Supporting Information

Revised

Supporting Information

Olefin Polymerization Behavior of Titanium(IV) Pyridine-2-Phenolate-6-(σ-Aryl) Catalysts: Impact of ‘py-Adjacent’ and Phenolate Substituents

Jerry C. Y. Lo,a Michael C. W. Chan,*,a Po-Kam Lo,a Kai-Chung Lau,*,a and Haruyuki Makiob

a

Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon,

Hong Kong, China (email: [email protected], [email protected]). b

Mitsui Chemicals Singapore R&D Centre Pte. Ltd., 50 Science Park Road, #06-08 The Kendall

Singapore Science Park II, Singapore 117406.

1–7

Experimental details and characterization data for H2L additional results for DFT calculations.

S1

; selected NMR data for 1–7; GPC traces;

Revised

Synthetic Procedures The general synthetic route for 2-phenol-6-arylpyridine ligands (including H2L4) was modified from: (a) Silva, A. M. S.; Almeida, L. M. P. M.; Cavaleiro, J. A. S.; Foces-Foces, C.; Llamas-Saiz, A. L.; Fontenas, C.; Jagerovic, N.; Elguero, J. Tetrahedron 1997, 53, 11645, and (b) Dietrich-Buchecker, C.; Sauvage, J. P. Tetrahedron 1990, 46, 503.

Synthesis of Intermediate I-1 O N

A mixture of 1-acetylnaphthalene (3 g, 17.63 mmol) and N,N-dimethylformamide dimethyl acetal (4.7 mL, 35.38 mmol) were refluxed at 120 oC for 18 hours to give a red solution. The product was extracted with dichloromethane, washed by brine and water, and dried over magnesium sulfate. After the solvent was removed by evaporation, the crude product was purified by silica gel flash chromatography using n-hexane:ethyl acetate (10:1) as eluent to give a red oil. Yield: 3.5 g, 88 %. 1H NMR (300 MHz, CDCl3): δ 2.82 (br s, 3H, NCH3), 2.99 (br s, 3H, NCH3), 5.49 (d, J = 12.7 Hz, 1H), 7.41–7.56 (m, 5H), 7.80–7.85 (m, 2H), 8.25 (br, 1H).

Synthesis of Intermediate I-2 F

O N

The procedure for the synthesis of I-1 was adopted, using 2-fluoro-acetophenone (3.0 g, 21.72 mmol). Yield: 3.7 g, 88 %. 1H NMR (300 MHz, CDCl3): δ 2.90 (br s, 3H, NCH3), 3.13 (br s, 3H, NCH3), 5.62 (dd, J = 12.6 Hz, 2.0 Hz, 1H), 7.03–7.09 (m, 1H), 7.17 (td, J = 7.5 Hz, 1.1 Hz, 1H), 7.33–7.41 (m, 1H), 7.72–7.77 (m, 2H).

