TY - JOUR
T1 - Versatile and regioselective synthesis of polysubstituted and highly oxygenated phenols via Dötz reaction of α-alkoxyvinyl(ethoxy)carbene complexes with alkynes
AU - Montenegro, Mabel M.
AU - Vega-Báez, José Luis
AU - Vázquez, Miguel A.
AU - Flores-Conde, Ma Inés
AU - Sánchez, Arturo
AU - González-Tototzin, Miguel A.
AU - Gutiérrez, Rsuini U.
AU - Lazcano-Seres, J. Miguel
AU - Ayala, Francisco
AU - Zepeda, L. Gerardo
AU - Tamariz, Joaquín
AU - Delgado, Francisco
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2016/12/15
Y1 - 2016/12/15
N2 - A comparative study of reactivity and selectivity of α-alkoxyvinyl(ethoxy) Fischer carbene complexes (CO)5M = C[C(=CHR1)(OR)]OCH2CH3 [7a–d: M = Cr; 12a–c: M = Mo; 13a–d: M = W; a: R1 = H, R = CH2CH3; b: R1 = H, R = CH2CH2CH3; c: R1 = H, R = CH2CH2CH2CH3; d: R1 = CH3, R = Et (E and Z)] with terminal and internal alkynes (14a–g) in benzannulation reactions is described. The complexes 7 and 12–13 display a remarkable reactivity toward different alkynes. The [3 + 2+1] cycloaddition or benzannulation reactions between the latter carbene complexes and alkynes 14 were found to be highly regio- and chemoselective only giving those products with the largest substituent of the acetylenic component located at the ortho position to the hydroxyl group, and favoring the formation of new and highly oxygenated and polysubstituted phenols containing only electron-donating groups. The regiochemistry assignment of the cycloadducts was supported by NOE measurements. Phenols 15c, 16e, and 18b were further characterized by single-crystal X-ray diffraction.
AB - A comparative study of reactivity and selectivity of α-alkoxyvinyl(ethoxy) Fischer carbene complexes (CO)5M = C[C(=CHR1)(OR)]OCH2CH3 [7a–d: M = Cr; 12a–c: M = Mo; 13a–d: M = W; a: R1 = H, R = CH2CH3; b: R1 = H, R = CH2CH2CH3; c: R1 = H, R = CH2CH2CH2CH3; d: R1 = CH3, R = Et (E and Z)] with terminal and internal alkynes (14a–g) in benzannulation reactions is described. The complexes 7 and 12–13 display a remarkable reactivity toward different alkynes. The [3 + 2+1] cycloaddition or benzannulation reactions between the latter carbene complexes and alkynes 14 were found to be highly regio- and chemoselective only giving those products with the largest substituent of the acetylenic component located at the ortho position to the hydroxyl group, and favoring the formation of new and highly oxygenated and polysubstituted phenols containing only electron-donating groups. The regiochemistry assignment of the cycloadducts was supported by NOE measurements. Phenols 15c, 16e, and 18b were further characterized by single-crystal X-ray diffraction.
KW - (α-Alkoxyvinyl)carbene complexes
KW - Dötz benzannulation
KW - Regioselective cycloaddition
KW - Trioxygenated and polysubstituted phenols
UR - http://www.scopus.com/inward/record.url?scp=84992663711&partnerID=8YFLogxK
U2 - 10.1016/j.jorganchem.2016.10.017
DO - 10.1016/j.jorganchem.2016.10.017
M3 - Artículo
SN - 0022-328X
VL - 825-826
SP - 41
EP - 54
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
ER -