TY - JOUR
T1 - Highly selective Diels–Alder and Heck arylation reactions in a divergent synthesis of isoindolo- And pyrrolo-fused polycyclic indoles from 2-formylpyrrole
AU - Escalante, Carlos H.
AU - Martínez-Mora, Eder I.
AU - Espinoza-Hicks, Carlos
AU - Camacho-Dávila, Alejandro A.
AU - Ramos-Morales, Fernando R.
AU - Delgado, Francisco
AU - Tamariz, Joaquín
N1 - Publisher Copyright:
© 2020 Escalante et al.
PY - 2020/6/17
Y1 - 2020/6/17
N2 - A highly regio-, chemo- and stereoselective divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles is herein described, starting from 2-formylpyrrole and employing Diels–Alder and Heck arylation reactions. 3-(N-Benzyl-2-pyrrolyl)acrylates and 4-(pyrrol-2-yl)butenones underwent a highly endo-Diels–Alder cycloaddition with maleimides to furnish octahydropyrrolo[3,4e]indoles, which served as precursors in the regioselective synthesis of aza-polycyclic skeletons via an intramolecular Heck arylation reaction. Through the latter reaction, the 3-(N-benzyl-2-pyrrolyl)acrylates give rise to 3-(pyrrolo[2,1-a]isoindol-3-yl)acrylates. A further oxidative aromatization of the polycyclic intermediates provides the corresponding polycyclic pyrrolo-isoindoles and isoindolo-pyrrolo-indoles. A theoretical study on the stereoselective Diels–Alder reactions, carried out by calculating the endo/exo transition states, revealed the assistance of non-covalent interactions in governing the endo stereocontrol.
AB - A highly regio-, chemo- and stereoselective divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles is herein described, starting from 2-formylpyrrole and employing Diels–Alder and Heck arylation reactions. 3-(N-Benzyl-2-pyrrolyl)acrylates and 4-(pyrrol-2-yl)butenones underwent a highly endo-Diels–Alder cycloaddition with maleimides to furnish octahydropyrrolo[3,4e]indoles, which served as precursors in the regioselective synthesis of aza-polycyclic skeletons via an intramolecular Heck arylation reaction. Through the latter reaction, the 3-(N-benzyl-2-pyrrolyl)acrylates give rise to 3-(pyrrolo[2,1-a]isoindol-3-yl)acrylates. A further oxidative aromatization of the polycyclic intermediates provides the corresponding polycyclic pyrrolo-isoindoles and isoindolo-pyrrolo-indoles. A theoretical study on the stereoselective Diels–Alder reactions, carried out by calculating the endo/exo transition states, revealed the assistance of non-covalent interactions in governing the endo stereocontrol.
KW - 2-formylpyrrole
KW - Endo-Diels–Alder stereocontrol
KW - Intramolecular Heck arylation reaction
KW - Non-covalent interactions
KW - Pyrroloindoles
KW - Pyrroloisoindoles
UR - http://www.scopus.com/inward/record.url?scp=85087525586&partnerID=8YFLogxK
U2 - 10.3762/bjoc.16.113
DO - 10.3762/bjoc.16.113
M3 - Artículo
AN - SCOPUS:85087525586
SN - 1860-5397
VL - 16
SP - 1320
EP - 1334
JO - Beilstein Journal of Organic Chemistry
JF - Beilstein Journal of Organic Chemistry
ER -