S2

Revised

Synthesis of Intermediate I-3 (left) and H2L1 (right) F

F N

N OH

OMe

3,5-di-t-butyl-2-methoxyacetophenone (3.50 g, 13.34 mmol) and potassium tert-butoxide (3.00 g, 26.74 mmol) was stirred in THF (40 mL) for 12 hours at room temperature under a nitrogen atmosphere to give a dark brown suspension. A solution of I-2 (2.58 g, 13.34 mmol) in THF (40 mL) was then added and the mixture was stirred for 36 hours at room temperature. A solution of ammonium acetate (10.3 g, 133.6 mmol) in acetic acid (30 mL) was added. After distillation of THF at 130 oC for 2 hours, the resultant mixture was washed by brine and water, extracted with dichloromethane, and dried over magnesium sulfate. The solvent was removed to give a red oil, which was purified by silica gel flash chromatography using n-hexane as eluent to give I-3 as a yellow solid. Yield: 3.22 g, 59 %. 1H NMR (300 MHz, CDCl3): δ 1.36 (s, 9H, tBu), 1.45 (s, 9H, tBu), 3.38 (s, 3H, OMe), 7.14–7.21 (m, 1H), 7.28 (td, J = 7.5 Hz, 1.4 Hz, 1H), 7.35–7.41 (m, 2H), 7.59 (d, J = 2.5 Hz, 1H), 7.73–7.80 (m, 3H), 8.16 (td, J = 7.8 Hz, 1.8 Hz, 1H). Intermediate I-3 (3.0 g, 7.3 mmol) was demethylated in molten pyridinium chloride (8.0 g, 69.2 mmol) under a nitrogen atmosphere at 210 oC for 12 hours. The resultant mixture was extracted with dichloromethane, washed by brine and water, and dried over magnesium sulfate. After evaporation of solvent, the product was purified by silica gel flash chromatography using n-hexane as eluent to give a yellow solid. Yield: 1.55 g, 56 %. 1H NMR (300 MHz, CDCl3): δ 1.37 (s, 9H, tBu), 1.49 (s, 9H, tBu), 7.18–7.25 (m, 1H), 7.34 (td, J = 7.5 Hz, 1.1 Hz, 1H), 7.40–7.48 (m, 2H), 7.64–7.70 (m, 2H), 7.86–7.91 (m, 3H), 14.41 (s, 1H, OH). δ –117.22. ESI-MS (+ve, m/z): 378.6 [M+].

S3

19

F NMR (282 MHz, CDCl3):

Revised

Synthesis of Intermediate I-4

F

O N

F

The procedure for the synthesis of I-1 was adopted, using 2,4-difluoro-acetophenone (2.0 g, 12.81 mmol). Yield: 2.57 g, 95 %. 1H NMR (300 MHz, CDCl3): δ 2.89 (br s, 3H, NCH3), 3.13 (br s, 3H, NCH3), 5.59 (dd, J = 12.4 Hz, 2.2 Hz, 1H), 6.79 (m, 1H), 6.89 (m, 1H), 7.74–7.84 (m, 2H).

Synthesis of Intermediate I-5 (left) and H2L2 (right) F

F

N

N F

OMe

OH

F

The procedure for the synthesis of I-3 was adopted, using I-4 (2.77 g, 13.11 mmol), to give I-5 as a yellow solid. Yield: 2.04 g, 45 %. 1H NMR (300 MHz, CDCl3): δ 1.36 (s, 9H, tBu), 1.45 (s, 9H, tBu), 3.37 (s, 3H, OMe), 6.93 (m, 1H), 6.99–7.06 (m, 1H), 7.41 (d, J = 2.8 Hz, 1H), 7.57 (d, J = 2.8 Hz, 1H), 7.70–7.82 (m, 3H), 8.19 (m, 1H). 19F NMR (282 MHz, CDCl3): δ –110.01, –113.01. The procedure for the synthesis of H2L1 was adopted, using I-5 (2.22 g, 5.42 mmol) to give H2L2 as a yellow solid. Yield: 1.08 g, 50 %. 1H NMR (300 MHz, CDCl3): δ 1.38 (s, 9H, tBu), 1.50 (s, 9H, tBu), 6.98 (m, 1H), 7.05–7.12 (m, 1H), 7.44 (d, J = 2.1 Hz, 1H), 7.60–7.64 (m, 1H), 7.70 (d, J = 2.5 Hz, 1H), 7.85–7.94 (m, 3H), 14.34 (s, 1H, OH).

19

F NMR (282 MHz, CDCl3):

+

δ –108.66, –112.75. ESI-MS (+ve, m/z): 396.1 [M ].


