.51 (br,d, 1H, |J H-H| ) 3.9 Hz), 5.83 (d, d,
1H, |J H-H| ) 4.6, 2.2 Hz), 5.87 (d, d, 1H, |J H-H| ) 5.4, 2.9 Hz),
Exp er im en ta l Section
Gen er a l Da ta . All preparations were done under an
atmosphere of dry, O2-free N2 employing either Schlenk line
techniques or a Vacuum Atmospheres inert-atmosphere glove-
box equipped with a catalyst column and an atmosphere
circulation system. Solvents were reagent grade, distilled from
the appropriate drying agents under N2, and degassed by the
freeze-thaw method at least three times prior to use. 1H and
13C{1H} NMR spectra were recorded on Bruker AC-300
spectrometer operating at 300 and 75 MHz, respectively.
Trace amounts of protonated solvents were used as references,
and chemical shifts are reported relative to SiMe4. 31P and
31P{1H} NMR spectra were recorded on a Bruker AC-200
operating at 81 MHz, and chemical shifts are reported relative
to 85% H3PO4. Assignments of the 1H and 13C NMR reso-
nances and determination of coupling constant values were
based on a series of homonuclear decoupling and NOE experi-
ments. Combustion analyses were performed by Guelph Ana-
lytical Laboratories Inc., Guelph, ON, Canada, and Schwarz-
kopf Laboratories, Woodside, NY. PMe3, 1,3-propanedithiol,
benzophenone, cyclohexanone, methylcyclohexanone, (-)-men-
thone, (1R)-(+))-nopinone, methyl phenyl ketone, 2-hexanone,
benzonitrile, valeronitrile, methyl thiocyanate, dicyclohexyl-
carbodiimide, phenyl isocyanate, and phenyl isothiocyanate
were purchased from the Aldrich Chemical Co. CpTiCl3,
(MeCp)TiCl3, and the imines, PhNdCHPh, rac-(Naphth)CH-
(CH3)NdCHPh, PrNdCHPh, PhNdCH(C6H4OMe), (C6H4-
OMe)NdCHPh, and (C6H4OMe)NdCH(C6H4OMe) were pre-
pared by standard methods.11,12 Compound 1 was prepared
as previously described.9
(3) Buchwald, S. L.; Watson, B. T.; Wannamaker, W. M.; Dewan, J .
C. J . Am. Chem. Soc. 1989, 111, 4486.
(4) McGrane, P. L.; J ensen, M.; Livinghouse, T. J . Am. Chem. Soc.
1992, 114, 5459.
(5) Buchwald, S. L.; Nielsen, R. B.; Dewan, J . C. J . Am. Chem. Soc.
1987, 109, 1590.
(6) Buchwald, S. L.; Nielsen, R. B. J . Am. Chem. Soc. 1988, 110,
3171.
(7) (a) Buchwald, S. L.; Fisher, R. A.; Davis, W. M. Organometallics
1989, 8, 2082. (b) Fisher, R. A.; Nielsen, R. B.; Davis, W. M.; Buchwald,
S. L. J . Am. Chem. Soc. 1991, 113, 165.
(8) Park, J . W.; Henling, L. M.; Schaefer, W. P.; Grubbs, R. H.
Organometallics 1990, 9, 1650.
(9) Nadasdi, T. T.; Huang, Y.; Stephan, D. W. Inorg. Chem. 1993,
32, 347.
(10) Huang, Y.; Nadasdi, T. T.; Stephan, D. W. J . Am. Chem. Soc.
1994, 116, 5483.
(12) (a) Layer, R. W. Chem. Rev. 1963, 63, 489. (b) Moffett, R. B.
Organic Syntheses; Wiley: New York, 1963; Collect. Vol. 4, p 605. (c)
Friefelder, M. J . Org. Chem. 1966, 31, 3875. (d) Grewe, R.; Hamann,
R.; J acobsen, G.; Nolte, E.; Reicke, K. Ann. Chem. 1953, 581, 85.
(11) Gorsich, R. D. J . Am. Chem. Soc. 1958, 80, 4744.

2322 Organometallics, Vol. 15, No. 9, 1996
Huang et al.
6.35 (d, d, 1H, |J H-H| ) 4.8, 2.2 Hz). 13C{1H} NMR (C6D6, 25
°C): δ 16.26 (br), 16.36, 37.60, 51.14, 93.73, 108.49, 109.17,
111.57, 112.76, 126.45. 31P NMR (C6D6, 25 °C): δ -6.25.
Found: C, 52.88; H, 6.17. Data for 12 are as follows. Method
i: reaction time, 16 h; reaction temp, 25 °C. Yield: 89%. 1H
NMR (CDCl3, 25 °C): δ 1.0-1.8 (m, 20H), 1.97 (d, br, 2H,
|J H-H| ) 14 Hz), 2.08 (m, 2H), 2.33 (s, 3H), 3.54 (d, t, 4H, |J H-H
|
Syn th esis of Cp Ti(O2CMe)3 (7). To a suspension of 3 (85
mg, 0.195 mmol) in THF (3 mL) was added excess acetic acid.
The reaction was stirred for 5 h at 25 °C. The solution became
yellow. The solvent was removed and the residue extracted
into THF and pentane was added to give yellow crystals of 7.
Yield: 86%. 1H NMR (CDCl3, 25 °C): δ 1.93 (s, 9H), 6.45 (s,
5H). 13C{1H} NMR (CDCl3, 25 °C): δ 59.54, 122.87, 189.20.
Anal. Calcd for C11H14O6Ti: C, 45.54; H, 4.86. Found: C,
45.33; H, 4.76.
Syn th esis of [Cp Ti(SCH2CH2CH2S)2][THF H] (8). 1,3-
Propanedithiol (0.016 g, 0.15 mmol) was added to a stirred
suspension of 3 (0.131 g, 0.30 mmol) in THF (3 mL). The
brown-black suspension immediately turned deep red; how-
ever, some dark precipitate remained. The solution was
filtered, and the remaining red solution was concentrated to
1 mL. Orange-red crystals of 8 were formed from a THF/
pentane liquid/vapor diffusion after standing for 4 days.
Yield: 45% (by NMR). Yield of crystalline product: 15%. 1H
NMR (C4D8O, 25 °C): δ 6.13 (s, 5H), 3.48 (m, 4H), 3.02 (m,
4H), 2.54 (m, 2H), 1.79 (m, 2H). 13C{1H} NMR (C4D8O, 25
°C): δ 28.41, 36.72, 113.32.
Syn th esis of Cp Ti(SCH(CP h 2O)CH2CH2S) (9), (MeCp )-
Ti(SCH (CP h 2O)CH 2CH 2S) (10), [Cp Ti(SCH (C6H 10O)-
CH2CH2S)]2 (11), [(MeCp)Ti(SCH(C6H10O)CH2CH2S)]2 (12),
[CpTi(SCH(C7H12O)CH2CH2S)]2 (13), [CpTi(SCH(C10H18O)-
CH2CH 2S)]2 (14), [Cp Ti(SCH (C9H 14O)CH2CH 2S)]2 (15),
a n d [Cp Ti(SCH(C4H9)C(CH3)O)CH2CH2S)]2 (16). These
compounds were prepared in similar fashion; thus, one sample
preparation is described in detail and the major differences
in time, temperature, and solvent are reported. (i) To a
suspension of 3 (85 mg, 0.195 mmol) in THF (3 mL) was added
Ph2CO (70 mg, 0.38 mmol). The reaction was stirred for 5 h
at 25 °C. The reaction was filtered, the solvent removed, and
the residue washed with pentane and extracted into CH2Cl2.
Crystallization was induced by addition of benzene yielding
purple-black product 9 in 92% yield. (ii) An alternative
synthesis of 9 and 11 is described as follows: To a THF
solution (1 mL) of 5 (58 mg, 0.100 mmol) was added Ph2CO
(18 mg, 0.100 mmol). The solution was stirred for 5 min and
the solvent removed. The residue was washed with pentane
and dried in vacuo, and the compound 9 isolated in 90% yield.
