Buta-1,2,3-trienylidene, acylvinylidene and acylalkynyl ruthenium complexes via activation of alkynes with RuCl2(dppe)2.: X-ray structure of trans-[Ru(=C=CHCOCH2Ph)(Cl)(dppe)2]O3SCF3

The activation of several functional alkynes HC=C-C=C-Ph (a), HC=CCOCHPh2 (b) and HC=C-CHOH-CHPh2 (c) with the precursor [RuCl(dppe)(2)]PF6[RuCl(dppe)(2) = {Ru}], in situ generated from RuCl2(dppe)(2)NaPF6, has been performed. It selectively produces the buta-1,2,3-trienylidene {Ru}=C=C=C=CHR]+PF6- intermediates (I) from a, and acylvinylidene complexes (Ru)=C=CH-COR]+PF6- [R = CH2Ph (3) and R = CHPh2 (5)] from a and b and {Ru}=C=CH-CH=CPh2]+PF6- (10) from c. The deprotonation of 3, 5 and 10, respectively, affords acylalkynyl derivatives {Ru}-C=C-CO-R] 4, 6 and {Ru}-C=C-CH=CPh2] 11. The X-ray diffraction study of trans-[(Cl)(dppe)(2)Ru=C=CHCOCH2Ph]O3SCF3 3, obtained by reaction of {Ru}-C=C-C=CPh] with CF3SO3H and water, has been carried out. Crystal data are: a 13.362(4), b 23.669(4), c 42.218(6) Angstrom, orthorhombic space group Pbca, Z=8. The structure shows Ru-C(1) (1.77(1) Angstrom) and C(1)-C(2) (1.36(2) Angstrom) bond distances. (C) 1998 Elsevier Science S.A. All rights reserved.