CF3

O N

The procedure for the synthesis of I-1 was adopted, using 2-(trifluoromethyl)acetophenone (6.5 g, 34.5 mmol). Yield: 8.0 g, 95 %. 1H NMR (300 MHz, CDCl3): δ 2.86 (s, 3H, NCH3), 3.08 (br s, 3H, NCH3), 5.25–5.35 (m, 1H), 7.39–7.48 (m, 2H), 7.52–7.57 (m, 1H), 7.67 (d, J = 7.3 Hz, 1H). S4

Revised

Synthesis of Intermediate I-7 (left) and H2L3 (right) CF3

CF3

N

N

OMe

OH

The procedure for the synthesis of I-3 was adopted, using I-6 (8.0 g, 32.9 mmol), to give I-7 as a yellow solid. Yield: 3.9 g, 32 %. 1H NMR (300 MHz, CDCl3): δ 1.34 (s, 9H, tBu), 1.44 (s, 9H, tBu), 3.36 (s, 3H, OMe), 7.36–7.39 (m, 2H), 7.50–7.63 (m, 4H), 7.79–7.81 (m, 3H). The procedure for the synthesis of H2L1 was adopted, using I-7 (3.9 g, 8.9 mmol) except H2L3 was purified by silica gel flash chromatography using n-pentane as eluent. Yield: 0.89 g, 24 %. 1H NMR (300 MHz, CDCl3): δ 1.37 (s, 9H, tBu), 1.44 (s, 9H, tBu), 7.32 (d, J = 7.5 Hz, 1H), 7.40 (d, J = 2.5 Hz, 1H), 7.54–7.61 (m, 2H), 7.66 (d, J = 7.1 Hz, 1H), 7.71 (d, J = 2.5 Hz, 1H), 7.81 (d, J = 7.8 Hz, 1H), 7.88 (t, J = 8.0 Hz, 1H), 7.96 (d, J = 8.2 Hz, 1H), 14.12 (s, 1H, OH). 19F NMR (282 MHz, CDCl3): δ –57.14. ESI-MS (+ve, m/z): 428.3 [M+].


A solution of n-butyllithium (10.0 mL, 1.6 M in hexanes, 16.0 mmol) was slowly added at –78 °C to 1-(ethoxymethoxy)-2-(trifluoromethyl)benzene (3.165 g, 14.37 mmol) in THF (40 mL) to give an orange solution. The mixture was stirred at –78 °C for 1 hour. Ethanal (2.4 mL, 42.9 mmol) was then added, and the resultant mixture was stirred for 12 hours at room temperature. Diethyl ether (30 mL) was added, and a solution of sodium dichromate dihydrate (6.4 g, 21.5 mmol) and concentrated sulfuric acid (6.4 mL) in DI water (20 mL) was slowly added at –50 °C. The black solution was slowly warmed to room temperature and stirred for 1 hour. The organic layer was washed by water and brine, and dried over magnesium sulfate. After the evaporation of solvents, the product was purified by silica gel flash chromatography using n-hexane as eluent to S5

Revised

give a yellow oil. Yield: 3.01 g, 80 %. 1H NMR (300 MHz, CDCl3): 1.20 (t, J = 7.2 Hz, 3H, OCH2CH3), 2.64 (s, 3H, O=CMe), 3.71 (q, J = 7.0 Hz, 2H, OCH2CH3), 5.06 (s, 2H, OCH2O), 7.26–7.31 (m, 1H), 7.70 (dd, J = 7.8 Hz, 1.6 Hz, 1H), 7.74 (dd, J = 7.8 Hz, 1.3 Hz, 1H).

Synthesis of H2L5 N OH CF3

Intermediate I-8 (2.50 g, 9.54 mmol) and potassium tert-butoxide (2.74 g, 24.42 mmol) were stirred in THF (30 mL) for 12 hours at room temperature under a nitrogen atmosphere to give a dark red solution. A solution of I-1 (2.37 g, 10.52 mmol) in THF (25 mL) was added, and the mixture was stirred for 36 hours at room temperature. A solution of ammonium acetate (8.37 g, 108.6 mmol) in acetic acid (30 mL) was slowly added at –50 oC, after which the reaction was warmed to room temperature. THF was removed by distillation at 130 oC for 2 hours, and the resultant mixture was extracted with dichloromethane, washed by water and brine, and dried over magnesium sulfate. Solvents were removed to give a red oil, which was purified by silica gel flash chromatography using n-hexane and ethyl acetate (100:1) as eluent to give a pale yellow solid. Yield: 0.83 g, 30 %. 1H NMR (300 MHz, CDCl3): 7.00 (t, J = 7.8 Hz, 1H), 7.47–7.68 (m, 6H), 7.93–8.10 (m, 6H), 15.61 (s, 1H, OH). 19F NMR (300 MHz, CDCl3): –63.28. ESI-MS (+ve, m/z): 365.8 [M+].

