Selective hydrosilylation of allyl chloride with trichlorosilane

The transition-metal-catalysed hydrosilylation reaction of alkenes is one of the most important catalytic reactions in the silicon industry. In this field, intensive studies have been thus far performed in the development of base-metal catalysts due to increased emphasis on environmental sustainability. However, one big drawback remains to be overcome in this field: the limited functional group compatibility of the currently available Pt hydrosilylation catalysts in the silicon industry. This is a serious issue in the production of trichloro(3-chloropropyl)silane, which is industrially synthesized on the order of several thousand tons per year as a key intermediate to access various silane coupling agents. In the present study, an efficient hydrosilylation reaction of allyl chloride with trichlorosilane is achieved using the Rh(I) catalyst [RhCl(dppbzF)]2 (dppbzF = 1,2-bis(diphenylphosphino)-3,4,5,6-tetrafluorobenzene) to selectively form trichloro(3-chloropropyl)silane. The catalyst enables drastically improved efficiency (turnover number, TON, 140,000) and selectivity (>99%) to be achieved compared to conventional Pt catalysts.


Experimental details and compound characterization data
General procedures for catalytic hydrosilylation of allyl chloride (Table 1, Table 2
Detailed reaction conditions for each experiment were listed in Supplementary Tables 1-3.
Identification of 5 7 , 6 8 , and 7 14 was performed by comparing the authentic samples that were alternatively synthesised by the literature procedures of the structurally similar complexes.
To the solution, was added a THF (3 mL) solution containing dppbz (45 mg, 0.94 mmol) slowly over 5 min at -78 °C, and the mixture was stirred at the same temperature for 30 min. The solution was warmed to room temperature and concentrated to dryness in vacuo. The resulting residue was extracted with benzene (10 mL × 3) and hexane (10 mL × 3) and concentrated to dryness under vacuum to give 5 as an orange solid (41 mg, 0.035 mmol, 86%).
To the solution, was added a benzene (3 mL) solution containing dppbz (36 mg, 0.080 mmol). After stirring at room temperature for 30 min, the solution was concentrated to dryness in vacuo at room temperature, and the resulting residue was washed with benzene (10 mL × 3). After drying, the resulting residue was dissolved in CH2Cl2/hexane (2 mL/0.5 mL) and stored at -30 °C to give 7 as an orange solid (79%, 33 mg, 0.032 mmol).
To the solution, was added a benzene (3 mL) solution containing dppbz OMe (47 mg, 0.093 mmol) slowly over 5 min at -30 °C. After stirring at room temperature for 30 min, the solution was concentrated to dryness in vacuo at room temperature, and the resulting residue was extract with benzene (10 mL × 3). After benzene was removed by evaporation, the obtained solid was washed with hexane (10 mL × 3) to give 10 as an orange solid (80%, 42 mg, 0.033 mmol).
After evaporation, the obtained solid was washed with hexane (10 mL × 3) to give 11 as an orange solid (72%, 26 mg, 0.020 mmol).  (Fig. 3a) A THF (2 mL) solution of 11 (50 mg, 0.045 mmol) was placed in a Schlenk tube (20 mL). Allyl chloride (69 mg, 0.90 mmol) was added to the solution, and the mixture was stirred at room temperature for 2 h, resulting in the formation of yellow precipitates. After filtration, the obtained solid was washed with hexane Therefore, identification of the resulting hydride species were not successfull. The observed hydride signals at -15.01 and -16.85 ppm also appeared on the 1 H NMR monitoring of the reaction of [Rh(-Cl)(dppbz F )]2 (11) with HSiCl3 (20 equiv), which resulted in the formation of a complex mixture of unidentified complexes. The identification of these resulting complexes was not successful since these complexes were easily transferred to [Rh(-Cl)(dppbz F )]2 (11) and unidentified complexes after evaporation, probably via reductive elimination. S14 Reaction of [Rh(-allyl)Cl2(dpppbz F )] (12) with cinnamyl chloride (Fig. 3d) A J-young NMR tube was charged with a CD2Cl2 (0.