Publicaciones > Valencia et al

Synthesis 2023, 55, 1260-1266. doi: 10.1055/a-1979-6009

Synthesis of Five-Membered Organoborate Heterocycles via a Metal-Free Carboboration and Their Use in Cross-Coupling Reactions.

Isabel Valencia, David Sucunza, Patricia García-García, Adrián Pérez-Redondo, Juan J. Vaquero

Palabras clave: metal-free carboboration; organoboron compounds; organoborate heterocycles; cross-coupling reactions; boron chemistry

Resumen

Treatment of various vinylbenzopyridines with allyl(dichloro)borane affords five-membered organoborate heterocycles via a metal-free carboboration. The reaction between these organoborates and Grignard reagents increases the number of derivatives belonging to this novel family of four-coordinate organoboron compounds. Some of them were used as reagents in phenylations and methylations in moderate to high yields under standard palladium-catalyzed cross-coupling reaction conditions.

Publicaciones > Sans-Panadés et al

Org Lett. 2022;24(31):5860-5865. doi: 10.1021/acs.orglett.2c02477. PubMed 35913827

Synthesis of BN-Polyarenes by a Mild Borylative Cyclization Cascade.

Ester Sans-Panadés, Juan J Vaquero, Manuel A Fernández-Rodríguez, Patricia García-García

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.

Abstract

Reaction of BCl(3) with suitably substituted o-alkynylanilines promotes a cascade reaction in which BN-polycyclic compounds are obtained via the formation of two new cycles and three new bonds in a single operational step. The reaction is highly efficient and takes place at room temperature, providing a very mild and straightforward strategy for the preparation of BN-aromatic compounds, which can be further transformed into a variety of BN-PAHs with different polycyclic cores and substituents.

Publicaciones > Valencia et al

J Org Chem. 2021 Nov 22. doi: 10.1021/acs.joc.1c01095. PubMed 34806882

1,10a-Dihydro-1-aza-10a-boraphenanthrene and 6a,7-Dihydro-7-aza-6a-boratetraphene: Two New Fluorescent BN-PAHs.

Isabel Valencia¹, Patricia García-García¹, David Sucunza¹, Francisco Mendicuti², Juan J Vaquero¹

1. Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, IRYCIS, Campus Científico-Tecnológico, 28805 Alcalá de Henares, Spain.  2. Departamento de Química Analítica, Química Física e Ingeniería Química, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, Campus Científico-Tecnológico, 28805 Alcalá de Henares, Spain.

Abstract

Previously unknown 1,10a-dihydro-1-aza-10a-boraphenanthrene and 6a,7-dihydro-7-aza-6a-boratetraphene have been efficiently synthesized. Bromination of these BN-PAHs proceeds with complete regioselectivity, resulting in the formation of different substituted derivatives via cross-coupling reactions. These compounds exhibit rather high fluorescence quantum yields (up to ϕ(F) = 0.80).

Publicaciones > Abengozar et al

Adv. Heterocycl. Chem. 2021 Mar 28; :197-259.

Recent developments in the chemistry of BN-aromatic hydrocarbons.

Alberto Abengozar, Patricia Garcia-Garcia, Manuel A. Fernández-Rodríguez, David Sucunza, Juan J Vaquero

Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química “Andrés M. del Río” (IQAR), Universidad de Alcalá (IRYCIS), Campus Científico-Tecnológico, Facultad de Farmacia, Alcalá de Henares, Madrid, Spain.

Abstract

Heterocycles containing both N and B heteroatoms in their structure were first reported by Dewar in the middle of the last century. However, they received little attention until the early years of this century, when several groups revisited these compounds due to their interest in BN/CC isosterism. As a result of these systematic studies, very significant advances have been made in our understanding of the chemistry of these BN-heterocycles. The purpose of this review is to summarize the most significant advances in the last two decades as regards the development of synthetic strategies and studies of their reactivity, as well as to provide an overview of their general properties and main applications.

