Bi- and poly(carbyne) functionalised polycyclic aromatics

Abstract

The Pd0/AuI-mediated coupling between a tungsten stannylcarbyne and a diverse range of aryl halides has allowed from one to four carbynes to be appended to, and bridged by, central aromatic ring systems including fused polycyclic examples.

Propargylidyne and Pentadiynylidyne Polyfunctionalised Polycyclic Aromatic Hydrocarbons

“…The 1 H and 13 C{ 1 H} NMR spectra include signals relating to the Tp* ligand in the usual 2:1 ratio (local C s ‐symmetry). Five proton resonances and eight carbon resonances correspond to the anthracenyl terminus in 2 , which contrasts with the restricted rotation of the anthracenyl group inferred for the shorter C 1 analogue [9‐{(Tp*)(CO) 2 W≡C}C 14 H 9 ] . Along the W≡CαCβ≡Cγ propargylidyne chain, the carbon nuclei resonate at δ C =245.3(α), 118.6(β) and 67.5(γ), respectively, in 2 and at δ C =246.0, 113.1 and 69.9, respectively, in 3 , well within the expected range for aryl‐terminated propargylidynes…”

“…Five proton resonances and eight carbon resonances correspondt ot he anthracenyl terminus in 2,w hich contrasts with the restricted rotation of the anthracenyl group inferred for the shorter C 1 analogue [9-{(Tp*)(CO) 2 W C}C 14 H 9 ]. [10] Along the W CaCb Cg propargylidyne chain, the carbonn ucleiresonate at d C = 245.3(a), 118.6(b)a nd 67.5(g), respectively,i n2 and at d C = 246.0, 113.1 and6 9.9, respectively, in 3,w ellw ithin the expected range for aryl-terminated propargylidynes. [3] The molecular structure of 2 ( Figure 1) reveals localised, alternating single and triple bondsa long the propargylidyne spine.…”

“…1.363(8)1.377(10)1 .363 7r Cb-Cg [b] 1.220(9)1.202(10)1 .220(8) W CÀC [c] 173.7(5)171.0(6) 173.5(5) n CO (50 %d isplacement ellipsoids, crystallographic inversion centres (4: 1 = 2 , 1 = 2 ,0; 5:0,0, 1 = 2 )i ng reen, hydrogen atomso mitted and pyrazolyl groups simplified). Selectedd istances []and angles [ 8]: (a) For 4:W1 ÀC1 1.849 7, C1ÀC4 1.377(10), C4ÀC5 1.202 (10), C5À C6 1.423 9, W1-C1-C4 171.0(6), C1-C4-C5 177.8 (8), C4-C5-C61 76.7 (7). (b) For 5:W1-C11.842 5, C1-C4 1.363 7, C4-C51 .220(8),C 5-C6 1.418 7, W1-C1-C4 173.5(5), C4-C5-C6 176.9(6), C1-C4-C51 77.3 (6).…”

Heterobimetallic μ2-halocarbyne complexes

“…In such processes, the bromocarbyne serves as the C -electrophile partner in combination with a range of nucleophiles. Alternatively, conversion of the halocarbyne to the stannyl derivatives [M(CSnR 3 )(CO) 2 (Tp*)] (M = Mo, W; R = Me, n Bu) 48 allows the carbyne to serve the C -nucleophile role. Implicit in the former strategy is the intermediacy of heterobimetallic μ-carbido complexes of the form [MPd(μ 2 -C)Br(CO) 2 (PPh 3 ) 2 (Tp*)].…”

Transition Metal Carbide Complexes

“…432 For example, BCl(NMe 2 ) 2 , BCl(cat), and BCl(OMe 433 In terms of reactivity, [(Tp′)(OC) 2 MC−Li] (M = Mo, W) complexes show parallels to acetylides. For instance, SnClBu 3 provides access to the stannyl-functionalized carbide, [(Tp′)-(OC) 2 WC−SnBu 3 ], which engages in Stille coupling reactions with pyridyl, 434 bipyridyl, 435 and (polycyclic) aryl 436 halides as substrates (Figure 81). This provides a wide range of mono-and polycarbyne complexes, including porphyrins decorated with peripheral aryl-carbyne groups.…”