1,4-Bis(trimethylsilyl)buta-1,3-diyne (CAS NO.: ), which is known as bis(trimethylsilyl)butadiyne, could be produced through the following synthetic route.

A. (I) chloride–tetramethylethylenediamine complex. A 200-mL, three-necked, round-bottomed flask equipped with magnetic stirring bar, rubber septum, nitrogen inlet tube, and bubbler is charged with acetone (90 mL) and copper(I) chloride (5 g, 51 mmol). After the flask is purged with nitrogen, the mixture is stirred and N,N,N',N'-tetramethylethylenediamine (TMEDA) (2.5 mL, 16.6 mmol) is added. Stirring is maintained for 30 min, and the solid material is then allowed to settle, leaving a clear deep-blue-green solution of the CuCl–TMEDA catalyst that is used in the oxidative coupling reaction.

B. 1,4-Bis(trimethylsilyl)buta-1,3-diyne (BTMSBD) (CAS NO.: ). A 1-L, four-necked flask, equipped with a mechanical stirrer, a dry-ice cold-finger condenser, sintered gas inlet, and a swan-neck adapter that supports a thermometer and a rubber septum is charged with acetone (300 mL) and trimethylsilylacetylene (50 g, 0.51 mmol). The reaction mixture is agitated and a rapid stream of oxygen is passed through the solution. The supernatant solution containing the CuCl–TMEDA catalyst is transferred by syringe in 5-mL portions into the reaction vessel. The temperature rises as the catalyst is added and should have reached 35°C after about 75% of the catalyst has been added. When this temperature is reached, external ice cooling is applied to moderate the exothermic reaction. The remaining catalyst is added and the temperature is maintained in the range of 25–30°C for 2.5 hr. When the reaction is complete, there should be no evidence of trimethylsilylacetylene condensing on the cold trap. Agitation and oxygenation are then stopped.

The acetone is removed by evaporation with a rotary evaporator, and the residue is dissolved in petroleum ether (bp 30–40°C, 150 mL) and shaken in a separatory funnel with 3 M aqueous hydrochloric acid (150 mL). The phases are separated and the aqueous phase is washed with petroleum ether (bp 30–40°C, 3 × 150 mL). The combined organic layers are washed with saturated aqueous sodium chloride (50 mL), dried (Na₂SO₄), and evaporated to dryness with a rotary evaporator. The solid residue is dissolved in hot methanol (400 mL) to which has been added 3 M aqueous hydrochloric acid (4 mL). The solution may be filtered at this stage if it is necessary to remove colored insoluble impurities. is then added dropwise until recrystallized material is permanently present. The solution is allowed to cool, finally in ice, and crystalline bis(trimethylsilyl)butadiyne (BTMSBD) is collected. The material is washed with a small portion of ice-cold methanol–water (50 : 50 v/v; 50 mL), and air-dried to give bis(trimethylsilyl)butadiyne (31–35 g, 68–76%), mp 111–112°C (lit. 107–108°C). A further 3–5 g (6–10%) of the product is obtained from the mother liquors.