TY - JOUR
T1 - Synthesis of novel 2,5-substituted p-aminophenols and 2,5-substituted p-quinones in a one-pot reaction between α-alkoxyvinyl(ethoxy)carbene complexes, amines and alkynes
AU - Feliciano, Alberto
AU - Padilla, Rosa
AU - Escalante, Carlos H.
AU - Herbert-Pucheta, José Enrique
AU - Vázquez, Miguel A.
AU - Tamariz, Joaquín
AU - Delgado, Francisco
N1 - Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/9/15
Y1 - 2020/9/15
N2 - The synthesis of novel p-aminophenols 19a-o and p-quinones 21a-i was carried out by an aminolysis reaction/[3 + 2+1] cycloaddition cascade process of α-alkoxyvinyl (ethoxy) Fischer carbene complexes of group 6 metals (M = Cr, Mo, W), primary and secondary amines and terminal alkynes. The multicomponent reaction of carbenes 1a-c with morpholine (6a) and piperidine (6c), respectively, and terminal alkynes 17a-d only afforded the 4-aminophenols 19a-o in moderated yields. The products bore the terminal alkyne substituent at the ortho position of the hydroxyl group. These one-pot reactions showed highly regio- and chemoselectivity, favoring the benzannulation products. When carbene complexes 1a-c were reacted with primary amines 10a-c and alkynes 17a-c under the same conditions, the cascade process led to the formation of p-quinones 21a-21i, in moderate yields. The regiochemistry of the compounds was established by NOE experiments, and the structures of morpholinocarbene 7a, p-aminophenols 19b, 19d and p-quinone 21b were confirmed by single-crystal X-ray diffraction.
AB - The synthesis of novel p-aminophenols 19a-o and p-quinones 21a-i was carried out by an aminolysis reaction/[3 + 2+1] cycloaddition cascade process of α-alkoxyvinyl (ethoxy) Fischer carbene complexes of group 6 metals (M = Cr, Mo, W), primary and secondary amines and terminal alkynes. The multicomponent reaction of carbenes 1a-c with morpholine (6a) and piperidine (6c), respectively, and terminal alkynes 17a-d only afforded the 4-aminophenols 19a-o in moderated yields. The products bore the terminal alkyne substituent at the ortho position of the hydroxyl group. These one-pot reactions showed highly regio- and chemoselectivity, favoring the benzannulation products. When carbene complexes 1a-c were reacted with primary amines 10a-c and alkynes 17a-c under the same conditions, the cascade process led to the formation of p-quinones 21a-21i, in moderate yields. The regiochemistry of the compounds was established by NOE experiments, and the structures of morpholinocarbene 7a, p-aminophenols 19b, 19d and p-quinone 21b were confirmed by single-crystal X-ray diffraction.
KW - Dötz reaction
KW - Multicomponent reaction
KW - p-Quinones
KW - p-aminophenols
KW - α-alkoxyvinyl(ethoxy)carbene complexes
UR - http://www.scopus.com/inward/record.url?scp=85089085905&partnerID=8YFLogxK
U2 - 10.1016/j.jorganchem.2020.121360
DO - 10.1016/j.jorganchem.2020.121360
M3 - Artículo
AN - SCOPUS:85089085905
SN - 0022-328X
VL - 923
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
M1 - 121360
ER -