Publicaciones > Abengozar et al

Chem Commun (Camb). 2020 Mar 28;56(25):3669-3672. doi: 10.1039/c9cc09998k.

Expanding the BN-embedded PAH family: 4a-aza-12a-borachrysene.

Alberto Abengozar¹, Isabel Valencia¹, Guillermo G Otarola¹, David Sucunza¹, Patricia Garcia-Garcia¹, Adrian Perez-Redondo¹, Francisco Mendicuti², Juan J Vaquero^1, a

1. Departamento de Quimica Organica y Quimica Inorganica, Instituto de Investigacion Quimica Andres M. del Rio (IQAR), Universidad de Alcala, IRYCIS, 28805 Alcala de Henares, Spain.  2. Departamento de Quimica Analitica, Quimica Fisica e Ingenieria Quimica, Universidad de Alcala, Spain.

a. david.sucunza@uah.es; juanjose.vaquero@uah.es

Abstract

Previously unknown 4a-aza-12a-borachrysene has been synthesized in only four steps. The reactions of this BN-embedded PAH with bromine and organolithium compounds proceed with complete regioselectivity, resulting in the formation of nine derivatives. One of these, a phenylalkynyl-substituted derivative, exhibits a remarkably high fluorescence quantum yield (PhiF %@3D 0.68).

Publicaciones > Abengozar et al

J Org Chem. 2019 Jun 7;84(11):7113-7122. doi: 10.1021/acs.joc.9b00800. Epub 2019 May 23. PubMed 31079459

A New Member of the BN-Phenanthrene Family: Understanding the Role of the B-N Bond Position.

Alberto Abengozar¹, David Sucunza¹, Patricia Garcia-Garcia¹, Diego Sampedro², Adrian Perez-Redondo¹, Juan J Vaquero¹

1. Departamento de Quimica Organica y Quimica Inorganica, Instituto de Investigacion Quimica "Andres M. del Rio" (IQAR) , Universidad de Alcala , 28805 Alcala de Henares , Spain.  2. Departamento de Quimica, Centro de Investigacion en Sintesis Quimica (CISQ) , Universidad de La Rioja , Madre de Dios 53 , 26006 Logrono , Spain.

Abstract

3,4-Dihydro-4-aza-3-boraphenanthrene, which shows the highest fluorescence quantum yield of all nonsubstituted BN-phenanthrenes reported to date (varphiF = 0.61), has been synthesized in only three steps (76% overall yield) from easily accessible 1-bromo-2-vinylnaphthalene, along with several substituted derivatives. The reactivity of these previously unknown BN-aromatic compounds toward organolithium compounds and bromine has been studied. This latter reaction affords bromo-substituted compounds that are suitable for further functionalization via Suzuki and Sonogashira couplings, with complete regioselectivity. The optical properties and excited state deactivation mechanisms of selected compounds were studied using computational methods.

Publicaciones > Abengozar et al

Beilstein J Org Chem. 2019 Jun 6;15:1257-1261. doi: 10.3762/bjoc.15.122. eCollection 2019. PubMed 31293672

Remarkable effect of alkynyl substituents on the fluorescence properties of a BN-phenanthrene.

Alberto Abengozar, David Sucunza, Patricia Garcia-Garcia, Juan J Vaquero

Departamento de Quimica Organica y Quimica Inorganica, Instituto de Investigacion Quimica "Andres M. del Rio" (IQAR), Universidad de Alcala, 28871-Alcala de Henares, Madrid, Spain.

Keywords: BN-phenanthrene; alkyne; cross-coupling; fluorescence; heterocycles

Abstract

A series of BN-phenanthrenes with substituents of a diverse nature have been synthesized by palladium-catalyzed cross-coupling reactions of a common chloro-substituted precursor, which was made from readily available materials in only four steps. Evaluation of the photophysical properties of the prepared compounds unveiled an impressive effect of the presence of alkynyl substituents on the fluorescence quantum yield, which improved from 0.01 in the parent compound to up to 0.65 in derivatives containing a triple bond.