Data for 9 are as follows. 1H NMR (C6D6, 25 °C): δ 2.20 (d, d,
) 7, 4.5 Hz), 4.39 (d, d, 2H, |J H-H| ) 11.5, 2.5 Hz), 6.00 (m,
2H), 6.17 (m, 2H), 6.31 (m, 2H), 6.38 (m, 2H). 13C{1H} NMR
(CDCl3, 25 °C): δ 16.77, 21.55, 22.60, 25.85, 31.32, 32.19, 37.80,
38.62, 72.18, 94.20, 113.10, 114.25, 114.6, 114.92, 116.69. Data
for 13 are as follows. Reaction time, 24 h; recrystallized from
CH2Cl2/pentane. Yield: 93% (25 °C, 13a :13b ) 80:20; -78
°C, 13a :13b ) 92:8; from 1H NMR). 13a : 1H NMR (CDCl3,
25 °C): δ 1.06 (d, 6H, |J H-H| ) 6.3 Hz), 1.0-1.9 (m 18H), 1.95,
d, d, br, 2H, |J H-H| ) 12.6, 5.4, 2.0 Hz), 2.20 (d, br, 2H, |J H-H
|
) 13.0 Hz), 3.40 (d, d, d, 2H, |J H-H| ) 12.9, 5.4, 4.5 Hz), 3.97
(d, d, d, 2H, |J H-H| ) 12.9, 8.7, 2.0 Hz), 4.66 (d, d, 2H, |J H-H
|
) 11.7, 1.0 Hz), 6.39 (s, 10H). 13C{1H} NMR (CDCl3, 25 °C):
δ 16.37, 21.93, 26.38, 31.31, 31.57, 32.50, 38.31, 39.24, 68.05,
1
97.41, 114.86. 13b: H NMR (CDCl3, 25 °C): δ 1.01 (d, 6H,
|J H-H| ) 6.3 Hz), 4.50 (d, d, 2H, |J H-H| ) 11.7, 1.0 Hz), 6.38 (s,
10H). 13C{1H} NMR (CDCl3, 25 °C): δ 18.50, 22.89, 26.10,
29.37, 32.50, 33.60, 36.64, 38.76, 71.32, 95.60, 114.90. Anal.
Calcd for C15H22OS2Ti: C, 54.54; H, 6.71. Found: C, 54.27;
H, 6.66. Data for 14 are as follows. Reaction time, 24 h;
reaction temp, -78 °C; recrystallized from CH2Cl2/pentane.
Yield: 83%. 1H NMR (CDCl3, 25 °C): δ 0.90 (d, 6H, |J H-H| )
6.6 Hz), 0.92 (d, 6H, |J H-H| ) 6.6 Hz), 0.99 (d, 6H, |J H-H| ) 6.2
Hz), 1.53, (d, d, d, br, 2H, |J H-H| ) 13.5, 11.4, 5.0 Hz), 1.1-1.7
(m, 14H), 1.95 (d, d, 2H, |J H-H| ) 13.5, 3.0 Hz), 2.23 (d, br,
2H, |J H-H| ) 13.0 Hz), 2.27 (m, 2H), 3.35 (m, 2H) 3.40 (m, 2H),
4.74 (d, br, 2H, |J H-H| ) 11.4 Hz), 6.34 (s, 10H). 13C{1H} NMR
(CDCl3, 25 °C): δ 19.89, 21.65, 22.31, 22.73, 23.83, 28.24, 32.17,
34.93, 38.75, 42.40, 49.29, 73.07, 98.85, 114.92. Anal. Calcd
for C18H28OS2Ti: C, 58.05; H, 7.58. Found: C, 57.98; H, 7.49.
Data for 15 are as follows. Reaction time, 24 h; reaction temp,
-78 °C. The reaction residue was washed with pentane (2 ×
2 mL), and the residual solvent was removed in vacuo to give
15 as an oil. Yield: 80% (-78 °C, 15a :15b:15c ) 70:30:trace;
5 °C, 15a :15b:15c ) 57:36:3; 30 °C, 15a :15b:15c ) 55:5:20;
ratios from 1H NMR). 15a : 1H NMR (CDCl3, 25 °C): δ 0.78
(s, 3H), 1.16 (s, 3H), 1.70-2.30 (m, 8H), 2.95 (t, 1H, |J H-H| )
7.2 Hz), 3.50 (d, d, d, 1H, |J H-H| ) 13.5, 5.4, 3.3 Hz), 3.85 (d,
d, d, d, br, 1H, |J H-H| ) 13.5, 5.4, 3.3 Hz), 4.10 (t, d, 1H, |J H-H
|
) 13.5, 3.1 Hz), 4.70 (d, d, 1H, |J H-H| ) 5.4, 1.8 Hz), 6.48 (s,
5H). 13C{1H} NMR (CDCl3, 25 °C): δ 22.74, 23.70, 26.77,
27.98, 29.31, 34.01, 39.70, 40.69, 52.69, 69.85, 72.19, 101.98,
113.93. 15b: 1H NMR (CDCl3, 25 °C): δ 0.79 (s, 3H), 1.15 (s,
3H), 1.7-2.30 (m, 7H), 2.50 (t, 1H, |J H-H| ) 7.2 Hz), 2.80 (t, d,
1H, |J H-H| ) 12.0, 6.0 Hz), 3.20 (d, d, d, br, 1H, |J H-H| ) 13.5,
5.4, 3.3 Hz), 3.80 (d, d, d, br, 1H, |J H-H| ) 13.5, 5.4, 3.3 Hz),
4.19 (t, d, 1H, |J H-H| ) 13.5, 3.1 Hz), 4.91 (d, d, 1H, |J H-H| )
5.4, 1.8 Hz), 6.52 (s, 5H). 13C{1H} NMR (CDCl3, 25 °C): δ
23.05, 24.42, 26.07, 27.98, 29.75, 35.28, 39.89, 40.90, 51.05,
68.01, 74.02, 102.02,114.05. 15c: 1H NMR (CDCl3, 25 °C): δ
0.96 (s, 6H), 1.23 (s, 6H), 1.0-2.3 (m, 16H), 2.5 (m, 4H), 3.5
(m, 2H), 3.7 (m, 2H), 4.38 (d, d, 2H, |J H-H| ) 10.8, 1.0 Hz)
6.28 (s, 10H). 13C{1H} NMR (CDCl3, 25 °C): δ 24.23, 24.21,
28.64, 28.67, 29.32, 35.35, 39.55, 47.35, 54.30, 60.05, 74.15,
100.76, 114.74. Anal. Calcd for C17H24OS2Ti: C, 57.30; H,
6.79. Found: C, 57.10; H, 6.54. Data for 16 are as follows.
Reaction time, 12 h; reaction temp, -78 °C; recrystallized from
t, br, 1H, |J H-H| ) 15.0, 13.5, 4.8 Hz), 3.40 (d, d, d, 1H, |J H-H
|
) 15.0, 3.0, 1.8 Hz), 3.59 (d, d, d, 1H, |J H-H| ) 13.5, 4.8, 3.0
Hz), 3.84 (t, d, 1H, |J H-H| ) 13.5, 3.0 Hz), 5.95 (d, d, 1H, |J H-H
) 4.8, 1.8 Hz), 6.57, (s, 5H), 7.14, (m, 2H), 7.24 (t, d, 2H, |J H-H
) 7.4 Hz), 7.25 (t, 2H, |J H-H| ) 7.5 Hz), 7.41 (d, br, 2H, |J H-H
|
|
|
) 7.5 Hz), 7.43 (d, br, 2H, |J H-H| ) 7.5 Hz). 13C{1H} NMR
(CDCl3, 25 °C): δ 34.03, 34.72, 67.15, 98.88, 114.87, 124.70,
124.79, 126.42, 126.55, 128.17, 128.31,146.13, 146.31. Anal.
Calcd for C21H20OS2Ti: C, 63.00; H, 5.03. Found: C, 62.80;
H, 4.95. Data for 10 are as follows. Method i: reaction time,
24 h; reaction temp, 25 °C. Yield: 80%. 1H NMR (C6D6, 25
°C): δ 1.92 (s, 3H), 2.25 (d, t, br, 1H, |J H-H| ) 13.5, 5 Hz),
3.16 (m, 1H, |J H-H| ) 13.5 Hz), 3.60 (m, 1H, |J H-H| ) 14 Hz),
4.12 (d, t, 1H, |J H-H| ) 13.5, 3 Hz), 5.67 (m, 1H), 5.90 (m, 1H),
6.05 (m, 1H), 6.85-7.55 (m, 10H). 13C{1H} NMR (C6H6, 25
°C): δ 15.49, 34.84, 65.79, 98.59, 114.09, 114.31, 114.48,
114.87, 125.01, 125.64, 126.35, 126.51, 128.31, 128.39, 129.97,
147.41, 149.88. Data for 11 are as follows. Method i: reaction
time, 5 h; reaction temp, 25 °C. Yield: 95%. Method ii:
reaction time, 5 min; reaction temp, 25 °C; recrystallized from
CH2Cl2/C6H6. Yield: 70%. 1H NMR (CDCl3, 25 °C): δ 1.0-
2.0 (m, 20H), 1.95 (d, br, 2H), 2.14 (d, d, br, 2H, |J H-H| ) 13.2,
5.2 Hz), 3.50 (d, d, d, 2H, |J H-H| ) 13.0, 5.2, 4.0 Hz), 3.70 (d,
d, br, 4H, |J H-H| ) 13.0, 7.2, 3.3 Hz), 4.50 (d, d, 2H, |J H-H| )
11.4, 1.0 Hz), 6.39 (s, 10H). 13C{1H} NMR (CDCl3, 25 °C): δ
21.34, 22.50, 25.70, 31.39, 38.36, 40.38, 40.43, 73.17, 95.29,
114.71. Anal. Calcd for C14H20OS2Ti: C, 53.16; H, 6.37.
1
CH2Cl2/pentane. Yield: 82% (16a :16b ) 66:33, by H NMR).
