557790-38-2

Upstream product

• 557790-37-1 Fe(κ²-dppe)(η⁵-C₅Me₅){C≡C(1,4-C₆H₄)C≡CSiMe₃} 
• 557790-36-0 Fe(κ²-dppe)(η⁵-C₅Me₅){C≡C(1,4-C₆H₄)C≡CSi(ⁱPr)₃} 
• 557790-39-3 [(η2-1,2-bis(diphenylphosphino)ethane)(η5-C5Me5)FeCC(1,4-(C6H4)-SiMe3)] 

Relevant academic research and scientific papers

Further Evidence for ‘Extended’ Cumulene Complexes: Derivatives from Reactions with Halide Anions and Water

Reactions of [Ru{C=C(H)-1,4-C6H4C≡CH}(PPh3)2Cp]BF4 ([1 a]BF4) with hydrohalic acids, HX, results in the formation of [Ru{C≡C-1,4-C6H4-C(X)=CH2}(PPh3)2Cp] [X=Cl (2 a-Cl), Br (2 a-Br)], arising from facile Markovnikov addition of halide anions to the putative quinoidal cumulene cation [Ru(=C=C=C6H4=C=CH2)(PPh3)2Cp]+. Similarly, [M{C=C(H)-1,4-C6H4-C≡CH}(LL)Cp]BF4 [M(LL)Cp’=Ru(PPh3)2Cp ([1 a]BF4); Ru(dppe)Cp* ([1 b]BF4); Fe(dppe)Cp ([1 c]BF4); Fe(dppe)Cp* ([1 d]BF4)] react with H+/H2O to give the acyl-functionalised phenylacetylide complexes [M{C≡C-1,4-C6H4-C(=O)CH3}(LL)Cp’] (3 a–d) after workup. The Markovnikov addition of the nucleophile to the remote alkyne in the cations [1 a–d]+ is difficult to rationalise from the vinylidene form of the precursor and is much more satisfactorily explained from initial isomerisation to the quinoidal cumulene complexes [M(=C=C=C6H4=C=CH2)(LL)Cp’]+ prior to attack at the more exposed, remote quaternary carbon. Thus, whilst representative acetylide complexes [Ru(C≡C-1,4-C6H4-C≡CH)(PPh3)2Cp] (4 a) and [Ru(C≡C-1,4-C6H4-C≡CH)(dppe)Cp*] (4 b) reacted with the relatively small electrophiles [CN]+ and [C7H7]+ at the β-carbon to give the expected vinylidene complexes, the bulky trityl ([CPh3]+) electrophile reacted with [M(C≡C-1,4-C6H4-C≡CH)(LL)Cp’] [M(LL)Cp’=Ru(PPh3)2Cp (4 a); Ru(dppe)Cp* (4 b); Fe(dppe)Cp (4 c); Fe(dppe)Cp* (4 d)] at the more exposed remote end of the carbon-rich ligand to give the putative quinoidal cumulene complexes [M{C=C=C6H4=C=C(H)CPh3}(LL)Cp’]+, which were isolated as the water adducts [M{C≡C-1,4-C6H4-C(=O)CH2CPh3}(LL)Cp’] (6 a–d). Evincing the scope of the formation of such extended cumulenes from ethynyl-substituted arylvinylene precursors, the rather reactive half-sandwich (5-ethynyl-2-thienyl)vinylidene complexes [M{C=C(H)-2,5-cC4H2S-C≡CH}(LL)Cp’]BF4 ([7 a–d]BF4 add water readily to give [M{C≡C-2,5-cC4H2S-C(=O)CH3}(LL)Cp’] (8 a–d)].

Synthesis and characterization of redox-active mononuclear Fe(κ2-dppe)(η5-C5Me 5)-Terminated π-conjugated wires

Several new redox-active Fe(κ2-dppe)(η5- C5Me5) arylacetylide complexes featuring pendant ethynyl (Fe(κ2-dppe)(η5-C5Me 5)[{Ci -C(1,4-C6H4)}n

Versatile reactions of a para-bromophenylacetylide iron (II) derivative and X-ray structure of the fluoro analogue. Synthesis of new redox-active organoiron (II) synthons

The synthesis of the new (η2-dppe) (η5-C5Me5) Fe-C≡C-1,3-(C6H4X) (m-2a/2b; X=F/Br) and (η2-dppe) (η5-C5Me5) Fe-C≡C-1,4-(C6H4I) (2c) complexes, as well as the solid-state structure of the known (η2-dppe)(η5-C5Me5) Fe-C≡C-1,4-(C6H4F) (2a) complex are described. The catalytic coupling reactions of the bromo complexes with various alkynes were next investigated. Starting from the known (η2-dppe)(η5-C5Me5) Fe-C≡C-1,4-(C6H4Br) complex (2b), the synthesis of the (η2-dppe)(η5-C5 Me5)Fe-C≡C-1,4-(C6H4)-C≡C-H complex (6d) and of the corresponding silyl-protected precursors (η2-dppe)(η5-C5Me5) Fe-C≡C-1,4-(C6H4)C≡C-SiR3 (6b/6c; R=iPr/Me) are reported. By use of lithium-bromine exchange reactions on 2b, the silyl- (7a; E=Si; R = Me) and tin- (7b-7d; E=Sn; R=Me, Bu, Ph) substituted analogues (η2-dppe) (η5-C5Me5)Fe-C≡C-1,4- (C6H4)ER3 are also isolated. The spectroscopic and electrochemical characterisations of all these new Fe(II)/Fe(III) redox-active building blocks are presented and the electronic substituent parameters for the (η2-dppe) (η5-C5Me5)Fe-C≡C group are determined by means of 19FNMR.