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The divergent total synthesis strategy can be successfully applied to the preparation of families of natural products using a common late-stage pluripotent intermediate. This approach is a powerful tool in organic synthesis as it offers opportunities for the efficient preparation of structurally related compounds. This article reviews the synthesis of the marine natural product aureol, as well as its use as a common intermediate in the divergent synthesis of other marine natural and non-natural tetracyclic meroterpenoids.
Antonio Rosales Martínez; Ignacio Rodríguez-García; Josefa López-Martínez. Divergent Strategy in Marine Tetracyclic Meroterpenoids Synthesis. Marine Drugs 2021, 19, 273 .
AMA StyleAntonio Rosales Martínez, Ignacio Rodríguez-García, Josefa López-Martínez. Divergent Strategy in Marine Tetracyclic Meroterpenoids Synthesis. Marine Drugs. 2021; 19 (5):273.
Chicago/Turabian StyleAntonio Rosales Martínez; Ignacio Rodríguez-García; Josefa López-Martínez. 2021. "Divergent Strategy in Marine Tetracyclic Meroterpenoids Synthesis." Marine Drugs 19, no. 5: 273.
In the last two decades, titanocene monochloride has been postulated as a monoelectronic transfer reagent capable of catalyzing an important variety of chemical transformations. In this Perspective, our contributions to this growing field of research are summarized and analyzed. Especially known have been our contributions in C-C bond formation reactions, hydrogen-atom transfer from water to radicals, and isomerization reactions, as well as the development of a catalytic cycle that has subsequently allowed the preparation of a great variety of natural terpenes. It is also worth mentioning our contribution in the postulation of this single-electron transfer agent (SET) as a new green catalyst with a broad range of applications in organic and organometallic chemistry. The most significant catalytic processes developed by other research groups are also briefly described, with special emphasis on the reaction mechanisms involved. Finally, a reflection is made on the future trends in the research of this SET, aimed at consolidating this chemical as a new green reagent that will be widely used in fine chemistry, green chemistry, and industrial chemical processes.
Antonio Rosales Martínez; Laura Pozo Morales; Emilio Díaz Ojeda; María Castro Rodríguez; Ignacio Rodríguez-García. The Proven Versatility of Cp2TiCl. The Journal of Organic Chemistry 2020, 86, 1311 -1329.
AMA StyleAntonio Rosales Martínez, Laura Pozo Morales, Emilio Díaz Ojeda, María Castro Rodríguez, Ignacio Rodríguez-García. The Proven Versatility of Cp2TiCl. The Journal of Organic Chemistry. 2020; 86 (2):1311-1329.
Chicago/Turabian StyleAntonio Rosales Martínez; Laura Pozo Morales; Emilio Díaz Ojeda; María Castro Rodríguez; Ignacio Rodríguez-García. 2020. "The Proven Versatility of Cp2TiCl." The Journal of Organic Chemistry 86, no. 2: 1311-1329.
A new concise general methodology for the synthesis of different tetracyclic meroterpenoids is reported: (±)‑aureol (1), the key intermediate of this general route. The synthesis of (±)‑aureol (1) was achieved in seven steps (28% overall yield) from (±)‑albicanol. The key steps of this route include a C–C bond-forming reaction between (±)‑albicanal and a lithiated arene unit and a rearrangement involving 1,2‑hydride and 1,2-methyl shifts promoted by BF3•Et2O as activator and water as initiator.
Antonio Rosales Martínez; Lourdes Enríquez; Martín Jaraíz; Laura Pozo Morales; Ignacio Rodríguez-García; Emilio Díaz Ojeda. A Concise Route for the Synthesis of Tetracyclic Meroterpenoids: (±)-Aureol Preparation and Mechanistic Interpretation. Marine Drugs 2020, 18, 441 .
AMA StyleAntonio Rosales Martínez, Lourdes Enríquez, Martín Jaraíz, Laura Pozo Morales, Ignacio Rodríguez-García, Emilio Díaz Ojeda. A Concise Route for the Synthesis of Tetracyclic Meroterpenoids: (±)-Aureol Preparation and Mechanistic Interpretation. Marine Drugs. 2020; 18 (9):441.
Chicago/Turabian StyleAntonio Rosales Martínez; Lourdes Enríquez; Martín Jaraíz; Laura Pozo Morales; Ignacio Rodríguez-García; Emilio Díaz Ojeda. 2020. "A Concise Route for the Synthesis of Tetracyclic Meroterpenoids: (±)-Aureol Preparation and Mechanistic Interpretation." Marine Drugs 18, no. 9: 441.