16a : 1H NMR (CDCl3, 25 °C): δ 0.85 (t, 6H, |J H-H| ) 7.2 Hz),
1.0 (s, 6H), 1.1-1.4 (m, 12H), 1.52 (m, 2H), 2.10 (d, br, 2H,
|J H-H| ) 12.5 Hz), 3.50 (d, br, 2H, |J H-H| ) 13.0 Hz), 3.74 (d,
br, 2H, |J H-H| ) 13.0 Hz), 4.56 (d, br, 2H, |J H-H| ) 11.1 Hz),
6.24 (s, 10H). 13C{1H} NMR (CDCl3, 25 °C): δ 14.22, 22.19,
23.51, 26.06, 32.68, 39.79, 41.37, 70.48, 95.68, 114.37. 16b:11
1H NMR (CDCl3, 25 °C): δ 1.10 (s, 3H), 4.60 (d, br, 2H, |J H-H
|
) 10.0 Hz), 6.33 (s, 10H). 13C{1H} NMR (CDCl3, 25 °C): δ
14.22, 22.19, 25.53, 26.26, 32.28, 40.24, 41.37, 71.23, 96.00,
114.90. Anal. Calcd for C14H22OS2Ti: C, 52.82; H, 6.97.
Found: C, 52.66; H, 6.77.

Thiatitanacyclopropane Complexes
Organometallics, Vol. 15, No. 9, 1996 2323
Syn t h esis of Cp Ti(SCH (P h CH NP h )CH 2CH 2S) (17),
Cp Ti(SCH(P h CHNC6H4OMe)CH2CH2S) (18), Cp Ti(SCH-
((C6H4OMe)CHNP h )CH2CH2S) (19), CpTi(SCH((C6H4OMe)-
CH NC6H 4OMe)CH 2CH 2S) (20), Cp Ti(SCH (P h CH NP r )-
CH 2CH 2S) (21), a n d Cp Ti(SCH (P h CH N(CMe(Na p t h ))-
CH2CH2S) (22). These compounds were prepared in similar
fashion; thus, one sample preparation is described in detail
and the major differences in time and solvent are reported.
To a suspension of 3 (85 mg, 0.195 mmol) in THF (3 mL) was
added PhCHdNPr (56 mg, 0.38 mmol). The reaction was
stirred for 3 days at 25 °C and then filtered. The solvent was
removed and the residue washed with 2 × 1 mL portions of
pentane. Recrystallization of the residue from benzene/
pentane yielded black crystals of 21 in 87% yield. Data for
17 are as follows. Yield: 78% (17a :17b ) 81:19, by 1H NMR).
17a : 1H NMR (C6D6, 25 °C): δ 2.02 (t, d, d, 1H, |J H-H| ) 13.8,
5.4, 3.0 Hz), 2.43 (d, d, br, 1H, |J H-H| ) 13.8, 5.4 Hz), 3.66 (d,
d, br, 1H, |J H-H| ) 13.8, 5.4 Hz), 4.25 (t, d, 1H, |J H-H| ) 13.8,
5.4 Hz), 4.79 (t, br, 1H, |J H-H| ) 5.4 Hz), 6.04 (s, 5H), 5.78 (d,
1H, |J H-H| ) 5.4 Hz) 6.4-7.3 (m, 10H). 13C{1H} NMR (C6D6,
25 °C): δ 32.67, 36.81, 48.35, 75.15, 114.03, 122.31, 126.91,
127.04, 127.80, 128.91, 129.29, 144.38, 151.94. 17b: 1H NMR
(C6D6, 25 °C): δ 2.20 (t, d, br, 1H, |J H-H| ) 13.8, 15.4 Hz),
113.47, 114.73, 124.15, 127.87, 128.98, 134.20, 145.31, 155.50,
158.05. 20b: 1H NMR (CDCl3, 25 °C): δ 2.31 (t, d, 1H, |J H-H
|
) 13.8 Hz, |J H-H| ) 3.6 Hz), 3.2 (d, br, 1H, |J H-H| ) 13.8 Hz),
3.7 (m, 1H), 3.65 (s, 3H), 3.67 (s, 3H), 3.76 (m, 1H), 4.65 (d,
br, 1H, |J H-H| ) 5.4 Hz), 5.03 (br, 1H), 6.56 (s, 5H), 6.42, (d,
2H, |J H-H| ) 8.7 Hz), 6.64 (d, 2H, |J H-H| ) 8.7 Hz), 6.89 (d,
2H, |J H-H| ) 8.7 Hz), 7.15 (d, 2H, |J H-H| ) 8.7 Hz). 13C{1H}
NMR (CDCl3, 25 °C): δ 34.75, 40.90, 51.37, 55.20, 55.41, 76.14,
113.99, 114.34, 124.30, 128.42, 129.02, 135.01, 145.42, 155.30,
158.08. Anal. Calcd for C23H25NO2S2Ti: C, 60.13; H, 5.48;
N, 3.05. Found: C, 59.86; H, 5.23; N, 2.86. 21a : 3 days, yield
87%. Crystals of 21b were isolated from recrystallizations of
21a . 21a : 1H NMR (C6D6, 25 °C): δ 0.60 (t, 3H, |J H-H| ) 7.2
Hz), 1.2 (m, 2H), 2.37 (t, d, br, 1H, |J H-H| ) 13.5, 3.6 Hz), 2.42
(q, 1H, |J H-H| ) 7.5 Hz), 2.90 (d, d, d, br, 1H, |J H-H| ) 13.5,
7.2, 5.7 Hz), 2.94 (q, 1H, |J H-H| ) 7.5 Hz), 3.76 (d, d, d, 1H,
|J H-H| ) 13.5, 7.2, 3.6 Hz), 3.91 (t, d, 1H, |J H-H| ) 13.5, 3.3
Hz), 4.42 (d, 1H, |J H-H| ) 5.7 Hz), 4.77 (br, 1H), 6.11 (s, 5H),
7.64 (br, 2H), 7.41 (br, 3H). 13C{1H} NMR (CDCl3, 25 °C): δ
11.90, 24.36, 32.77, 39.56, 49.36, 59.80, 74.46, 113.06, 127.12,
127.80, 128.10, 143.44. Anal. Calcd for C18H23NS2Ti: C,
59.17; H, 6.34; N, 3.83. Found: C, 58.90; H, 6.20; N, 3.75.
21b: 1H NMR (C6D6, 25 °C): δ 0.51 (t, 6H, |J H-H| ) 6.2 Hz),
1.0-1.4 (m, 4H), 1.55 (m, 2H), 2.39 (m, 2H), 3.0 (t, d, 2H, |J H-H
|
2.60 (d, d, br, 1H, |J H-H| ) 13.8, 5.4 Hz), 3.50 (d, br, 1H, |J H-H
|
) 13.0, 3.6 Hz), 3.40 (m, 4H), 3.60 (d, br, 2H, |J H-H| ) 13.0
Hz), 4.47 (d, 2H, |J H-H| ) 11.4 Hz), 4.70 (d, d, d, 2H, |J H-H| )
13.0, 11.4, 3.6 Hz), 6.18 (s, 10H), 7.2 (m, 10H). 13C{1H} NMR
(CDCl3, 25 °C): δ 11.92, 21.69, 33.89, 37.39, 58.65, 59.04, 81.64,
113.50, 127.70, 128.42, 129.55, 143.44. Data for 27 are as
follows. Reaction time: 6 days. The reaction residue was
washed with pentane (2 × 2 mL), and the residual solvent was
removed in vacuo. Yield: 83% (22a :22b ) 50:50, by 1H NMR).
