Phenylsilane → 1-Methyltetraline

Participants

Reaction Conditions

Reaction Steps

In a dry sealable Schlenk flask under an argon atmosphere 0.059g (0.099 mmol) (S,S)-ethylene-1.2-bisη5 -4,5,6,7-tetrahydro-1-indenyl)titanium (S)-1,1'-binaphth-2,2'-diolate was dissolved in THF (10 mL). The vessel was degassed by exposure to vacuum (2'~10 sec), put under an atmosphere of hydrogen and subsequently cooled to 0° C. in an ice water bath. After equilibration, a solution of n-butyllithium (0.125 mL, 1.58 M in hexanes, 0.196 mmol, 1.96 equiv) was added and the mixture was allowed to stir for 10 min. Phenylsilane (0.033 mL, 0.259 mmol, 2.6 equiv) and 0.273 g (1.87 mmol, 19 equiv) 1-methyl-3,4-dihydronaphthalene were then added. The flask was sealed and the solution moved into a dry box and transferred to a Parr® high pressure reaction vessel containing a magnetic stir bar. The pressure vessel was sealed and moved to a fume hood where it was charged to 2150 psig with hydrogen and placed in an oil bath at 65° C. The reaction mixture was allowed to stir/br 184 h. The vessel was cooled to room temperature, vented and opened to air. The reaction mixture was worked up by partitioning between diethyl ether/hexane (1/4) and water and separating the layers. The organic extract was distilled at reduced pressure to yield 0.195 g (1.31 mmol, 70%) of 1-methyl-1,2,3,4-tetrahydronaphthalene with an ee of 70 %, determined polarimetrically.

Provenance & Evidence