A concise synthetic approach to the bioactive marine natural product (±)-cyclozonarone has been reported from readily available epoxy-farnesol acetate. Key steps of this protocol include Cp2TiCl-catalyzed radical cascade cyclization of an epoxy-farnesol derivative and a Diels–Alder reaction between a 1,3-diene and p-benzoquinone.
Antonio Rosales Martínez; Laura Pozo Morales; Emilio Díaz Ojeda. Cp2TiCl-catalyzed, concise synthetic approach to marine natural product (±)-cyclozonarone. Synthetic Communications 2019, 49, 2554 -2560.
AMA StyleAntonio Rosales Martínez, Laura Pozo Morales, Emilio Díaz Ojeda. Cp2TiCl-catalyzed, concise synthetic approach to marine natural product (±)-cyclozonarone. Synthetic Communications. 2019; 49 (19):2554-2560.
Chicago/Turabian StyleAntonio Rosales Martínez; Laura Pozo Morales; Emilio Díaz Ojeda. 2019. "Cp2TiCl-catalyzed, concise synthetic approach to marine natural product (±)-cyclozonarone." Synthetic Communications 49, no. 19: 2554-2560.
A simple, mild and safe reduction of furfural to furfuryl alcohol by the Mn/2,4,6‐Coll.HCl/H2O system is described. An experimental study on the role played by each of the reagents involved in this reduction and DFT calculations are reported. With the aim to provide an explanation for the results obtained, a complete mechanism is proposed.
Antonio Rosales Martínez; María Castro Rodríguez; Martín Jaraíz; Lourdes Enríquez; Emilio Díaz Ojeda; Roman Nicolay Rodríguez Maecker; Felipe Cordobés Carmona; Laura Pozo Morales. Reduction of furfural by Mn/2,4,6‐Coll . HCl/H 2 O: Mechanistic aspects of this reaction. Applied Organometallic Chemistry 2019, 33, 1 .
AMA StyleAntonio Rosales Martínez, María Castro Rodríguez, Martín Jaraíz, Lourdes Enríquez, Emilio Díaz Ojeda, Roman Nicolay Rodríguez Maecker, Felipe Cordobés Carmona, Laura Pozo Morales. Reduction of furfural by Mn/2,4,6‐Coll . HCl/H 2 O: Mechanistic aspects of this reaction. Applied Organometallic Chemistry. 2019; 33 (7):1.
Chicago/Turabian StyleAntonio Rosales Martínez; María Castro Rodríguez; Martín Jaraíz; Lourdes Enríquez; Emilio Díaz Ojeda; Roman Nicolay Rodríguez Maecker; Felipe Cordobés Carmona; Laura Pozo Morales. 2019. "Reduction of furfural by Mn/2,4,6‐Coll . HCl/H 2 O: Mechanistic aspects of this reaction." Applied Organometallic Chemistry 33, no. 7: 1.
The development of Green Chemistry inevitably involves the development of green reagents. In this review, we highlight that Cp2TiCl is a reagent widely used in radical and organometallic chemistry, which shows, if not all, at least some of the 12 principles summarized for Green Chemistry, such as waste minimization, catalysis, safer solvents, toxicity, energy efficiency, and atom economy. Also, this complex has proved to be an ideal reagent for green C–C and C–O bond forming reactions, green reduction, isomerization, and deoxygenation reactions of several functional organic groups as we demonstrate throughout the review.
María Castro Rodríguez; Ignacio Rodríguez García; Roman Nicolay Rodríguez Maecker; Laura Pozo Morales; J. Enrique Oltra; Antonio Rosales Martínez. Cp2TiCl: An Ideal Reagent for Green Chemistry? Organic Process Research & Development 2017, 21, 911 -923.
AMA StyleMaría Castro Rodríguez, Ignacio Rodríguez García, Roman Nicolay Rodríguez Maecker, Laura Pozo Morales, J. Enrique Oltra, Antonio Rosales Martínez. Cp2TiCl: An Ideal Reagent for Green Chemistry? Organic Process Research & Development. 2017; 21 (7):911-923.
Chicago/Turabian StyleMaría Castro Rodríguez; Ignacio Rodríguez García; Roman Nicolay Rodríguez Maecker; Laura Pozo Morales; J. Enrique Oltra; Antonio Rosales Martínez. 2017. "Cp2TiCl: An Ideal Reagent for Green Chemistry?" Organic Process Research & Development 21, no. 7: 911-923.