22a : 1H NMR (C6D6, 25 °C): δ 1.11 (d, 6H, |J H-H| ) 6.6 Hz),
1.85 (d, d, d, br, 2H, |J H-H| ) 14.7, 13.0, 4.8 Hz), 2.34 (d, d, d,
br, 2H, |J H-H| ) 14.7, 5.4, 4.8 Hz), 3.40 (d, d, 2H, |J H-H| )
13.0, 4.8 Hz), 3.60 (t, d, br, 2H, |J H-H| ) 13.0, 4.8 Hz), 4.26 (d,
br, 2H, |J H-H| ) 5.4 Hz), 4.65 (q, 2H, |J H-H| ) 6.6 Hz), 4.71
(m, br, 2H), 6.32 (s, 10H), 7.0-8.1(m, br, 24H). 13C{1H} NMR
(C6D6, 25 °C): δ 24.87, 31.28, 37.89, 49.82, 57.25, 73.37, 112.80,
124.03, 125.77, 125.65, 125.89, 128.83, 131.03, 133.99, 141.11,
145.02. 22b: 1H NMR (C6D6, 25 °C): δ 1.35 (d, 6H, |J H-H| )
6.6 Hz), 2.07 (d, d, d, br, 2H, |J H-H| ) 14.7, 13.0, 4.8 Hz), 2.95
(d, d, d, d, 2H, |J H-H| ) 14.7, 5.4, 4.8, 3.0 Hz), 3.98 (d, d, d,
2H, |J H-H| ) 13.0, 4.8, 3.0 Hz), 4.34 (t, d, 2H, |J H-H| ) 13.0,
3.0 Hz), 4.43 (d, br, 2H, |J H-H| ) 5.4 Hz), 4.85 (q, 2H, |J H-H| )
6.6 Hz), 5.16 (m, br, 2H), 5.48 (s, 10H), 7.0-8.1 (m, br, 24H).
13C{H} NMR (C6D6, 25 °C): δ 24.87, 34.89, 38.54, 50.50, 59.68,
74.41, 112.74, 123.80, 125.48, 125.65, 126.42, 128.41, 131.55,
134.10, 140.40, 143.17 (other peaks between 127 and 128 ppm).
Anal. Calcd for C27H27NS2Ti: C, 67.91; H, 5.70; N, 2.93.
Found: C, 67.69; H, 5.55; N, 2.70.
) 13.8 Hz), 3.85 (t, br, 1H, |J H-H| ) 13.8 Hz), 4.48 (d, br, 1H,
|J H-H| ) 5.4 Hz), 4.87 (m, br, 1H), 6.26 (s, 5H), 6.4-7.3 (m,
10H). 13C{1H} NMR (C6D6, 25 C): δ 31.69, 37.52, 51.60, 76.75,
113.97, 122.18, 126.49, 127.60, 127.97, 128.11, 128.67, 142.95,
152.36. Anal. Calcd for C21H21NS2Ti: C, 63.15; H, 5.30.
Found: C, 63.07; H, 5.19. Data for 18 are as follows. Yield:
1
86% (18a :18b ) 65:35, by H NMR). 18a : 1H NMR (CDCl3,
25 °C): δ 2.01 (t, d, 1H, |J H-H| ) 13.8, 3.6 Hz), 2.60 (d, t, br,
1H, |J H-H| ) 13.8, 5.4 Hz), 3.40 (d, br, 1H, |J H-H| ) 13.8 Hz),
3.68 (s, 3H), 3.80 (m, 1H), 4.90 (t, br, 1H, |J H-H| ) 5.4 Hz),
6.09 (d, 1H, |J H-H| ) 5.4 Hz), 6.32 (s, 5H), 6.41 (d, 2H, |J H-H
|
) 8.6 Hz), 6.63 (d, 2H, |J H-H| ) 8.6 Hz), 7.1-7.5 (m, 5H). 13C-
{1H} NMR (CDCl3, 25 °C): δ 32.60, 36.52, 48.27, 55.05, 75.53,
113.47, 114.17, 126.86, 127.35, 127.88, 128.43, 142.16, 145.37,
155.53. 18b: 1H NMR (CDCl3, 25 °C): δ 2.32 (t, d, 1H, |J H-H
|
) 13.8 Hz, |J H-H| ) 3.9 Hz), 3.15 (d, br, 1H, |J H-H| ) 13.8 Hz),
3.61 (m, 1H), 3.67 (s, 3H), 3.8 (m, 1H), 4.69 (d, br, 1H, |J H-H
|
) 5.4 Hz), 5.69 (br, 1H), 6.58 (s, 5H), 6.40 (d, 2H, |J H-H| ) 8.6
Hz), 6.63 (d, 2H, |J H-H| ) 8.6 Hz), 7.1-7.5 (m, 5H). 13C{1H}
NMR (CDCl3, 25 °C): δ 35.42, 38.55, 51.17, 55.05, 71.30,
113.99, 114.32, 126.73, 127.58, 127.80, 128.11, 143.98, 145.24,
155.53. Anal. Calcd for C22H23NOS2Ti: C, 61.53; H, 5.40; N,
3.26. Found: C, 61.21; H, 5.26; N, 3.12. Data for 19 are as
follows. Yield: 80% (19a :19b ) 77:23, by 1H NMR). 19a : 1H
NMR (CDCl3, 25 °C): δ 2.02 (t, d, 1H, |J H-H| ) 13.8, 3.6 Hz),
2.65 (d, t, br, 1H, |J H-H| ) 13.8, 5.4 Hz), 3.40 (m, 1H), 3.71 (s,
3H), 4.15 (t, d, 1H, |J H-H| ) 13.8, 3.6 Hz), 4.89 (t, br, 1H, |J H-H
|
) 5.4 Hz), 6.07 (d, 1H, |J H-H| ) 5.4 Hz), 6.30 (s, 5H), 6.70 (d,
2H, |J H-H| ) 8.6 Hz), 7.01 (d, 2H, |J H-H| ) 8.6 Hz), 6.8-7.1
(m, 5H). 13C{1H} NMR (CDCl3, 25 °C): δ 32.53, 36.67, 48.51,
55.20, 74.08, 113.51, 114.89, 127.77, 127.97, 128.65, 128.81,
134.09, 151.32, 158.11. 19b: 1H NMR (CDCl3, 25 °C): δ 2.30
(t, br, 1H, |J H-H| ) 13.8 Hz), 3.2 (m, 1H), 3.7 (m, 1H), 3.72 (s,
3H), 3.85 (m, 1H), 4.69 (d, br, 1H, |J H-H| ) 5.4 Hz), 5.08 (br,
1H), 6.60 (s, 5H), 6.89 (d, 2H, |J H-H| ) 8.6 Hz), 7.12 (d, 2H,
|J H-H| ) 8.6 Hz), 6.8-7.1 (m, 5H). 13C{1H} NMR (CDCl3, 25
°C): δ 35.85, 38.26, 51.86, 55.20, 76.14, 113.92, 114.45, 122.47,
127.90, 128.00, 128.77, 135.76, 151.52, 158.59. Anal. Calcd
for C22H23NOS2Ti: C, 61.53; H, 5.40; N, 3.26. Found: C, 61.16;
H, 5.34; N, 3.22. Data for 20 are as follows. Yield: 83% (20a :
Syn th esis of Cp Ti(SC(P h CNH)CH2CH2S) (23), Cp Ti-
(SC(C4H 9CNH )CH 2CH 2S) (24), Cp Ti(SC(MeSCNH )-
CH 2CH 2S) (25), Cp Ti(SC(CyNH CNCy)CH 2CH 2S) (26),
CpTi(SC(P h NCO)CH2CH2S)TiCp(SCH2CH2CH2S) (27), an d
Cp Ti(SC(P h NHCS)CH2CH2S) (28). These compounds were
prepared in similar fashion; thus, one sample preparation is
described in detail and the major differences in time and
solvent are reported. To a suspension of 1 (85 mg, 0.195 mmol)
in THF (1 mL) was added PhCN (39 mg, 0.38 mmol). The
reaction was stirred overnight at 25 °C and then filtered. The
solvent was removed and the residue extracted into CH2Cl2.
Crystallization of the residue was induced by addition of
benzene yielding purple-black crystals of 23 in 89% yield. Data
for 23 are as follows. 1H NMR (C6D6, 25 °C): δ 2.26 (t, br,
1H, |J H-H| ) 12.6 Hz), 2.40 (m, 1H), 2.57 (m, 1H), 3.60 (d, d,
br, 1H, |J H-H| ) 12.6, 6.0 Hz), 6.17 (s, 5H), 7.15 (m, 3H), 7.32
(d, d, 2H, |J H-H| ) 6.3, 1.5 Hz), 7.8 (m, 1H). 13C{1H} NMR
(CDCl3, 25 °C): δ 34.96, 40.91, 98.02, 110.63, 127.07, 128.30,
129.32, 136.61, 150.90. Anal. Calcd for C15H15NS2Ti: C,
56.08; H, 4.71; N, 4.36. Found: C, 55.91; H, 4.60; N, 4.16.
Data for 24 are as follows. Reaction time: 2 days. Yield: 57%.
