Publicaciones > Garre et al

Org Biomol Chem. 2023,21,2705-2708. doi: 10.1039/d3ob00051f. PubMed 36919647

Gold-catalyzed endo-selective cyclization of alkynylcyclobutanecarboxamides: synthesis of cyclobutane-fused dihydropyridones.

M Soledad Garre^1, a, Guillermo G Otárola^1, b, Estíbaliz Merino^1, c, David Sucunza^1, d, Enrique Aguilar², M Teresa Quirós^1, e, Juan J Vaquero^1, f, Patricia García-García^1, g

1. Universidad de Alcalá (IRYCIS), Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Campus Científico-Tecnológico, Facultad de Farmacia, Autovía A-II, Km 33.1, 28805-Alcalá de Henares, Madrid, Spain.  2. Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica "Enrique Moles", Universidad de Oviedo, C/Julián Clavería, 8, 33006 Oviedo, Spain.

a. juanjose.vaquero@uah.es  b. juanjose.vaquero@uah.es  c. juanjose.vaquero@uah.es  d. juanjose.vaquero@uah.es  e. juanjose.vaquero@uah.es  f. juanjose.vaquero@uah.es  g. juanjose.vaquero@uah.es

Abstract

Cyclobutane-fused dihydropyridones can be efficiently synthesized by a completely endo-selective gold-catalyzed cyclization of alkynylcyclobutanes bearing an appended amide, which proceeds under mild conditions. The observed selectivity, which is reversed from that previously observed for the cyclization of related alcohols and acids, is supported by DFT calculations.

Publicaciones > Milián et al

Org Lett. 2020 Nov 6;22(21):8464-8469. doi: 10.1021/acs.orglett.0c03067.

Selective Synthesis of Phenanthrenes and Dihydrophenanthrenes via Gold-Catalyzed Cycloisomerization of Biphenyl Embedded Trienynes.

Ana Milián¹, Patricia García-García¹, Adrián Pérez-Redondo¹, Roberto Sanz², Juan J Vaquero¹, Manuel A Fernández-Rodríguez¹

1. Departamento de Quı́mica Orgánica y Quı́mica Inorgánica, Instituto de Investigación Quı́mica "Andrés M. del Rı́o" (IQAR). Universidad de Alcalá (IRYCIS). Campus Cientı́fico-Tecnológico, Facultad de Farmacia, Autovía A-II, Km 33.1, 28805 Alcalá de Henares, Madrid, Spain.  2. Área de Quı́mica Orgánica, Departamento de Quı́mica, Facultad de Ciencias, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.

Abstract

Readily available o'-alkenyl-o-alkynylbiaryls, a particular type of 1,7-enynes, undergo a selective cycloisomerization reaction in the presence of a gold(I) catalyst to give interesting phenanthrene and dihydrophenanthrene derivatives in high yields. The solvent used provokes a switch in the evolution of the gold intermediate and plays a key role in the reaction outcome.

Publicaciones > Otarola et al

Catalysts. 2020 Oct 8; 22(21):1178.

Gold-Catalyzed Synthetic Strategies towards Four-Carbon Ring Systems.

Guillermo G Otarola, Juan J Vaquero, Estíbaliz Merino, Manuel A Fernández-Rodríguez

Departamento de Quı́mica Orgánica y Quı́mica Inorgánica, Instituto de Investigación Quı́mica "Andrés M. del Rı́o" (IQAR). Universidad de Alcalá (IRYCIS). Campus Cientı́fico-Tecnológico, Facultad de Farmacia, Autovía A-II, Km 33.1, 28805 Alcalá de Henares, Madrid, Spain.

Abstract

Four carbon ring systems are frequently present in natural products with remarkable biological activities such as terpenoids, alkaloids, and steroids. The development of new strategies for the assembly of these structures in a rapid and efficient manner has attracted the interest of synthetic chemists for a long time. The current research is focused mainly on the development of synthetic methods that can be performed under mild reaction conditions with a high tolerance to functional groups. In recent years, gold complexes have turned into excellent candidates for this aim, owing to their high reactivity, and are thus capable of promoting a wide range of transformations under mild conditions. Their remarkable efficiency has been thoroughly demonstrated in the synthesis of complex organic molecules from simple starting materials. This review summarizes the main synthetic strategies described for gold-catalyzed four-carbon ring formation, as well as their application in the synthesis of natural products.

Publicaciones > Garre et al

J Org Chem. 2019 Apr 18. doi: 10.1021/acs.joc.9b00618. PubMed 30896164

Regiodivergent Electrophilic Cyclizations of Alkynylcyclobutanes for the Synthesis of Cyclobutane-Fused O-Heterocycles.

M Soledad Garre¹, David Sucunza¹, Enrique Aguilar², Patricia Garcia-Garcia¹, Juan J Vaquero¹

1. Departamento de Quimica Organica y Quimica Inorganica, Campus Cientifico-Tecnologico, Facultad de Farmacia , Universidad de Alcala (IRYCIS) , Autovia A-II, Km 33.1 , 28805 Alcala de Henares , Madrid , Spain.  2. Departamento de Quimica Organica e Inorganica, Instituto Universitario de Quimica Organometalica "Enrique Moles" , Universidad de Oviedo , C/Julian Claveria, 8 , 33006 Oviedo , Spain.

Abstract

Cyclobutane-fused dihydropyrans and methylenetetrahydrofurans are highly interesting cores found in numerous natural products. Both these cores are selectively prepared from a common alkynylcyclobutane precursor bearing an appended hydroxyl group herein. Thus, cyclobutane-fused dihydropyrans can be obtained by a selective 6-endo-dig iodocyclization, whereas gold-catalyzed 5-exo-dig cycloisomerization provides a bicyclic core containing a methylenetetrahydrofuran moiety as major product. Several cyclobutane-fused O-heterocycles with diverse substituents are synthesized following the reported methodology.