A general method for the straightforward synthesis of exocyclic allenes on five‐, six‐, seven‐, and eight‐membered oxygen heterocycles is described. A Barbier‐type titanocene(III)‐catalyzed cyclization of propargyl halides with a pendant carbonyl group is the key step of the process. This reaction is compatible with many functional groups, and can be smoothly carried out under neutral and mild conditions at room temperature.
Natalia M. Padial; Carmen Hernández-Cervantes; Juan Muñoz-Bascón; Esther María Roldán Molina; Mireya García-Martínez; Ana Belén Ruiz-Muelle; Antonio Rosales; Míriam Álvarez-Corral; Manuel Muñoz Dorado; Ignacio Rodríguez-García; J. Enrique Oltra. Ti-Catalyzed Synthesis of Exocyclic Allenes on Oxygen Heterocycles. European Journal of Organic Chemistry 2016, 2017, 639 -645.
AMA StyleNatalia M. Padial, Carmen Hernández-Cervantes, Juan Muñoz-Bascón, Esther María Roldán Molina, Mireya García-Martínez, Ana Belén Ruiz-Muelle, Antonio Rosales, Míriam Álvarez-Corral, Manuel Muñoz Dorado, Ignacio Rodríguez-García, J. Enrique Oltra. Ti-Catalyzed Synthesis of Exocyclic Allenes on Oxygen Heterocycles. European Journal of Organic Chemistry. 2016; 2017 (3):639-645.
Chicago/Turabian StyleNatalia M. Padial; Carmen Hernández-Cervantes; Juan Muñoz-Bascón; Esther María Roldán Molina; Mireya García-Martínez; Ana Belén Ruiz-Muelle; Antonio Rosales; Míriam Álvarez-Corral; Manuel Muñoz Dorado; Ignacio Rodríguez-García; J. Enrique Oltra. 2016. "Ti-Catalyzed Synthesis of Exocyclic Allenes on Oxygen Heterocycles." European Journal of Organic Chemistry 2017, no. 3: 639-645.
Dedicated to Prof. Emilio Diaz Ojeda A synthesis of (±)-ambrox, a compound with delicious ambergris-type scent, is presented. The key step is a highly diastereoselective titanocene(III)-catalyzed radical tandem cyclization of a farnesol derivative.
Antonio Rosales; J. Enrique Oltra; L. A. R. Foley; Natalia M. Padial; Juan Muñoz-Bascón; Iris Sancho-Sanz; Esther Roldan-Molina; Laura Pozo-Morales; Adriana Irías-Álvarez; Roman Rodríguez-Maecker; Ignacio Rodríguez-García. Diastereoselective Synthesis of (±)-Ambrox by Titanium(III)-Catalyzed Radical Tandem Cyclization. Synlett 2015, 27, 369 -374.
AMA StyleAntonio Rosales, J. Enrique Oltra, L. A. R. Foley, Natalia M. Padial, Juan Muñoz-Bascón, Iris Sancho-Sanz, Esther Roldan-Molina, Laura Pozo-Morales, Adriana Irías-Álvarez, Roman Rodríguez-Maecker, Ignacio Rodríguez-García. Diastereoselective Synthesis of (±)-Ambrox by Titanium(III)-Catalyzed Radical Tandem Cyclization. Synlett. 2015; 27 (03):369-374.
Chicago/Turabian StyleAntonio Rosales; J. Enrique Oltra; L. A. R. Foley; Natalia M. Padial; Juan Muñoz-Bascón; Iris Sancho-Sanz; Esther Roldan-Molina; Laura Pozo-Morales; Adriana Irías-Álvarez; Roman Rodríguez-Maecker; Ignacio Rodríguez-García. 2015. "Diastereoselective Synthesis of (±)-Ambrox by Titanium(III)-Catalyzed Radical Tandem Cyclization." Synlett 27, no. 03: 369-374.
Antonio Rosales; Ignacio Rodriguez-Garcia; Juan Muñoz-Bascón; Esther María Roldán Molina; Natalia M. Padial; Laura Pozo Morales; Marta García-Ocaña; J. Enrique Oltra. The Nugent-RajanBabu Reagent: A Formidable Tool in Contemporary Radical and Organometallic Chemistry. European Journal of Organic Chemistry 2015, 2015, 4592 -4592.
