Supporting Information. Sequence-Regulated Copolymers via Tandem Catalysis of Living Radical Polymerization and In Situ Transesterification

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1 Supporting Information Sequence-Regulated Copolymers via Tandem Catalysis of Living Radical Polymerization and In Situ Transesterification Kazuhiro Nakatani, Yusuke Ogura, Yuta Koda, Takaya Terashima*, and Mitsuo Sawamoto* Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Kyotodaigaku-Katsura, Nishikyo-ku, Kyoto , Japan Contents: Experiments S2 Supporting Data Figure S1. Metal alkoxide-catalyzed transesterification of MA and PMA with EtOH S5 Figure S2. Effects of Lewis acid in transesterification of MMA with EtOH S5 Figure S3. Metal alkoxide-catalyzed transesterification of MMA with EtOH S6 Figure S4. MALDI-TOF-MS spectrum of a MMA/EMA gradient copolymer S7 Figure S5. Effects of Al(Oi-Pr) 3 and EtOH on MMA/EMA gradient copolymers S8 Figure S6. SEC curves of RMA/EMA gradient copolymers obtained with Ti(Oi-Pr) 4 S9 Figure S7. DSC thermograms of gradient copolymers S10 S1

2 Experimental Section Materials Methyl methacrylate (MMA: Tokyo Kasei; purity > 99.8%), methyl acrylate (MA: Tokyo Kasei; purity > 99%), dodecyl methacrylate (DMA: Tokyo Kasei; purity > 95%), isopropyl methacrylate (i-prma: Tokyo Kasei; purity > 98%), tert-butyl methacrylate (t-buma: Tokyo Kasei; purity > 98%) and tetralin (1,2,3,4-tetrahydronaphthalene) (Kishida Chemical, purity > 98%, internal standard for 1 H NMR analysis) were dried overnight over calcium chloride and distilled twice from calcium hydride under reduced pressure before use. Ethyl 2-chloro-2-phenylacetate (ECPA: Aldrich; purity > 97%) was distilled under reduced pressure before use. Ru(Ind)Cl(PPh 3 ) 2 (Aldrich), Al(Oi-Pr) 3 (Aldrich, purity > 99%), Al 2 O 3 (Aldrich, purity > 99.99%), Fe 2 O 3 (Aldrich, purity > 99.98%) and Sb 2 O 3 (Aldrich, purity > %) were used as received and handled in a glove box under moisture- and oxygen-free argon (H 2 O < 1 ppm; O 2 < 1 ppm). Ti(Oi-Pr) 4 (Kanto Chemicals, purity > 97%), TiCl 4 (Aldrich, 1.0 M in toluene), SnCl 4 (Aldrich, 1.0 M in toluene), BF 3 OEt 2 (Aldrich) and ZnCl 2 (Aldrich, 1.0 M in Et 2 O) were used as received. Ethanol (EtOH: Wako; dehydrated), benzyl alcohol (BzOH: Wako; purity > 99%), 1-dodecanol (Wako, purity > 95%), poly(ethylene glycol) methyl ether (PEG-OH: Aldrich; M n = 550), and n-bu 3 N (Tokyo Kasei, purity > 99%) were degassed before use. Toluene (solvent) was purified before use by passing it through a purification column (Glass Contour Solvent Systems: SG Water USA). Transesterification The reaction was carried out by the syringe technique under dry argon in baked glass tubes equipped with a three-way stopcock. A typical procedure for Al(Oi-Pr) 3 -catalyzed transesterification of MMA in toluene/etoh (1/1, v/v) is given. Into a glass tube, toluene (0.70 ml), a toluene solution of Al(Oi-Pr) 3 (125 mm, 0.48 ml, Al(Oi-Pr) 3 = 0.06 mmol), MMA (0.64 ml, 6 mmol), and EtOH (1.18 ml) were added at room temperature under dry argon. The total volume of the reaction mixture was thus 3.0 ml. The glass tube was immediately placed in an oil bath kept at 80 C. At predetermined intervals, a small portion of the mixture was sampled with a syringe under dry argon, and the reaction was terminated by cooling the solution to 78 C. The conversion was determined by 1 H NMR in CDCl 3. S2