Synthesis of Intermediate I-9 O

O

O

The procedure for the synthesis of I-8 was adopted, using 2-(ethoxymethoxy)-1-iodo-5methyl-3-(2-phenylpropan-2-yl)benzene (2.83 g, 6.90 mmol). Yield: 1.84 g, 82 %. 1H NMR (300 S6

Revised

MHz, CDCl3): 1.02 (t, J = 7.1 Hz, 3H, OCH2CH3), 1.71 (s, 6H, C(Ph)Me2), 2.38 (s, 3H), 2.49 (s, 3H), 3.26 (q, J = 7.0 Hz, 2H, OCH2CH3), 3.55 (s, 2H, OCH2O), 7.12–7.23 (m, 6H), 7.46 (s, 1H).

Synthesis of H2L6 N OH

The procedure for the synthesis of H2L5 was adopted, using I-9 (1.80 g, 5.51 mmol). Yield: 0.47 g, 20 %. 1H NMR (300 MHz, CDCl3): 1.71 (s, 6H, C(Ph)Me2), 2.43 (s, 3H, Ph-Me), 7.06–7.09 (m, 1H), 7.14–7.22 (m, 4H), 7.33–7.38 (m, 2H), 7.43 (dd, J = 6.8 Hz, 1.6 Hz, 1H), 7.45–7.57 (m, 3H), 7.63 (d, J = 1.5 Hz, 1H), 7.87–7.98 (m, 5H), 13.87 (s, 1H, OH).


O

O

Methylmagnesium

chloride

(1.2

mL,

O

3.6

mmol)

was

slowly

added

to

3-(1,1-diphenylethyl)-2-(ethoxymethoxy)benzaldehyde (1.11 g, 3.08 mmol) at 0 oC in THF (20 mL) under a nitrogen atmosphere. The brown solution was stirred at room temperature for 12 hours. After addition of diethyl ether (100 mL), a solution of concentrated sulfuric acid (2 mL) and sodium dichromate dehydrate (1.8 g, 6.0 mmol) in water was slowly added at –50 oC. The resultant black mixture was allowed to stir at room temperature for 1 hour, and the organic layer was then washed by brine and water, and dried over magnesium sulfate. The product was purified by silica gel flash chromatography using n-hexane:ethyl acetate (100:1) as eluent. Yield: 0.84 g, 73 %. 1H NMR (300 MHz, CDCl3): 1.04 (t, J = 7.2 Hz, 3H, OCH2CH3), 2.38 (s, 3H), 2.57 (s, 3H), 3.28 (q, J S7

Revised

= 7.1 Hz, OCH2CH3), 3.94 (s, 2H, OCH2O), 6.91 (dd, J = 7.9 Hz, 1.8 Hz, 1H), 6.98 (t, J = 7.6 Hz, 1H), 7.07–7.11 (m, 4H), 7.19–7.35 (m, 7H).

Synthesis of H2L7 N OH

The procedure for the synthesis of H2L5 was adopted, using I-10 (0.84 g, 2.24 mmol). Yield: 0.26 g, 24 %. 1H NMR (300 MHz, CDCl3): 2.35 (s, 3H, Me), 6.63 (dd, J = 7.9 Hz, 1.7 Hz, 1H), 6.77 (t, J = 7.9 Hz, 1H), 7.12–7.18 (m, 6H), 7.21–7.23 (m, 4H), 7.36–7.42 (m, 1H), 7.46–7.51 (m, 2H), 7.54 (d, J = 7.7 Hz, 1H), 7.58 (dd, J = 7.3 Hz, 1.5 Hz, 1H), 7.84 (dd, J = 8.1 Hz, 1.8 Hz, 1H), 7.88–7.93 (m, 2H), 7.94–8.00 (m, 3H), 14.48 (s, 1H, OH). ESI-MS (+ve, m/z): 478.2 [M+].