Publicaciones > Abengozar et al

Org Lett. 2019 Apr 19;21(8):2550-2554. doi: 10.1021/acs.orglett.9b00448. Epub 2019 Apr 5. PubMed 30951317

Synthesis, Functionalization, and Optical Properties of 1,2-Dihydro-1-aza-2-boraphenanthrene and Several Highly Fluorescent Derivatives.

Alberto Abengozar¹, Patricia Garcia-Garcia¹, David Sucunza¹, Diego Sampedro², Adrian Perez-Redondo¹, Juan J Vaquero¹

1. Departamento de Quimica Organica y Quimica Inorganica, Instituto de Investigacion Quimica "Andres M. del Rio" (IQAR) , Universidad de Alcala , 28805 Alcala de Henares , Spain.  2. Departamento de Quimica, Centro de Investigacion en Sintesis Quimica (CISQ) , Universidad de La Rioja , Madre de Dios 53 , 26006 Logrono , Spain.

Abstract

Previously unknown 1,2-dihydro-1-aza-2-boraphenanthrene has been synthesized in only three steps from 2-bromo-1-vinylnaphthalene. The reactivity of this new BN-phenanthrene, and of several substituted derivatives, has been tested against bromine and organolithium compounds. Bromination proceeded with complete regioselectivity, affording bromo-substituted compounds suitable for further functionalization via cross-coupling reactions. This new family of BN-phenanthrenes exhibits a substantial increase in the quantum yield (up to varphiF = 0.93) with respect to phenanthrene.

Publicaciones > Abengozar et al

Org Lett. 2018 Aug 17;20(16):4902-4906. doi: 10.1021/acs.orglett.8b02040. PubMed 30070487

C-H Functionalization of BN-Aromatics Promoted by Addition of Organolithium Compounds to the Boron Atom.

Alberto Abengozar¹, Miguel Angel Fernandez-Gonzalez², David Sucunza¹, Luis Manuel Frutos², Antonio Salgado³, Patricia Garcia-Garcia¹, Juan J Vaquero¹

1. Departamento de Quimica Organica y Quimica Inorganica, Instituto de Investigacion Quimica "Andres M. del Rio" (IQAR) , Universidad de Alcala , 28805 Alcala de Henares , Madrid , Spain.  2. Departamento de Quimica Analitica, Quimica Fisica e Ingenieria Quimica, Instituto de Investigacion Quimica "Andres M. del Rio" (IQAR) , Universidad de Alcala , 28805 Alcala de Henares , Madrid , Spain.  3. Centro de Espectroscopia de Resonancia Magnetica Nuclear (CERMN), CAI Quimicas , Universidad de Alcala , 28805 Alcala de Henares , Madrid , Spain.

Abstract

Addition of an organolithium compound to a BN-phenanthrene with embedded B and N atoms is proposed to result in coordination of RLi to the boron atom. This coordination, supported by NMR spectroscopy and DFT calculations, increases the nucleophilicity of the system in the beta position to the N atom and is therefore a useful tool for promoting regioselective C-H functionalization of BN aromatics.

Publicaciones > Abengozar et al

Chem Commun (Camb). 2018 Mar 6;54(20):2467-2470. doi: 10.1039/c7cc09264d. PubMed 29319090

Synthesis of functionalized helical BN-benzo[c]phenanthrenes.

Alberto Abengozar^a, Patricia Garcia-Garcia, David Sucunza, Adrian Perez-Redondo, Juan J Vaquero

Departamento de Quimica Organica y Quimica Inorganica, Instituto de Investigacion Quimica "Andres M. del Rio" (IQAR), Universidad de Alcala, 28805-Alcala de Henares, Madrid, Spain.

a. patricia.garciagarci@uah.es, juanjose.vaquero@uah.es

Abstract

A novel parent BN-benzo[c]phenanthrene, with helical chirality and remarkable structural features, has been easily obtained in three steps with a global yield of 55%. Moreover, Cl-substituted derivatives have been prepared and these have served as useful starting materials for the development of palladium-catalyzed cross-coupling reactions.