1
20b ) 65:35, by H NMR). 20a : 1H NMR (CDCl3, 25 °C): δ
2.02 (t, d, 1H, |J H-H| ) 13.8, 3.6 Hz), 2.63 (d, t, br, 1H, |J H-H
|
) 13.8, 5.4 Hz), 3.7 (m, 1H), 3.68 (s, 3H), 3.71 (s, 3H), 4.08 (t,
br, 1H, |J H-H| ) 13.8, 3.6 Hz), 4.87 (t, br, 1H, |J H-H| ) 5.4
Hz), 6.04 (d, 1H, |J H-H| ) 5.4 Hz), 6.31, (s, 5H), 6.41, (d, 2H,
|J H-H| ) 8.7 Hz), 6.64 (d, 2H, |J H-H| ) 8.7 Hz), 6.70 (d, 2H,
|J H-H| ) 8.7 Hz), 6.89 (d, 2H, |J H-H| ) 8.7 Hz). 13C{1H} NMR
(CDCl3, 25 °C): δ 32.64, 37.55, 48.29, 55.17, 55.50, 75.01,

2324 Organometallics, Vol. 15, No. 9, 1996
Huang et al.
2
1H NMR (C6D6, 25 °C): δ 0.86 (t, 3H, |J H-H| ) 6.9 Hz), 1.2-
1.4 (m, 4H), 1.5 (m, 2H), 2.30 (t, d, 1H, |J H-H| ) 12.6, 4.0 Hz),
puter with remote X-terminals. The reflections with Fo
>
2
3σFo were used in the refinement. Empirical absorption
corrections were applied to the data sets in one of two ways;
either a correction was applied on the basis of ψ-scan data or
the program DIFABS was employed at the point of a com-
pletely isotropic refinement.
2.65 (t, d, 1H, |J H-H| ) 12.6, 6.0 Hz), 2.93 (d, d, br, 1H, |J H-H
|
) 12.9, 6.0 Hz), 3.42 (d, d, br, 1H, |J H-H| ) 12.6, 4.0 Hz), 4.0
(m, 1H), 6.15 (s, 5H) . 13C{1H} NMR (C6D6, 25 °C): δ 14.07,
23.31, 25.05, 31.65, 37.51, 41.02, 108.02, 111.18,159.80. Anal.
Calcd for C13H19NS2Ti: C, 51.82; H, 6.36; N, 4.65. Found: C,
51.65; H, 6.20; N, 4.55. Data for 25 are as follows. Reaction
time: 12 h; recrystallized from CH2Cl2/pentane. Yield: 85%.
1H NMR (C6D6, 25 °C): δ 2.29 (d, 3H, |J H-H| ) 5.4), 2.54 (t, d,
1H, |J H-H| ) 13.5, 7.5 Hz), 2.95 (t, d, 1H, |J H-H| ) 13.5, 5.8
Hz), 3.08 (d, d, br, 1H, |J H-H| ) 13.5, 5.8 Hz), 3.28 (d, d, 1H,
|J H-H| ) 14.4, 5.8 Hz), 4.3 (m, br, 1H), 6.19 (s, 5H). 13C{1H}
NMR (C6D6, 25 °C): δ 29.94, 32.24, 42.18, 105.60, 109.82,
167.04. Anal. Calcd for C10H13NS3Ti: C, 41.24; H, 4.50; N,
4.81. Found: C, 41.09; H, 4.39; N, 4.78. Data for 26 are as
follows. Reaction time: 12 h; recrystallized from THF/pentane.
Yield: 93%. 1H NMR (C6D6, 25 °C): δ 0.9-2.20 (m, 20H), 2.52
(t, d, 1H, |J H-H| ) 13.0, 6.0 Hz), 3.08 (m, br, 1H), 3.15 (m, 1H),
Str u ctu r e Solu tion a n d Refin em en t. Non-hydrogen
atomic scattering factors were taken from the literature
tabulations.13,14 The Ti atom positions were determined using
direct methods by employing either the SHELX-86 or MITH-
RIL direct methods routines. In each case, the remaining non-
hydrogen atoms were located from successive difference Fou-
rier map calculations. The refinements were carried out by
using full-matrix least-squares techniques on F, minimizing
the function w(|Fo| - |Fc|)2, where the weight w is defined as
4Fo2/2σ(Fo2) and Fo and Fc are the observed and calculated
structure factor amplitudes. In the final cycles of refinement
all heavy atoms were assigned anisotropic temperature factors.
The number of carbon atoms assigned anisotropic thermal
parameters varied among the structures and was set so as to
maintain a reasonable data:variable ratio in each case. In the
cases of 8, 9, 11, 19, 21, and 27 solvent molecules were also
located and refined. In some cases cyclopentadienyl and
phenyl rings were modeled as rigid groups with a C-C bond
length of 1.40 Å. This was done in cases where it was
necessary to maintain an appropriate data:variable ratio.
Hydrogen atom positions were calculated and allowed to ride
on the carbon to which they are bonded assuming a C-H bond
length of 0.95 Å. Hydrogen atom temperature factors were
fixed at 1.10 times the isotropic temperature factor of the
carbon atom to which they are bonded. In all cases the
hydrogen atom contributions were calculated but not refined.
The final values of R and Rw are given in Table 1. In all cases,
the residual electron densities were of no chemical significance.
The following data have been deposited as Supporting Infor-
mation: positional parameters, thermal parameters, hydrogen
atom parameters, and selected bond distances and angles.
Kin etic Stu d ies. The reactions of thiatitanacyclopropane
4 with benzophenone and cyclohexanone were monitored by
1H NMR spectroscopy at several initial concentrations of 4
using excess ketone in all cases. Concentrations were deter-
mined via integration versus an internal standard. Plots of
concentrations versus time were analyzed and the rate con-
stants and order determined in the standard fashion.
Molecu la r Or bita l Ca lcu la tion s.15 Extended Huckel
calculations were performed and visualized by employing the
Cache Software system operating on a Power Mac 7100
computer. Initial coordinates and geometric parameters were
taken from X-ray data.
3.33 (t, d, 1H, |J H-H| ) 13.0, 5.7 Hz), 3.40 (d, d, d, 1H, |J H-H
|
) 13.0, 6.0, 3.0 Hz), 3.45 (m, 1H), 3.65 (d, d, d, 1H, |J H-H| )
14.0, 5.7, 3.0 Hz), 6.43 (s, 5H). 13C{1H} NMR (C6D6, 25 °C):
δ 24.92, 25.43, 25.71, 26.10, 33.80, 35.16, 35.50, 42.81, 54.28,
62.07, 92.64, 109.30, 154.01. Anal. Calcd for C21H32N2S2Ti:
C, 59.42; H, 7.60; N, 6.60. Found: C, 59.35; H, 7.55; N, 6.45.
Data for 27 are as follows. Reaction time: 12 h. Reaction
temp: 25 °C. The reaction residue was washed with pentane
(2 × 2 mL), and the residual solvent was removed in vacuo to
solid 27, which was recrystallized from benzene/pentane.
Yield: 75%. 1H NMR (C6D6, 25 °C): δ 2.50 (m, 2H), 3.0 (m,
2H), 3.22 (d, d, br, 1H, |J H-H| ) 14.1, 12.6 Hz), 3.44 (d, d, br,
1H, |J H-H| ) 14.1, 12.6 Hz), 3.69 (d, d, br, 1H, |J H-H| ) 14.1,
5.0 Hz), 3.72 (d, d, br, 1H, |J H-H| ) 14.1, 4.2, 2.0 Hz), 3.93 (m,
2H), 5.96 (s, 5H), 6.26 (s, 5H), 6.70 (d, br, 1H, |J H-H| ) 7.2
Hz), 6.76 (t, 2H, |J H-H| ) 7.2 Hz), 6.90 (t, 2H, |J H-H| ) 7.2
Hz). 13C{H} NMR (C6D6, 25 °C): δ 31.90, 34.77 , 37.51, 38.27,
39.58, 102.41, 110.57, 113.86, 123.84, 124.43,128.96, 147.10,
152.40. Anal. Calcd for C23H26ONS4Ti2: C, 49.64; H, 4.71;
N, 2.52. Found: C, 49.51; H, 4.61; N, 2.43. Data for 28 are
as follows. Reaction time: 18 h. Yield: 86%. 1H NMR (C6D6,
25 °C): δ 2.26 (t, d, 1H, |J H-H| ) 13.0, 7.2 Hz), 3.0 (d, d, br,
1H, |J H-H| ) 13.0, 7.2 Hz), 3.27 (t, d, 1H, |J H-H| ) 13.0, 5.4
Hz), 3.50 (d, d, br, 1H, |J H-H| ) 13.0, 5.4 Hz), 6.17 (s, 5H),
6.63 (d, br, 1H, |J H-H| ) 7.5 Hz), 6.69 (br, 1H), 6.92 (t, 2H,
|J H-H| ) 7.5 Hz), 7.03 (d, 2H, br, |J H-H| ) 7.5 Hz). 13C{1H}
NMR (C6D6, 25 °C): δ 31.83, 43.76, 110.28, 111.70, 122.62,
124.26, 129.01, 140.42, 160.09. Anal. Calcd for C15H15NS3Ti:
C, 50.84; H, 4.55; N, 3.95. Found: C, 50.75; H, 4.43; N, 3.78.