S8

Revised

Table S1. Selected NMR parameters for benzyl group a

complex

CH2 (ppm)

1

3.95, 4.14

2

a

2

JH,H (Hz)

1

JC,H (Hz)

o-Ph (ppm)

m-Ph (ppm)

p-Ph (ppm)

8.2

135.0b

6.73 (d)

6.57 (t)

6.41 (t)

3.88, 3.98

8.5

135.6

6.69 (d)

6.56 (t)

6.41 (t)

3

3.94, 4.08

8.4

135.8

6.62 (d)

6.52 (t)

6.38 (t)

4

3.98, 4.22

8.5

134.8

6.71–6.74 (m)

6.46 (t)

6.35 (t)

5

4.05, 4.15

8.2

137.4

6.76 (d)

6.45 (t)

6.33 (t)

6

3.42, 4.09

8.0

135.3

6.34 (d)c

6.41 (t)

6.30 (t)

7

3.36, 4.01

8.0

135.3

6.41–6.49 (m)c

6.41–6.49 (m)

6.36 (m)

In C6D6 (1H: 400 MHz; 13C: 101 MHz; 298 K) unless otherwise stated.

b

In CD2Cl2.

c

Upfield

shifts are attributed to ring currents from cumyl or CPh2Me phenolate substituent.

R5

R5

R1

R1

2

R

N R4

O

N R4

R3

M

'syn, anti'

O

M

R2 R3

'anti, anti'

Figure S1. ‘Syn, anti’ and ‘anti, anti’ conformations of bis(benzyl) groups in X-ray crystal structures of [O,N,C] complexes.

S9

dwt/d(logM)

dwt/d(logM)

Revised

3

5

7

9

ｌogM

3

5

7 logM

50℃

100℃

Figure S2. GPC traces of PE samples produced by 6 (left) and 7 (right) at different temperatures.

Reference for Gaussian 09 program package: Gaussian 09, revision B.1, Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Mennucci, B.; Petersson, G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H. P.; Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, Jr., J. A.; Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin, K. N.; Staroverov, V. N.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Rega, N.; Millam, N. J.; Klene, M.; Knox, J. E.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Zakrzewski, V. G.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, Ö.; Foresman, J. B.; Ortiz, J. V.; Cioslowski, J.; Fox, D. J. Gaussian, Inc., Wallingford CT, USA, 2009.

S10

9

Revised

Table S2. Relative energies (∆G298°, kcal/mol) of all structures in C2H4 insertion pathways mediated by 1+−4+ in toluene at the B97D level using LanL2DZ (Ti) and 6-311G(d,p) (non-metals) basis sets. complex

complex +2C2H4

INT1a +C2H4

TS1a +C2H4

INT2a +C2H4

TS2a

INT3a

TS2b +C2H4

INT3b +C2H4

1+

0.0

−0.4

8.7

−11.7

13.2

−10.4

13.6

2.4

2+

0.0

−0.4

9.8

−11.5

14.5

−9.0

13.4

2.1

3+

0.0

−0.2

7.8

−13.6

10.7

−13.1

13.6

4.0

4+

0.0

−0.4

7.8

−14.3

10.6

−13.2

14.9

4.7

S11

Revised

Scheme S1. Gibbs free energy surface for C2H4 insertions into Ti−C(σ-aryl) [first insertion: pathway a, i.e. C2H4 assimilation] and Ti−C(alkyl) [first insertion: pathway b] bonds of 4′+ methyl cation (conformers I and II) at the B97D level using LanL2DZ (Ti) and 6-311G(d,p) (non-metals) basis sets. Relative energies at 298 K in toluene (kcal/mol) and selected interatomic distances (Å) are given.

S12

Revised

I

II

III

IV

Figure S3. Calculated structures of conformers I−IV for TS2a of 4+.

S13

Revised

Figure S4. Energy-minimized calculated structure for the 7+ species, showing Ti···π(Ph) coordination (in Å) by the CPh2Me phenolate substituent.

S14