AMA StyleAntonio Rosales, Ignacio Rodriguez-Garcia, Juan Muñoz-Bascón, Esther María Roldán Molina, Natalia M. Padial, Laura Pozo Morales, Marta García-Ocaña, J. Enrique Oltra. The Nugent-RajanBabu Reagent: A Formidable Tool in Contemporary Radical and Organometallic Chemistry. European Journal of Organic Chemistry. 2015; 2015 (21):4592-4592.
Chicago/Turabian StyleAntonio Rosales; Ignacio Rodriguez-Garcia; Juan Muñoz-Bascón; Esther María Roldán Molina; Natalia M. Padial; Laura Pozo Morales; Marta García-Ocaña; J. Enrique Oltra. 2015. "The Nugent-RajanBabu Reagent: A Formidable Tool in Contemporary Radical and Organometallic Chemistry." European Journal of Organic Chemistry 2015, no. 21: 4592-4592.
The vast range of reactions mediated by titanocene monochloride (Cp2TiCl, the Nugent reagent) in organic synthetic chemistry is reviewed. The power of the Nugent reagent in organic chemistry is demonstrated by its ability to promote and/or catalyse several efficient transformations under mild reaction conditions in the presence of several functional groups, in an environmentally friendly manner and with use of simple experimental procedures.
Antonio Rosales; Ignacio Rodriguez-Garcia; Juan Muñoz-Bascón; Esther María Roldán Molina; Natalia M. Padial; Laura Pozo Morales; Marta García-Ocaña; J. Enrique Oltra. The Nugent Reagent: A Formidable Tool in Contemporary Radical and Organometallic Chemistry. European Journal of Organic Chemistry 2015, 2015, 4567 -4591.
AMA StyleAntonio Rosales, Ignacio Rodriguez-Garcia, Juan Muñoz-Bascón, Esther María Roldán Molina, Natalia M. Padial, Laura Pozo Morales, Marta García-Ocaña, J. Enrique Oltra. The Nugent Reagent: A Formidable Tool in Contemporary Radical and Organometallic Chemistry. European Journal of Organic Chemistry. 2015; 2015 (21):4567-4591.
Chicago/Turabian StyleAntonio Rosales; Ignacio Rodriguez-Garcia; Juan Muñoz-Bascón; Esther María Roldán Molina; Natalia M. Padial; Laura Pozo Morales; Marta García-Ocaña; J. Enrique Oltra. 2015. "The Nugent Reagent: A Formidable Tool in Contemporary Radical and Organometallic Chemistry." European Journal of Organic Chemistry 2015, no. 21: 4567-4591.
Material y métodos Estudio retrospectivo de 145 embarazos múltiples de ciclos de ICSI realizados entre el 1/01/2004 y el 31/12/2008, las pacientes fueron divididas en dos grupos (112 no evanescentes y 33 con saco/s evanescentes). Se realizó seguimiento ecográfico de las embarazadas y los parámetros se recogieron de la base de datos del centro. Posteriormente realizamos un estudio de casos-controles histórico para analizar los resultados neonatales de los embarazos simples procedentes de evanescentes, comparando con un grupo control de nacimientos procedentes de embarazos simples obtenido mediante técnicas de reproducción asistida (TRA) en nuestro centro que fueron registrados en el mismo período de estudio (n = 163). Resultados La tasa de evanescencia se situó en un 22,7%, siendo de un 17,5% en embarazos gemelares y de un 50% en embarazos triples. La evanescencia en los embarazos múltiples fue significativamente menor en el grupo con dos sacos gestacionales que en el grupo con tres o más sacos gestacionales (p < 0,001). Los resultados perinatales de los nacidos vivos en embarazos con evanescencia fueron similares a los obtenidos en nacidos procedentes de embarazos inicialmente simples. La tasa de embriones de buena calidad fue significativamente mayor en el grupo sin evanescentes (p < 0,001). No se observaron diferencias en términos de edad y de calidad seminal entre los grupos de estudio. Conclusiones La tasa de evanescencia embrionaria aumenta significativamente en los embarazos de más de dos sacos gestacionales, existiendo una relación entre este fenómeno y la calidad de la transferencia embrionaria. Abstract Background The vanishing embryo phenomenon is defined as the spontaneous loss of one or more embryos in a multiple pregnancy without its interruption. The aim of this study was to determine the rate of vanishing embryo syndrome in women with multiple pregnancies conceived by Intracytoplasmic Sperm Injection (ICSI), to analyse the evolution of these pregnancies, and to find a relationship with possible causes, such as embryo and seminal quality. Material and methods A retrospective analysis was performed