3 Gradient Copolymers via Tandem Catalysis The polymerization was carried out by the syringe technique under argon in baked glass tubes equipped with a three-way stopcock. A typical procedure for tandem catalysis of MMA with ECPA/Ru(Ind)Cl(PPh 3 ) 2 /Al(Oi-Pr) 3 in toluene/etoh (1/1, v/v) is given. Ru(Ind)Cl(PPh 3 ) 2 (4.46 mg, mmol) was placed into a glass tube. Toluene (0.56 ml), tetralin (0.08 ml), a 125 mm toluene solution of Al(Oi-Pr) 3 (0.48 ml, 0.06 mmol), MMA (0.64 ml, 6 mmol), EtOH (1.14 ml), and a 610 mm toluene solution of ECPA (0.1 ml, 0.06 mmol) were sequentially added in that order into the tube at room temperature under argon. The total volume of the reaction mixture was thus 3.0 ml. The glass tube was immediately placed in an oil bath kept at 80 C. At predetermined intervals, the mixture was sampled with a syringe under argon, and the reaction was terminated by cooling the solution to 78 C. The monomer conversion and composition in a polymerization solution, and the repeat-unit composition of polymers were determined by 1 H NMR in CDCl 3 with tetralin as an internal standard. The quenched reaction solutions were washed with water and evaporated to dryness. The products were subsequently dried overnight under vacuum at room temperature. SEC (CHCl 3, PMMA std.): M n = 11,300; M w /M n = H NMR (500 MHz, CDCl 3 ): δ (5H, aromatic), 4.2 (2H, -CH(Ph)CO 2 CH 2 CH 3 ), (105H, -C(CH 3 )(CO 2 CH 2 CH 3 )-), (209H, -CO 2 CH 3 ), 3.35 (1H, -COCH(Ph)-), (244H, -CH 2 -), (527H, - CCH 3 ). Cumulative contents (F cum ) of EMA and MMA: F cum,mma /F cum,ema = 57/43. Gradient Block Copolymers via Tandem Catalysis The polymerization was carried out by the syringe technique under argon in baked glass tubes equipped with a three-way stopcock. The procedure to prepare the gradient triblock copolymer, [PMMA-grad-Pi-PrMA]-b-[PMMA-grad-PEMA]-b-[PMMA-grad-PBzMA], is given. Ru(Ind)Cl(PPh 3 ) 2 (13.97 mg, mmol) was placed in an glass tube. Toluene (2.81 ml), tetralin (0.24 ml), a 500 mm toluene solution of Ti(Oi-Pr) 4 (0.36 ml, 0.18 mmol), MMA (1.92 ml, 18 mmol), i-proh (3.42 ml) and a 707 mm toluene solution of ECPA (0.25 ml, 0.18 mmol) were added sequentially in that order into the tube at room temperature. The total volume of the reaction mixture was thus 9.0 ml. Immediately after mixing, the mixture was placed in an oil bath kept at 80 C until the conversion reached around 50% (1st segment). 6.0 ml of the polymerization solution was transferred to the other baked glass tube at room temperature and the S3

4 solution was evaporated under vacuum to remove the residual monomers and solvents. After filled with argon, the glass tube was charged with toluene (2.36 ml), MMA (1.28 ml, 12 mmol) and EtOH (2.36 ml). The mixture was placed in an oil bath kept at 80 C until the conversion reached around 50% (2nd segment). A similar procedure with MMA and BzOH was conducted for the 3rd segment. At predetermined intervals, the mixture was sampled with a syringe under argon, and the reaction was terminated by cooling the solution to 78 C. The monomer conversion and composition in a polymerization solution, and the repeat-unit composition of polymers were determined by 1 H NMR in CDCl 3 with tetralin as an internal standard. The quenched reaction solutions were washed with water and evaporated to dryness. The resulting products were subsequently dried overnight under vacuum. SEC (CHCl 3, PMMA std.): M n = 24,600 g/mol; M w /M n = Cumulative contents (F cum ) of monomer units: (F cum,mma / F cum,iprma ) 1st /(F cum,mma /F cum,ema ) 2nd /(F cum,mma /F cum,bzma ) 3rd = (66/34) 1st /(31/69) 2nd /(85/15) 3rd. Measurements The molecular weight distribution (MWD) curves, M n, and M w /M n ratio of the polymers were measured by size-exclusion chromatography (SEC) in chloroform at 40 C using three linear-type polystyrene gel columns [Shodex K-805L: particle size = 10 µm; pore size = 5000 Å; 0.8 cm i.d. 30 cm; exclusion limit = g/mol; flow rate = 1.0 ml/min] that were connected to a Jasco PU-980 precision pump, a Jasco RI-930 refractive index detector, and a Jasco UV/vis detector set at 250 nm. The columns were calibrated against 10 standard poly(mma) samples (Polymer Laboratories; M n = ; M w /M n = ). 1 H NMR spectra were recorded in CDCl 3 at room temperature on a JEOL JNM-LA500 spectrometer operating at MHz. MALDI-TOF-MS analysis was performed on a Shimadzu AXIMA-CFR instrument equipped with 1.2 m linear flight tubes and a 337 nm nitrogen laser, with dithranol (1, 8, 9-anthracenetriol) as an ionizing matrix and sodium trifluoroacetate as a cationizing agent. Differential scanning calorimetry (DSC) was performed for polymer samples (ca. 4 mg weighed into an aluminum pan) under a dry nitrogen flow on a DSCQ200 calorimeter (TA Instruments) equipped with a RCS 90 electric freezing machine. The heating and cooling rates were performed at 20 o C/min and -20 o C/min, respectively, between -80 o C and 150 o C. Polymer samples for DSC and MALDI-TOF-MS analyses were fractionated by preparative SEC [column: Shodex K-5002; particle size = 15 µm; 5.0 cm i.d. 30 cm; exclusion limit = g/mol; flow rate = 10 ml/min]. S4

