Dibenzo[d,d′]benzo[2,1-b:3,4-b′]difurans with extended π-conjugated chains: synthetic approaches and properties

Abstract

Ru-Catalysed reaction of 3,8-di(hexyn-1-yl)dibenzo[d,d']benzo[2,1-b,3,4-b′]difuran [3,8-di(hexyn-1-yl)-DBBDF] with 2 equivalents of methyl (E)-penta-2,4-dienoate produces 3,8-bis[(1E,3E,5E)-2-butyl-6-methoxycarbonylhexa-1,3,5-trien-1-yl]-DBBDF (9a).

Halogen-, oxidant- and directing group-free synthesis of donor–acceptor type conjugated polymers

“…According to these results and our previous cross-dimerisation between alkynes and dienes, 15 the present reaction is consistent with the mechanism shown in Scheme 1. First, the 6π coordinated naphthalene dissociates from the Ru(0) centre, and the 4π diene and the 2π alkyne coordinate to satisfy the 18-electron rule.…”

“…Note that an aryl ligand favours the α-position (substituent Ar 1 ) in B , according to our previous studies. 15 Then, the diastereoselective β -hydride elimination occurs to give C . The reductive elimination gives a conjugated triene complex D and subsequent rearrangement of the coordination mode gives E .…”

Direct synthesis of conjugated tetraenes from 1,3-enynes with 1,3-dienes

“…A similar trend in the regioselectivity of the aryl groups has been observed in previous cross-dimerisations of arylalkynes with conjugated dienes. 27,28 The benzylidene fragment in 5ha was obtained as the E -form, which was confirmed by pNOESY experiments. Probably, some in situ generated hydridoruthenium species would promote the Z -to- E isomerisation.…”

“…This product was assigned based on the ethyl analogue ethyl (2 E ,4 E ,6 E ,8 E )-10-((tetrahydro-2 H -pyran-2-yl)oxy)deca-2,4,6,8-tetraenoate. 3,28 (2 E ,4 E ,6 E ,8 E )- 9pa : 1 H NMR (400 MHz, CDCl 3 ): δ 1.51–1.86 (m, 6H, 13-, 14-, 15-C H 2 ), 3.47–3.51 (m, 1H, 16-C H 2 ), 3.73 (s, 3H, CO 2 Me ), 3.82–3.88 (m, 1H, 16-C H ), 4.04 (dd, 2 J H–H = 13.5 Hz, 3 J H–H = 6.6 Hz, 1H, 10-C H 2 ), 4.30 (dd, 2 J H–H = 14.7 Hz, 3 J H–H = 5.5 Hz, 1H, 10-C H 2 ), 4.63 (t, 3 J H–H = 3.7 Hz, 1H, 12-C H ), 5.86 (d, 3 J H–H = 15.1 Hz, 1H, 2-C H ), 5.90 (dt, 3 J H–H = 14.7, 6.3 Hz, 1H, 9-C H ), 6.24–6.36 (m, 4H, 4-, 6-, 7- and 8-C H ), 6.56 (dd, 3 J H–H = 14.7, 11.0 Hz, 1H, 5-C H ), 7.30 (dd, 3 J H–H = 15.1, 11.5 Hz, 1H, 3-C H ). (2 E ,4 E ,6 Z ,8 E )- 9pa : 1 H NMR: δ 1.51–1.86 (m, 6H, 13-, 14-, 15-C H 2 ), 3.47–3.51 (m, 1H, 16-C H 2 ), 3.71 (s, 3H, CO 2 Me ), 3.82–3.88 (m, 1H, 16-C H 2 ), 4.07 (dd, 2 J H–H = 12.6 Hz, 3 J H–H = 6.6 Hz, 1H, 10-C H 2 ), 4.34 (dd, 2 J H–H = 14.7 Hz, 3 J H–H = 5.7 Hz, 1H, 10-C H 2 ), 4.65 (t, 3 J H–H = 3.9 Hz, 1H, 12-C H ), 5.89 (d, 3 J H–H = 14.8 Hz, 1H, 2-C H ), 5.90 (dt, 3 J H–H = 14.7, 6.3 Hz, 1H, 9-C H ), 6.05 (t, 3 J H–H = 11.0 Hz, 1H, 6-C H ), 6.17 (t, 3 J H–H = 11.0 Hz, 1H, 7-C H ), 6.32 (dd, 3 J H–H = 15.8, 10.3 Hz, 1H, 4-C H ), 6.76 (dd, 3 J H–H = 14.7, 11.5 Hz, 1H, 8-C H ), 6.99 (dd, 3 J H–H = 15.1, 11.9 Hz, 1H, 5-C H ), 7.35 (dd, 3 J H–H = 15.6, 11.5 Hz, 1H, 3-C H ).…”

Ru(0)-catalysed cross-dimerisation and -trimerisation of alkynyl- with butadienylheteroarenes

“…11 Note that an aryl ligand preferentially locates at the α-position (substituent R 1 ) in this metallacycle, according to our previous studies. 11,16 Then, β-hydride elimination occurs selectively from the endo diastereotopic methylene proton to give C . The reductive elimination gives a conjugated triene complex and the subsequent rearrangement of the coordination mode gives E .…”