X-r a y Da ta Collection a n d Red u ction . X-ray-quality
crystals were obtained directly from the preparations as
described above. The crystals were manipulated and mounted
in capillaries in a glovebox, thus maintaining a dry, O2-free
environment for each crystal. Diffraction experiments were
performed on a Rigaku AFC6 diffractometer equipped with
graphite-monochromatized Mo KR radiation. The initial
orientation matrices were obtained from 20 machine-centered
reflections selected by an automated peak search routine.
These data were used to determine the crystal systems.
Automated Laue system check routines around each axis were
consistent with the crystal systems reported in Table 1.
Ultimately, 25 reflections (20° < 2θ < 25°) were used to obtain
the final lattice parameters and the orientation matrices.
Machine parameters, crystal data, and data collection param-
eters are summarized in Table 1. The observed extinctions
were consistent with the space group given in Table 1. The
data sets were collected in one shell (4.5° < 2θ < 50.0°), and
three standard reflections were recorded every 197 reflections.
The intensities of the standards showed no statistically
significant change over the duration of the data collection. The
data were processed using the TEXSAN crystal solution
package operating on a VAX workstation 3520 or employing
the TEXSAN package operating on an SGI mainframe com-
Resu lts a n d Discu ssion
The reaction of 1 with MeLi proceeds smoothly at -78
°C to give on subsequent workup the microcrystalline
product [CpTi(SCHCH2CH2S)]2 (3) as confirmed by
NMR and X-ray diffraction studies. The compound 3
and its analog [(MeCp)Ti(SCHCH2CH2S)]2 (4) are also
prepared from the reaction of 1 with either AlMe3 or
t-BuLi. Both compounds are centrosymmetric dimers
in the solid state (Figure 1) in which the two Ti centers
are bridged by two thiolato-sulfur atoms. A second
sulfur atom and the carbon alpha to it and a cyclopen-
tadienyl ring complete the coordination spheres of the
(13) (a) Cromer, D. T.; Mann, J . B. Acta Crystallogr., Sect. A: Cryst.
Phys., Theor. Gen. Crystallogr. 1968, A24, 324. (b) Ibid. 1968, A24,
390.
(14) Cromer, D. T.; Waber, J . T. International Tables for X-ray
Crystallography; Knoch Press: Birmingham, England, 1974.
(15) CaChe Worksystem software is an integrated modeling, mo-
lecular mechanics, and molecular orbital computational software
package and is a product of CaChe Scientific Inc.

Thiatitanacyclopropane Complexes
Organometallics, Vol. 15, No. 9, 1996 2325

2326 Organometallics, Vol. 15, No. 9, 1996
Huang et al.
F igu r e 2. ORTEP drawing of 7, with 30% thermal
ellipsoids shown. Hydrogen atoms are omitted for clarity.
Distances and angles: Ti-O(1) 2.107(7) Å, Ti-O(2) 2.247-
(7) Å, Ti-O(3) 2.153(6) Å, Ti-O(4) 2.094(6) Å, Ti-O(5)
2.115(7) Å, Ti-O(6) 2.205(7) Å, O(1)-Ti-O(2) 59.6(3)°,
O(3)-Ti-O(4) 61.4(2)°, O(5)-Ti-O(6) 60.2(2)°.
Sch em e 1
F igu r e 1. ORTEP drawings of (a) 3 and (b) 4, with 30%
thermal ellipsoids shown. Hydrogen atoms are omitted for
clarity. 3: Ti-S(1) 2.442(2) Å, Ti-S(1)′ 2.504(2) Å, Ti-S(2)
2.289(2) Å, Ti-C(8) 2.149(5) Å, S(1)-Ti-S(1)′ 92.58(5)°,
S(1)-Ti-S(2) 98.77(5)°, S(1)-Ti-S(2)′ 86.12(6)°, S(2)-Ti-
C(8) 46.1(1)°, Ti-S(1)-Ti′ 87.42(5)°. 4: Ti-S(1) 2.467(3)
Å, Ti-S(1)′ 2.493(3) Å, Ti-S(2) 2.284(4) Å, Ti-C(9) 2.16-
(1) Å, S(1)-Ti-S(1)′ 91.4(1)°, S(1)-Ti-S(2) 98.6(1)°, S(1)-
Ti-S(2)′ 85.1(1)°, S(2)-Ti-C(9) 47.7(3)°, Ti-S(1)-Ti′ 88.6-
(1)°.
Sch em e 2
Ti centers. The crystallographically imposed center of
symmetry dictates a transoid disposition of the cyclo-
pentadienyl rings relative to the Ti2S2 core. The bridg-
ing Ti-S distances in 3 range from 2.442(2) to 2.504(2)
Å, which is comparable to those seen in the Ti thiolate
9
dimer [CpTiCl(SCH2CH2S)]2 and the heterometallic
complexes [(Cp2Ti(SCH2CH2CH2S)2Ag]+ and [Cp2Ti-
((SCH2CH2SCH2)2CH2)Cu]+.16,17 The Lewis acidity of
the Ti centers in both 3 and 4 results in comparatively
short terminal Ti-S (3, 2.289(2) Å; 4, 2.284(4) Å) and
Ti-RC (3, 2.149(5) Å; 4, 2.16(1) Å) distances while the
ring strain in the thiatitanacyclopropane is evidenced
by the S-Ti-C angles (3, 46.1(1)°; 4, 47.7(3)°).
The mechanism of formation of 3 and 4 could, in
principle, be either via â-hydrogen elimination or â-hy-
drogen abstraction. Attempts to slow the reaction at
low temperature in order to observe alkylated interme-
diates were unsuccessful. It is noteworthy that Buch-
wald et al. confirmed a concerted four-center cyclomet-
alation process is operative in the formation of thio-
formaldehyde derivatives of zirconocene.6
recovered upon attempts to isolate these adducts. This
indicates equilibria govern the formation of these mono-
metallic species from the corresponding dimers (Scheme
1).
Acid olysis. Compound 3 reacts rapidly with protic
reagents. Reaction with HCl cannot be easily con-
trolled, and thus hydrolysis of the Ti-C and Ti-S bonds
occurs rapidly, yielding CpTiCl3. Similarly, addition of
acetic acid to 3 yields the triacetate derivative CpTi-
(O2CMe)3 (7) as confirmed by crystallography (Figure
2). Controlled acidolysis in which the Ti-S bonds were
not severed was achieved in the reactions of 3 with
thiols (Scheme 2). Reaction of 3 with 1 equiv of
benzenethiol gave the known Ti species CpTi(SCH2CH2-
CH2S)(SPh) in quantitative yield (1H NMR),9 while the
similar reaction with propanedithiol gave the salt
H+[CpTi(SCH2CH2CH2S)2]-‚THF (8). The nature of 8
was also confirmed crystallographically (Figure 3). We
have previously described polymeric sodium salts con-
taining the anion of 8.18 The formation of these
Compounds 3 and 4 are readily cleaved in solution
in the presence of PMe3 affording Cp†Ti(SCHCH2CH2S)-
(PMe3) (Cp† ) Cp (5), MeCp (6)). However, 3 and 4 are
(16) Huang, Y.; Nadasdi, T. T.; Drake, R. J .; Stephan, D. W. Inorg.
Chem. 1993, 32, 3022.
(17) Nadasdi, T. T.; Stephan, D. W. Organometallics 1992, 11, 116.

Thiatitanacyclopropane Complexes
Organometallics, Vol. 15, No. 9, 1996 2327
F igu r e 3. ORTEP drawing of anion of 8, with 30% thermal
ellipsoids shown. Hydrogen atoms are omitted for clarity.
Distances and angles: Ti-S(1) 2.469(5) Å, Ti-S(2) 2.378-
(5) Å, Ti-S(3) 2.448(5) Å, Ti-S(4) 2.383(5) Å, S(1)-Ti-
S(2) 84.1(2)°, S(3)-Ti-S(4) 86.4(2)°, S(1)-Ti-S(4) 79.8(2)°,
S(2)-Ti-S(3) 86.4(2)°.
F igu r e 4. ORTEP drawing of 9, with 30% thermal
ellipsoids shown. Hydrogen atoms are omitted for clarity.
Distances and angles: Ti-S(1) 2.301(1) Å, Ti-S(2) 2.299-
(1) Å, Ti-O(1) 1.820(3) Å, S(1)-Ti-S(2) 99.91(5)°, S(1)-
Ti-O(1) 99.5(1)°, S(2)-Ti-O(1) 87.73(9)°.
