Propylamine → (Z)-1-(tert-butyldimethylsilyl)-6-trimethylsilyl-3-hexen-1,5-diyne

Participants

Reaction Conditions

Reaction Steps

Tetrakistriphenylphosphine (4.75 g, 4.10 mmol, 0.48 equiv) was added to a solution of (Z)-1-chloro-4-(tert-butyldimethylsilyl)-1-buten-3-yne (17.2 g, 85.7 mmol, 1 equiv) in ether (160 mL) at -78° C. The resulting suspension was deoxygenated by alternately evacuating the reaction vessel and flushing with argon (5×), then was warmed to 23° C. In another flask, copper iodide (2.45 g, 12.8 mmol, 0.15 equiv) was added to a solution of trimethylsilylacetylene (17.0 mL, 120 mmol, 1.40 equiv) and n-propyl amine (27.5 mL, 334 mmol, 3.90 equiv) in ether (100 mL) at -78° C. The solution was deoxygenated (as above, 5×), then was stirred in an ice bath for 10 min causing the light green solution to turn reddish brown. The reddish brown solution was cooled to -78° C. and the palladium-containing suspension prepared above was added over 5 min via a wide-bore cannula. The mixture was deoxygenated (as above, 5×), then was stirred in an ice bath for 3 h and at 23° C. for 1 h. The reaction mixture was partitioned between saturated aqueous ammonium chloride solution (200 mL) and hexanes (300 mL). The aqueous layer was separated and extracted further with hexanes (2×300 mL). The combined organic layers were dried over sodium sulfate and were concentrated. The residue was filtered, then was purified by distillation under reduced pressure (bp 70°-80° C., 0.5 mmHg) to provide (Z)-1-(tert-butyl-dimethylsilyl)-6-trimethylsilyl-3-hexen-1,5-diyne as a light brown oil (20.4 g, 90%). ##STR29##

Provenance & Evidence