of 145 multiple pregnancies conceived by ICSI, from January 2004 to December 2008. They were divided in two groups (112 without vanishing syndrome and 33 with any embryo suffering from vanishing syndrome). We then carried out a case-control study in order to compare the neonatal results of single pregnancies with vanishing embryo syndrome. We carried out transvaginal ultrasound monitoring until 12 weeks of gestation. The data were obtained from the centre data base. Results Vanishing embryo syndrome was observed in 22.7% of our patients, with 17.5% of cases being observed in twin pregnancies, and 50% in triple pregnancies. The vanishing embryo rate in multiple pregnancies was significantly lower in the group with two gestational sacs than in the group with three or more gestational sacs ( P < .001). The rate of good quality embryos was significantly higher in the group without vanishing embryos ( P < .001). No differences were observed in terms of age and seminal quality among study groups. Perinatal outcomes of live births were similar in both groups. Conclusion Vanishing embryos rate seems to increase in pregnancies with over two gestational sacs. We observed a relationship between this syndrome and embryo transfer quality. Palabras clave Reabsorción del embrión Inyección de esperma intracitoplasmática Embarazo múltiple Peso al nacer Keywords Embryo loss Intracytoplasmic sperm injection Multiple pregnancy Birth weight Introducción La evanescencia embrionaria, también llamada reducción embrionaria espontánea o síndrome del embrión evanescente, se puede definir como la desaparición espontánea de uno o más embriones durante una gestación múltiple con posterior reabsorción del saco gestacional sin que el embarazo sea interrumpido. Puede producirse en cualquier momento de la gestación, aunque suele ocurrir en la segunda mitad del primer trimestre o al inicio del segundo 1 . Este fenómeno ha sido observado por numerosos autores y puede tener lugar tanto en gestaciones espontáneas como en gestaciones que se producen tras la aplicación de técnicas de reproducción asistida 2,3 . Si consideramos los criterios adoptados para definir evanescencia, encontramos discrepancia entre los distintos autores: el fenómeno de la evanescencia puede implicar que desaparezca el saco vacío, el saco con el polo embrionario 4 o el saco con un embrión en el que previamente se observó latido cardiaco 5 . Aunque se ha intentado relacionar la evanescencia embrionaria con distintas causas, la fisiopatología sigue siendo desconocida. Existen varios estudios que intentan analizar posibles factores etiológicos que permitan pronosticar cuando se producirá dicho fenómeno. Entre las características estudiadas se encuentran parámetros propios de la pareja (edad, índice de masa corporal, número de años de esterilidad, anormalidades uterinas, número de folículos basales antrales), parámetros del proceso de reproducción asistida (número de sacos gestacionales, número de embriones transferidos e implantados, número de ovocitos obtenidos, maduros y fecundados, grosor del endometrio), y parámetros de laboratorio (seminograma, calidad embrionaria) 6–8 . Incluso se han analizado factores embrionarios como cariotipo anormal 9,10 , placenta triploide 11 , placenta quimérica 12 y anomalías fetales como la siringomielia 13 . Sin embargo, de todos estos parámetros, los únicos en...
Maria Paz Roldán Ramírez; Ana Clavero Gilabert; M. Carmen Gonzalvo López; Beatriz González Soto; Antonio Rosales Martínez; Jose Antonio Castilla Alcalá. Influencia de la calidad embrionaria y seminal en el síndrome del embrión evanescente. Revista del Laboratorio Clínico 2011, 4, 70 -76.
AMA StyleMaria Paz Roldán Ramírez, Ana Clavero Gilabert, M. Carmen Gonzalvo López, Beatriz González Soto, Antonio Rosales Martínez, Jose Antonio Castilla Alcalá. Influencia de la calidad embrionaria y seminal en el síndrome del embrión evanescente. Revista del Laboratorio Clínico. 2011; 4 (2):70-76.
Chicago/Turabian StyleMaria Paz Roldán Ramírez; Ana Clavero Gilabert; M. Carmen Gonzalvo López; Beatriz González Soto; Antonio Rosales Martínez; Jose Antonio Castilla Alcalá. 2011. "Influencia de la calidad embrionaria y seminal en el síndrome del embrión evanescente." Revista del Laboratorio Clínico 4, no. 2: 70-76.