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Cyclopropyl building blocks in organic synthesis, part 143. A two-step, three-component queuing cascade leading to dihydrobenzoxepine and dihydrobenzazepine derivatives
A palladium-catalyzed reaction of methylenespiropentane (11) with iodobenzene (12) under typical Heck conditions [Pd(OAC)(2), PPh3, 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 pi-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 degrees 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 1...8-29 % only. The overall process constitutes a one-pot, two-step, three-component queuing cascade. (
Keywords:
pi-allylpalladium species / benzazepine / benzoxepine / bicyclopropylidene / methylenespiropentane
Source:
European Journal of Organic Chemistry, 2007, 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/123456789/1171
AB - A palladium-catalyzed reaction of methylenespiropentane (11) with iodobenzene (12) under typical Heck conditions [Pd(OAC)(2), PPh3, 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 pi-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 degrees 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-VCH Verlag Gmbh, Weinheim
T2 - European Journal of Organic Chemistry
T1 - Cyclopropyl building blocks in organic synthesis, part 143. A two-step, three-component queuing cascade leading to dihydrobenzoxepine and dihydrobenzazepine derivatives
EP - 4090
IS - 24
SP - 4081
VL - 2007
DO - 10.1002/ejoc.200700354
UR - conv_2867
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), PPh3, 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 pi-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 degrees 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-VCH Verlag Gmbh, Weinheim",
journal = "European Journal of Organic Chemistry",
title = "Cyclopropyl building blocks in organic synthesis, part 143. A two-step, three-component queuing cascade leading to dihydrobenzoxepine and dihydrobenzazepine derivatives",
pages = "4090-4081",
number = "24",
volume = "2007",
doi = "10.1002/ejoc.200700354",
url = "conv_2867"
}
Yucel, B., Valentić, N., Noltemeyer, M.,& de Meijere, A.. (2007). Cyclopropyl building blocks in organic synthesis, part 143. A two-step, three-component queuing cascade leading to dihydrobenzoxepine and dihydrobenzazepine derivatives. in European Journal of Organic Chemistry
Wiley-VCH Verlag Gmbh, Weinheim., 2007(24), 4081-4090.
https://doi.org/10.1002/ejoc.200700354
conv_2867
Yucel B, Valentić N, Noltemeyer M, de Meijere A. Cyclopropyl building blocks in organic synthesis, part 143. A two-step, three-component queuing cascade leading to dihydrobenzoxepine and dihydrobenzazepine derivatives. in European Journal of Organic Chemistry. 2007;2007(24):4081-4090.
doi:10.1002/ejoc.200700354
conv_2867 .
Yucel, Baris, Valentić, Nataša, Noltemeyer, Mathias, de Meijere, Armin, "Cyclopropyl building blocks in organic synthesis, part 143. A two-step, three-component queuing cascade leading to dihydrobenzoxepine and dihydrobenzazepine derivatives" in European Journal of Organic Chemistry, 2007, no. 24 (2007):4081-4090,
https://doi.org/10.1002/ejoc.200700354 .,
conv_2867 .
