A palladium-catalyzed reaction of methylenespiropentane (11) with iodobenzene (12) under typical Heck conditions [Pd(OAc)2, PPh 3, Et3N, DMF] produced a mixture of the unstable [3]dendralene 13 and allylidenecyclopropane 14 in 38 % yield. When an analogous reaction with iodobenzene was carried out in the presence of morpholine (25) and of tris(2-furyl)phosphane (TFP) instead of triphenylphosphane, the dienes 26, 28 and 31 were generated by nucleophilic trapping of π-allylpalladium intermediates 30 and 32. The cross coupling of methylenespiropentane (11) with the functionalized aryl iodides 33a-g in the presence of a palladium precatalyst [Pd(OAc)2, TFP, Et3N, DMF] at 80°C, 3 h, provided the seven-membered 3,4-dimethylene-substituted heterocycles 34a-g and 35b which, upon addition of dimethyl fumarate (19), underwent Diels-Alder reactions to furnish bicyclic and higher oligocyclic dihydrobenzoxepine and -benzazepine derivatives 36a-g and 37b, yet in rather moderate yields of 18-29% only.... The overall process constitutes a one-pot, two-step, three-component queuing cascade.
Keywords:
π-Allylpalladium species / Benzazepine; / Benzoxepine / Bicyclopropylidene / Methylenespiropentane
Source:
European Journal of Organic Chemistry, 2007, 24, 4081-4090
TY - JOUR
AU - Yucel, Baris
AU - Valentić, Nataša
AU - Noltemeyer, Mathias
AU - De Meijere, Armin
PY - 2007
UR - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5481
AB - A palladium-catalyzed reaction of methylenespiropentane (11) with iodobenzene (12) under typical Heck conditions [Pd(OAc)2, PPh 3, Et3N, DMF] produced a mixture of the unstable [3]dendralene 13 and allylidenecyclopropane 14 in 38 % yield. When an analogous reaction with iodobenzene was carried out in the presence of morpholine (25) and of tris(2-furyl)phosphane (TFP) instead of triphenylphosphane, the dienes 26, 28 and 31 were generated by nucleophilic trapping of π-allylpalladium intermediates 30 and 32. The cross coupling of methylenespiropentane (11) with the functionalized aryl iodides 33a-g in the presence of a palladium precatalyst [Pd(OAc)2, TFP, Et3N, DMF] at 80°C, 3 h, provided the seven-membered 3,4-dimethylene-substituted heterocycles 34a-g and 35b which, upon addition of dimethyl fumarate (19), underwent Diels-Alder reactions to furnish bicyclic and higher oligocyclic dihydrobenzoxepine and -benzazepine derivatives 36a-g and 37b, yet in rather moderate yields of 18-29% only. The overall process constitutes a one-pot, two-step, three-component queuing cascade.
PB - Wiley-Blackwell
T2 - European Journal of Organic Chemistry
T1 - A two-step, three-component queuing cascade leading to dihydrobenzoxepine and dihydrobenzazepine derivatives
EP - 4090
SP - 4081
VL - 24
DO - 10.1002/ejoc.200700354
ER -
@article{
author = "Yucel, Baris and Valentić, Nataša and Noltemeyer, Mathias and De Meijere, Armin",
year = "2007",
abstract = "A palladium-catalyzed reaction of methylenespiropentane (11) with iodobenzene (12) under typical Heck conditions [Pd(OAc)2, PPh 3, Et3N, DMF] produced a mixture of the unstable [3]dendralene 13 and allylidenecyclopropane 14 in 38 % yield. When an analogous reaction with iodobenzene was carried out in the presence of morpholine (25) and of tris(2-furyl)phosphane (TFP) instead of triphenylphosphane, the dienes 26, 28 and 31 were generated by nucleophilic trapping of π-allylpalladium intermediates 30 and 32. The cross coupling of methylenespiropentane (11) with the functionalized aryl iodides 33a-g in the presence of a palladium precatalyst [Pd(OAc)2, TFP, Et3N, DMF] at 80°C, 3 h, provided the seven-membered 3,4-dimethylene-substituted heterocycles 34a-g and 35b which, upon addition of dimethyl fumarate (19), underwent Diels-Alder reactions to furnish bicyclic and higher oligocyclic dihydrobenzoxepine and -benzazepine derivatives 36a-g and 37b, yet in rather moderate yields of 18-29% only. The overall process constitutes a one-pot, two-step, three-component queuing cascade.",
publisher = "Wiley-Blackwell",
journal = "European Journal of Organic Chemistry",
title = "A two-step, three-component queuing cascade leading to dihydrobenzoxepine and dihydrobenzazepine derivatives",
pages = "4090-4081",
volume = "24",
doi = "10.1002/ejoc.200700354"
}
Yucel, B., Valentić, N., Noltemeyer, M.,& De Meijere, A.. (2007). A two-step, three-component queuing cascade leading to dihydrobenzoxepine and dihydrobenzazepine derivatives. in European Journal of Organic Chemistry
Wiley-Blackwell., 24, 4081-4090.
https://doi.org/10.1002/ejoc.200700354
Yucel B, Valentić N, Noltemeyer M, De Meijere A. A two-step, three-component queuing cascade leading to dihydrobenzoxepine and dihydrobenzazepine derivatives. in European Journal of Organic Chemistry. 2007;24:4081-4090.
doi:10.1002/ejoc.200700354 .
Yucel, Baris, Valentić, Nataša, Noltemeyer, Mathias, De Meijere, Armin, "A two-step, three-component queuing cascade leading to dihydrobenzoxepine and dihydrobenzazepine derivatives" in European Journal of Organic Chemistry, 24 (2007):4081-4090,
https://doi.org/10.1002/ejoc.200700354 . .
