Tris phenylethyne

Double couplings have been reported by Cummins [143] [bis(tributylstannyl)ethyne with aryl iodides], Tamao et al. [144] [tris(butylstannyl)phenylethyne with a dibromosilacyclo-pentadiene] and Diederich and co-workers [145] [tiis(butylstannyl)phenylethyne with an E-dibromoalkene]. Li et al. have obtained a bis(binaphthol) from a monoiodobinaphthol and bis(tributylstannyl)ethyne [146] in a yield of 66% (Scheme 4-42). 

To a solution of 3.71 g l-(6-0-acetyl-2,3,4-tri-0-benzyl-o -D-mannopyranosyl)-2-6>-(p-toluenesulfoamidyl)phenylethyne (4.99 mmol) in 60 mL EtsN and 30 mL DMF was added 187 mg Cul (0.98 mmol). After stirring at 80°C for 30 min, water was added. The mixture was extracted three times with EtOAc. The combined organic layer was subsequently washed with aqueous NH4CI solution, water, and brine each for two times. Upon removal of the solvent, the residue was purified by silica gel column chromatography using ether/hexanes (1 2) to give 3.28 g 2-(6-0-acetyl-2,3,4-tri-0-benzyl-o -D-mannopyranosyl)-l-(p-toluenesulfonyl) indole, in a yield of 88%. 

Finally some homoleptic alkyne complexes of scandium and some rare earths are known. Tris(phenylethynyl) scandium is formed as a dark brown product after treatment of phenylethyne with butyl lithium at — 78°C in hexane, followed by the addition of scandium trichloride at room temperature. The compound is inflammable in air (Hart and Saran, 1968 Hart et al., 1970). The reaction of the anionic... 

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