TY - JOUR
T1 - Selective synthesis of trisubstituted pyrroles through the reactions of alkynyl Fischer carbene complexes with oxazolones
AU - López, Julio
AU - Velazco-Cabral, Iván
AU - Rodríguez-DeLeón, Eloy
AU - Villegas Gómez, Clarisa
AU - Delgado, Francisco
AU - Tamariz, Joaquín
AU - Arrieta, Ana
AU - Cossío, Fernando P.
AU - Vázquez, Miguel A.
N1 - Publisher Copyright:
This journal is © The Royal Society of Chemistry.
PY - 2020
Y1 - 2020
N2 - An efficient and simple synthesis of novel trisubstituted 1H-pyrroles 4a-qvia 1,3-dipolar cycloaddition of Δ3-trifluoromethyloxazolones 2a-d with both chromium and tungsten alkynyl Fischer carbene complexes (1a-h) is described. An unexpected and unreported -CF3 group elimination process was observed in the pyrrole structure. Our experimental and theoretical data suggested that the metal fragment may be responsible for this phenomenon. The dipolar cycloaddition proceeded efficiently to produce a single regioisomer, which was unambiguously established through NMR and single-crystal X-ray diffraction studies. Nevertheless, the reaction of alkynyl carbenes bearing an α,β,γ,δ-unsaturated moiety with excess oxazolone 2a produced a polycyclic compound 6 speculatively formed through a cascade reaction involving 1,6-, 1,4- and 1,2-nucleophilic addition steps.
AB - An efficient and simple synthesis of novel trisubstituted 1H-pyrroles 4a-qvia 1,3-dipolar cycloaddition of Δ3-trifluoromethyloxazolones 2a-d with both chromium and tungsten alkynyl Fischer carbene complexes (1a-h) is described. An unexpected and unreported -CF3 group elimination process was observed in the pyrrole structure. Our experimental and theoretical data suggested that the metal fragment may be responsible for this phenomenon. The dipolar cycloaddition proceeded efficiently to produce a single regioisomer, which was unambiguously established through NMR and single-crystal X-ray diffraction studies. Nevertheless, the reaction of alkynyl carbenes bearing an α,β,γ,δ-unsaturated moiety with excess oxazolone 2a produced a polycyclic compound 6 speculatively formed through a cascade reaction involving 1,6-, 1,4- and 1,2-nucleophilic addition steps.
UR - http://www.scopus.com/inward/record.url?scp=85078345725&partnerID=8YFLogxK
U2 - 10.1039/c9ob02411e
DO - 10.1039/c9ob02411e
M3 - Artículo
C2 - 31872193
AN - SCOPUS:85078345725
SN - 1477-0520
VL - 18
SP - 538
EP - 550
JO - Organic and Biomolecular Chemistry
JF - Organic and Biomolecular Chemistry
IS - 3
ER -