5 Supporting Data Figure S1. Metal alkoxide-catalyzed transesterification of MA or PMA (M n = 8000) in toluene/ethanol (EtOH) (1/1, v/v) at 80 C: [MA] 0 or [PMA] 0 = 20 mm; [Al(Oi-Pr) 3 ] 0 or [Ti(Oi-Pr) 4 ] 0 = 20 mm. Figure S2. Effects of Lewis acid in transesterification of MMA with EtOH: [MMA] 0 = 2.0 M; [Lewis acid] 0 = 100 mm in toluene/etoh (1/1, v/v) at 80 C. S5

6 Figure S3. Metal alkoxide-catalyzed transesterification of MMA with EtOH. (A) Effects of catalysts [Al(Oi-Pr) 3, Ti(Oi-Pr) 4 ]: [MMA]/[metal alkoxide] = 2000/20 mm in toluene/etoh (1/1, v/v) at 80 C. (B) Effects of temperature: [MMA]/[Al(Oi-Pr) 3 ] = 2000/20 mm in toluene/etoh (1/1, v/v) at 40, 60, and 80 C. (C) Effects of Al(Oi-Pr) 3 : [MMA]/[Al(Oi-Pr) 3 ] = 2000/10, 20, and 40 mm in toluene/etoh (1/1, v/v) at 80 C. (D) Effects of EtOH: [MMA]/[Al(Oi-Pr) 3 ] = 2000/20 mm in toluene/etoh ([EtOH] 0 = 1.0, 4.0, and 6.7 M) at 80 C. S6

7 Figure S4. MALDI-TOF-MS spectrum of a MMA/EMA gradient copolymer (M n = 4600) obtained from the tandem catalysis of ruthenium-catalyzed living radical polymerization and in situ Al(Oi-Pr) 3 -catalyzed transesterification of MMA with EtOH: [MMA]/[ECPA]/[Ru(Ind)Cl(PPh 3 ) 2 ] [Al(Oi-Pr) 3 ] = 2000/20/2.0/20 mm in toluene/etoh (1/1, v/v) at 80 C. S7

8 Figure S5. Effects of Al(Oi-Pr) 3 and EtOH concentration on MMA/EMA gradient copolymers obtained from the tandem catalysis of ruthenium-catalyzed living radical polymerization and in situ Al(Oi-Pr) 3 -catalyzed transesterification: (A, B) total monomer conversion and EMA contents in monomer as a function of polymerization time; (C) SEC curves of products (dash lines: products in % conversion); [MMA]/[ECPA]/[Ru(Ind)Cl(PPh 3 ) 2 ]/[Al(Oi-Pr) 3 ] = 2000/20/2.0/40, 20, 15, and 10 mm in toluene and EtOH ([EtOH] = 2.0, 4.0, 6.5 M) at 80 C. S8

9 Figure S6. SEC curves of products obtained from the tandem catalysis of ruthenium-catalyzed living radical polymerization and in situ Ti(Oi-Pr) 4 -catalyzed transesterification of monomers (RMA: MMA; DMA; i-prma; t-buma): [RMA] 0 /[ECPA] 0 /[Ru(Ind)Cl(PPh 3 ) 2 ] 0 /[Ti(Oi-Pr) 4 ] 0 = 2000/20/2.0/20 mm in toluene/etoh (1/1, v/v) at 80 C. S9

10 Figure S7. DSC thermograms recorded on gradient copolymers of (A) MMA/EMA (57/43), (B) MMA/EMA (25/75), (C) MMA/BzMA (55/45), (D) MMA/DodecylMA (56/44), and (E) MMA/PEGMA (69/31) during the second heat scanning from -80 o C to 150 o C (heating rate: 20 o C/min). The samples (A-E) correspond to entry 3-7 in Table 2 in the main text, respectively. S10