Sch em e 3
products of acidolysis suggests considerable nucleophilic
character must be attributed to the C atom of the
thiatitanacyclopropane fragment while the facile elec-
trophilic attack at sulfur is similar to that described for
Zr-thioaldehyde derivatives.6,7
F igu r e 5. (a) NMR data used to distinguish monomeric
from dimeric complexes. (b) NOE observed for 13. Note:
partial structures are shown.
Rea ction s w ith Keton es. The reactions of 3 with
a variety of ketones are summarized in Scheme 3. The
reactions of 3 and 4 with benzophenone proceed smoothly
and quantitatively to give the products Cp†Ti(SCH-
(CPh2O)CH2CH2S) (Cp† ) Cp (9); MeCp (10)) in 90%
and 80% isolated yields, respectively. Coupling of the
methine protons to the adjacent methylene protons is
consistent with an equatorial positioning of the methine
protons in six-membered rings of pseudo-chair confor-
mation and, thus, mononuclear complexes. A crystal-
lographic study of 9 (Figure 4) confirmed the pseudo-
three-legged piano stool geometry in which the alkoxy-
carbon atom (C9) adopts an axial position relative to
the six-membered ring formed by chelation of the
dithiolate to Ti.
with mononuclear species, which suggests a dimeric
formulation, i.e. [Cp†Ti(SCH(C6H10O)CH2CH2S)]2 (Cp†
) Cp (11); MeCp (12)). In the case of 11 this was
subsequently confirmed crystallographically (Figure 6).
Two thiolate sulfur atoms bridge the Ti centers; thus,
two tridentate S2O ligands span the two metals. The
cyclopentadienyl rings adopt a cisoid disposition relative
to the Ti2S2 core in contrast to 3. The geometries about
the Ti atoms are best described as “four-legged piano
stools” in which two of the legs are shared.
Reactions of 3 with unsymmetrical ketones result in
diastereomeric products; for example, 2-methylcyclo-
hexanone and menthone yield the dimeric products
[CpTi(SCH(C7H12O)CH2CH2S)]2 (13) and [CpTi(SCH-
(C10H18O)CH2CH2S)]2 (14), respectively. In the former
case, two isomers, 13a ,b, are formed in 80:20 and 92:8
ratios when the reaction is performed at 25 and -78
°C, respectively. NOE experiments indicate that the
major isomer (13a ) has the single methyl substituent
oriented away from the cyclopentadienyl ring while the
orientation is reversed in the minor isomer (13b) (Figure
5b). NMR and X-ray data (Figure 7) confirm the
formation of 14 proceeds with complete diastereoselec-
tivity. The general structural features of 14 are similar
In the analogous reactions of 3 and 4 with cyclohex-
anone, products 11 and 12 are also are derived from
1
insertion of ketone into the Ti-C bond. However, H
NMR data revealed couplings of the methine proton to
the adjacent methylene protons of 11.4 and 1.0 Hz,
respectively (Figure 5a). These data are consistent with
an axial disposition of the methine proton relative to
the six-membered chelate ring formed by the dithiolate
moiety. This orientation is not geometrically compatible
(18) Nadasdi, T. T.; Stephan, D. W. Inorg. Chem. 1994, 33, 1532.

2328 Organometallics, Vol. 15, No. 9, 1996
Huang et al.
F igu r e 6. ORTEP drawing of 11, with 30% thermal
ellipsoids shown. Hydrogen atoms are omitted for clarity.
Distances and angles: Ti(1)-S(1) 2.401(9) Å, Ti(1)-S(2)
2.513(9) Å, Ti(1)-S(4) 2.564(8) Å, Ti(1)-O(1) 1.84(2) Å, Ti-
(2)-S(2) 2.590(9) Å, Ti(2)-S(3) 2.393(9) Å, Ti(2)-S(4)
2.516(9) Å, Ti(2)-O(2) 1.81(2) Å, S(1)-Ti(1)-S(2) 82.0(3)°,
O(1)-Ti(1)-S(4) 76.7(5)°, S(3)-Ti(2)-S(4) 82.2(3)°, O(2)-
Ti(2)-S(2) 76.2(6)°, Ti(1)-S(2)-Ti(2) 104.5(3)°, Ti(1)-S(4)-
Ti(2) 105.2(3)°.
F igu r e 9. ORTEP drawing of 19, with 30% thermal
ellipsoids shown. Hydrogen atoms are omitted for clarity.
Distances and angles: Ti-S(1) 2.306(4) Å, Ti-S(2) 2.280-
(4) Å, Ti-N(1) 1.939(9) Å, S(1)-Ti-S(2) 102.3(2)°, S(1)-
Ti-N(1) 101.8(3)°, S(2)-Ti-N(1) 91.9(3)°.
Sch em e 4
F igu r e 7. ORTEP drawing of 14, with 30% thermal
ellipsoids shown. Hydrogen atoms are omitted for clarity.
Distances and angles: Ti(1)-S(1) 2.390(3) Å, Ti(1)-S(2)
2.534(3) Å, Ti(1)-S(4) 2.569(3) Å, Ti(1)-O(2) 1.826(7) Å,
Ti(2)-S(2) 2.588(3) Å, Ti(2)-S(3) 2.402(4) Å, Ti(2)-S(4)
2.519(3) Å, Ti(2)-O(1) 1.827(6) Å, S(1)-Ti(1)-S(2) 81.5-
(1)°, O(2)-Ti(1)-S(4) 77.9(2)°, S(3)-Ti(2)-S(4) 81.3(1)°,
O(1)-Ti(2)-S(2) 77.3(2)°, Ti(1)-S(2)-Ti(2) 105.2(1)°, Ti-
(1)-S(4)-Ti(2) 106.3(1)°.
indicates that the monomeric and dimeric products are
not interconvertible.
Reaction of 2-hexanone with 3 results in the formation
of two diastereomers of the dimeric product [CpTi(SCH-
(C(CH3)(C4H9)O)CH2CH2S)]2 (16a ,b), in a ratio of 2:1.
NOE experiments were consistent with a geometry of
the major isomer in which the butyl substituents are
oriented away from the cyclopentadienyl rings. This
relieves steric congestion in a manner similar to that
observed for 13 and 14.
Rea ction s w ith Im in es. Compound 3 reacts with
the imine PhCHdNPh to yield two diastereomers of
CpTi(SCH(CHPhNPh)CH2CH2S) (17) in a ratio of 81:
19 (Scheme 4). Similarly two diastereomers of the
analogous species 18 derived from PhCHdN(C6H4OMe)-
and 3 are observed in a 65:35 ratio. The more abundant
isomer was confirmed crystallographically to have the
SR/RS configuration at the chiral carbon atoms (Figure
9), consistent with the assignment of geometry for the
more abundant isomer of 19 based on coupling constant
and NOE data. Analogous reactions with (C6H4OMe)-
CHdNPh and (C6H4OMe)CHd(C6H4OMe) gave similar
ratios of the diastereomeric products 19 and 20. NMR
data for the reaction of the imine PhCHdNPr showed
formation of a single monomeric product with traces of
a dimeric isomer. Successive recrystallization afforded
F igu r e 8. Isomers of 15.
to those described for 11, with the isopropyl groups
oriented away from the cyclopentadienyl ring on the
proximal Ti center. In both 13 and 14, the preferred
geometry is consistent with the minimization of steric
congestion about the metal center.
The reaction of nopinone with 3 affords two mono-
meric diastereomers CpTi(SCH(C9H15O)(CH2CH2S)
(15a ,b) as the major products and a dimeric product 15c
in varying amounts. NOE experiments for 15c are
consistent with a dimeric formulation in which the gem-
dimethyl groups are oriented away from the cyclopen-
tadienyl ring on the proximal Ti center (Figure 8).
When the reaction is performed at -78 °C, the ratio 15a :
15b is 80:20 with a trace of the dimer 15c, while, at
higher temperatures, the amount of dimeric product is
increased. The dependence of the product distribution
on the temperature at which the reaction was performed

Thiatitanacyclopropane Complexes
Organometallics, Vol. 15, No. 9, 1996 2329
F igu r e 10. ORTEP drawing of 21b, with 30% thermal
ellipsoids shown. Hydrogen atoms are omitted for clarity.
Distances and angles: Ti(1)-S(1) 2.38(1) Å, Ti(1)-S(2)
2.52(2) Å, Ti(1)-S(4) 2.59(1) Å, Ti(1)-N(1) 1.98(3) Å, Ti-
(2)-S(2) 2.49(1) Å, Ti(2)-S(3) 2.41(2) Å, Ti(2)-S(4) 2.52-
(2) Å, Ti(2)-N(2) 1.95(2) Å, S(1)-Ti(1)-S(2) 82.0(4)°, S(2)-
Ti(1)-S(4) 74.2(4)°, S(1)-Ti(1)-N(1) 98(1)°, S(2)-Ti(1)-
N(1) 118.4(9)°, S(2)-Ti(2)-S(4) 75.9(5)°, S(3)-Ti(2)-S(4)
80.3(5)°, S(2)-Ti(2)-N(2) 79(1)°, S(4)-Ti(2)-N(2) 121.3-
(7)°, Ti(1)-S(2)-Ti(2) 106.3(6)°, Ti(1)-S(4)-Ti(2) 103.5(6)°.
F igu r e 12. ORTEP drawing of 23, with 30% thermal
ellipsoids shown. Hydrogen atoms are omitted for clarity.
Distances and angles: Ti-S(1) 2.358(2) Å, Ti-S(2) 2.280-
(2) Å, Ti-N(1) 1.956(4) Å, S(1)-Ti-S(2) 105.75(6)°, S(1)-
Ti-N(1) 113.7(1)°, S(2)-Ti-N(1) 88.3(1)°.
F igu r e 11. NOE observed for 22.
a few crystals of the dimeric species 21b. X-ray data
for 21b confirmed the dimeric formulation (Figure 10)
with the relative configurations at the chiral carbons
being SS/RR.
The relative stereochemistry of chiral carbons of
major isomers of 17-21 appears to be dictated by a
minimization of the steric congestion in the interaction
between imine substituents and Ti fragment. Use of a
chiral substrate, rac-(Naphth)CH(CH3)NdCHPh, re-
sulted in the formation of a 50:50 mixture of two
diastereomers of CpTi(SC(CHPhNCHMe(Napth))CH2-
CH2S) (22a ,b). In contrast to 17-21, NOE data (Figure
11) reveal that the phenyl groups on the imine carbons
in 22 are oriented toward the cyclopentadienyl rings.
This implies that the steric demands of the substituent
on N in 22 cause the inversion of the preferred relative
stereochemistry of the imino and methine carbons.
Rea ction s w ith Nitr iles a n d Heter oa llen es. Re-
action of 3 with benzonitrile, valeronitrile, and methyl
thiocyanate proceed in similar fashions yielding purple-
black products 23-25, formulated as mononuclear
products of the form CpTi(SC)(C(R)NH)CH2CH2S)
(Scheme 4). The NMR data reveal the presence of
amido protons consistent with the enolization of the
methine protons to N. Similar, but much slower, proton
migrations were observed by Buchwald et al. in reac-
tions of acetonitrile with the thioformaldehyde adduct
of zirconocene.5-7 Structural data obtained for the
benzonitrile product 23 confirmed the presence of the
olefinic C-C bond and the amido nitrogen (Figure 12).
The interaction of the olefinic bond with the Ti is
indicated by the Ti-C distances of 2.319(5) and 2.387-
(5) Å. A C to N proton migration is observed in the
F igu r e 13. ORTEP drawing of 26, with 30% thermal
ellipsoids shown. Hydrogen atoms are omitted for clarity.
Distances and angles: Ti-S(1) 2.362(4) Å, Ti-S(2) 2.287-
(4) Å, Ti-N(1) 2.033(7) Å, S(1)-Ti-S(2) 108.1(1)°, S(1)-
Ti-N(1) 110.5(3)°, S(2)-Ti-N(1) 89.5(3)°.
product derived from DCC, CpTi(SCd(C(NHCy)NCy)-
CH2CH2S) (26) (Scheme 4), but in this case, the proton
migrates to the exocyclic nitrogen atom producing an
exocyclic amino group (Figure 13).
The reaction of 3 with phenyl isocyanate and phenyl
isothiocyanate results in the formation of the com-
pounds CpTi(SC(PhNCO)CH2CH2S)TiCp(SCH2CH2CH2S)
(27) and CpTi(SCH(PhNCS)CH2CH2S) (28), respectively
(Scheme 4). The formulation of 27 was confirmed
crystallographically (Figure 14). It is thought that these
reactions proceed in a similar fashion. However, in the
case of the phenyl isocyanate reaction, enolization of the
methine proton to the exocyclic oxygen atom takes place
affording an intermediate analogous to 28. The result-
ing alcohol functionality is subsequently quenched by
a second 1 equiv of 3, affording 27.
Mech a n istic Con sid er a tion s. The formation of
both monomeric and dimeric products from the thiati-
tanacycles 3 and 4 is consistent with kinetically com-
petitive reaction pathways. Monitoring of the reactions
of 3 or 4 with cyclohexanone by NMR spectroscopy
revealed the initial formation of a ketone adduct and
subsequent transformation to the products 11 and 12,

2330 Organometallics, Vol. 15, No. 9, 1996
Huang et al.
Ch a r t 1
responsible for the initial coordination of substrate. The
HOMO of CpTi(SCHCH2CH2S) is predominently the
C-based p-orbital of thiacyclopropane ring, and this
orbital is responsible for subsequent attack of the
coordinated substrate resulting in the new C-C bond.
Intramolecular attack is operative in the formation of
the mononuclear complexes 9, 10, and 17-28, while an
intermolecular attack accounts for the formation of the
dimeric products such as 11-14, 15c, 16, and 21b. The
course of the reaction appears to be a subtle result of
steric and electronic factors. In the case of reactions
involving ketones, the accessibility of the ketonic carbon
appears to be a determining factor as dimeric products
prevail when the substrate is more accessible to attack.
Of course, the preferred course of the reaction may be
altered by the conditions as was observed for 15. The
increased donor ability and steric demands of imines
are thought to encourage proximity of the imine carbon
and the thiatitanacycle in the coordination adduct, thus
favoring intramolecular C-C bond formation.
F igu r e 14. ORTEP drawing of 27, with 30% thermal
ellipsoids shown. Hydrogen atoms are omitted for clarity.
Distances and angles: Ti(1)-S(1) 2.356(3) Å, Ti(1)-S(2)
2.267(3) Å, Ti(1)-N(1) 2.012(7) Å, Ti(2)-S(3) 2.265(3) Å,
Ti(2)-S(4) 2.284(3) Å, Ti(2)-O(1) 1.839(6) Å, S(1)-Ti(1)-
S(2) 106.6(1)°, S(1)-Ti(1)-N(1) 110.8(2)°, S(1)-Ti(1)-N(1)
90.6(2)°, S(3)-Ti(2)-S(4) 99.9(1)°, S(3)-Ti(2)-O(1) 104.9-
(2)°, S(4)-Ti(2)-O(1) 103.6(2)°.
Sch em e 5
Su m m a r y. The present study provides a facile and
convenient route to thiametallacyclopropane derivatives
of monocyclopentadienyltitanium. A wide range of
reactivity with organic unsaturates is demonstrated
herein, affirming that in the absence of steric crowding,
as in Cp2Ti(SCH2), thiatitanacyclopropanes are, indeed,
highly reactive. These results augur well for utility of
thiametallacyclopropanes in the preparation of a variety
of organosulfur derivatives. Furthermore, the observa-
tion of varying degrees of diastereoselectivity in reac-
tions with prochiral and chiral substrates is attributed
to a synergism between the molecular dissymmetry of
these thiatitanacyclopropanes and the steric demands
of the substrate. The development of related enanti-
oselective systems is currently under study.
respectively (Scheme 5). The ketone adducts are formed
rapidly in THF but more slowly in benzene. Kinetic
data reveal that, in benzene, the ketone adduct derived
from 4 is formed in a reaction which is first order in 4
(k ) 7.2 × 10-3 s-1). The conversion to 12 appears to
proceed through a number of intermediates suggesting
a complex mechanism. However, kinetic data for the
reaction in THF are approximately second order in the
ketone adduct suggesting the mechanism is dominated
by a bimolecular process (k ) 1.7 × 10-3 Lmol-1 s-1).
For the reaction of 4 with benzophenone, no ketone
complex was observed. In THF the reaction was too fast
to monitor, although in benzene the reaction is first
order in Ti (k ) 2.4 × 10-4 s-1) suggesting that the rate-
determining step is ketone complexation followed by
rapid intramolecular C-C bond formation.
Ack n ow led gm en t. Support from NATO and the
NSERC of Canada is acknowledged. The award of an
Ontario Graduate Scholarship to T.T.N. as well as
summer support from the Electrochemical Society (U.S.-
DOE) is also gratefully acknowledged. D.W.S. is grate-
ful for DFG/NSERC support of visiting professorship at
Westfalische Wilhelms Universitaet. Professor G. Erker
is thanked for helpful discussions.
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal-
lographic data, positional and thermal parameters, and se-
lected bond distances and angles (44 pages). Ordering infor-
mation is given on any current masthead page.
EHMO calculations done for the fragment CpTi-
(SCHCH2CH2S) show the LUMO is a vacant metal-
based d orbital (Chart 1). This Lewis acidic orbital is
OM960108G