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1.
Angew Chem Int Ed Engl ; 63(32): e202408419, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-38774966

RESUMEN

Despite the paramount importance of the Suzuki-Miyaura coupling (SMC) in academia and industry, and the great promise of iron to offer sustainable catalysis, iron-catalyzed SMC involving sp3-hybridized partners is still in its infancy. We herein report the development of a versatile, well-defined electron-deficient anilido-aldimine iron(II) catalyst. This catalyst effectively performed C(sp3)-C(sp2) and C(sp3)-C(sp3) SMC of alkyl halide electrophiles and (hetero)aryl boronic ester and alkyl borane nucleophiles respectively, in the presence of a lithium amide base. These couplings operated under mild reaction conditions and displayed wide functional group compatibility including various medicinally relevant N-, O- and S-based heterocycles. They also tolerated primary, secondary and tertiary alkyl halides (Br, Cl, I), electron-neutral, -rich and -poor boronic esters and primary and secondary alkyl boranes. Our methodology could be directly and efficiently applied to synthesize key intermediates relevant to pharmaceuticals and a potential drug candidate. For C(sp3)-C(sp2) couplings, radical probe experiments militated in favor of a carbon-centered radical derived from the electrophile. At the same time, reactions run with a pre-formed activated boron nucleophile coupled to competition experiments supported the involvement of neutral, rather than an anionic, (hetero)aryl boronic ester in the key transmetalation step.

2.
Molecules ; 22(11)2017 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-29113059

RESUMEN

This review provides an outline of the most noteworthy achievements in the area of C-N, C-O and C-P bond formation by hydroamination, hydroalkoxylation, hydrophosphination, hydrophosphonylation or hydrophosphinylation reaction on unactivated alkenes (including 1,2- and 1,3-dienes) promoted by first-row late transition metal catalytic systems based on manganese, iron, cobalt, nickel, copper and zinc. The relevant literature from 2009 until mid-2017 has been covered.


Asunto(s)
Alquenos/química , Metales/química , Catálisis
3.
Org Biomol Chem ; 9(2): 497-503, 2011 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-21069238

RESUMEN

New Yb(OTf)(3)-pyridylalkylamine complexes have been employed as chiral Lewis acids in the enantioselective Friedel-Crafts alkylation of indole derivatives with trifluoropyruvates. The influence of the substituents as well as the configuration of the ligands have been studied and allowed us to reach enantiomeric excesses up to 83%.

4.
Addict Sci Clin Pract ; 13(1): 27, 2018 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-30547847

RESUMEN

BACKGROUND: Medically complex urban patients experiencing homelessness comprise a disproportionate number of high-cost, high-need patients. There are few studies of interventions to improve care for these populations; their social complexity makes them difficult to study and requires clinical and research collaboration. We present a protocol for a trial of the streamlined unified meaningfully managed interdisciplinary team (SUMMIT) team, an ambulatory ICU (A-ICU) intervention to improve utilization and patient experience that uses control populations to address limitations of prior research. METHODS/DESIGN: Participants are patients at a Federally Qualified Health Center in Portland, Oregon that serves patients experiencing homelessness or who have substance use disorders. Participants meet at least one of the following criteria: > 1 hospitalization over past 6 months; at least one medical co-morbidity including uncontrolled diabetes, heart failure, chronic obstructive pulmonary disease, liver disease, soft-tissue infection; and 1 mental health diagnosis or substance use disorder. We exclude patients if they have < 6 months to live, have cognitive impairment preventing consent, or are non-English speaking. Following consent and baseline assessment, we randomize participants to immediate SUMMIT intervention or wait-list control group. Participants receiving the SUMMIT intervention transfer care to a clinic-based team of physician, complex care nurse, care coordinator, social worker, and pharmacist with reduced panel size and flexible scheduling with emphasis on motivational interviewing, patient goal setting and advanced care planning. Wait-listed participants continue usual care plus engagement with community health worker intervention for 6 months prior to joining SUMMIT. The primary outcome is hospital utilization at 6 months; secondary outcomes include emergency department utilization, patient activation, and patient experience measures. We follow participants for 12 months after intervention initiation. DISCUSSION: The SUMMIT A-ICU is an intensive primary care intervention for high-utilizers impacted by homelessness. Use of a wait-list control design balances community and staff stakeholder needs, who felt all participants should have access to the intervention, while addressing research needs to include control populations. Design limitations include prolonged follow-up period that increases risk for attrition, and conflict between practice and research; including partner stakeholders and embedded researchers familiar with the population in study planning can mitigate these barriers. Trial registration ClinicalTrials.gov NCT03224858, Registered 7/21/17 retrospectively registered https://clinicaltrials.gov/ct2/show/NCT03224858.


Asunto(s)
Enfermedad Crónica/terapia , Personas con Mala Vivienda , Aceptación de la Atención de Salud , Grupo de Atención al Paciente/organización & administración , Atención Primaria de Salud/organización & administración , Proveedores de Redes de Seguridad/organización & administración , Adulto , Planificación Anticipada de Atención/organización & administración , Anciano , Comorbilidad , Conducta Cooperativa , Femenino , Humanos , Relaciones Interinstitucionales , Masculino , Persona de Mediana Edad , Entrevista Motivacional/organización & administración , Planificación de Atención al Paciente , Satisfacción del Paciente , Proyectos de Investigación , Servicio Social/organización & administración , Factores Socioeconómicos , Servicios Urbanos de Salud
5.
Carbohydr Polym ; 181: 1206-1212, 2018 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-29253950

RESUMEN

The preparation, characterisation and application of two pyridine-modified chitosan derivatives (C1 and C2) containing Cu(OAc)2 adsorbed as catalysts for the conversion of benzaldehyde into 2-nitro-1-phenylethanol are described. Quantitative solid-state 13C multiple-contact cross-polarization, magic-angle-spinning, nuclear magnetic resonance (MC-CP MAS NMR) measurements confirmed the successful grafting of 2-pyridinecarboxaldehyde and 6-methylpyridine-2-carboxaldehyde to the chitosan backbone and indicated that 47(±2)% of the NH2 groups were grafted for both C1 and C2. The use of C1-Cu(OAc)2 as a catalyst in the nitroaldol reaction led to 96(±1)% conversion and 19(±4)% enantiomeric excess (ee), while the use of C2-Cu(OAc)2 as a catalyst also promoted the nitroaldol reaction, affording almost quantitatively the expected 2-nitro-1-phenylethanol (98(±1)%) with 14.5(±1.5)% ee.

6.
Org Lett ; 7(6): 1023-6, 2005 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-15760129

RESUMEN

[reaction: see text] Lanthanide iodo binaphtholates are efficient enantioselective catalysts for the ring opening of meso-epoxides by various aromatic amines. The study of the influence of temperature on the ring opening of cyclohexene oxide by o-anisidine catalyzed by the samarium complex shows an isoinversion effect with the maximum enantiomeric excess at -40 degrees C. Reactions of aniline, o-anisidine, or p-anisidine with five- or six-membered ring epoxides at this temperature allow the preparation of beta-amino alcohols with enantiomeric excesses up to 93%.

7.
Dalton Trans ; 44(27): 12029-59, 2015 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-25803322

RESUMEN

This Perspective article provides an overview of the recent advancements in the field of intra- and inter-molecular C-N, C-O and C-P bond formation by hydroamination, hydroalkoxylation, hydrophosphination, hydrophosphonylation or hydrophosphinylation of unactivated alkenes, including allenes, 1,3-dienes and strained alkenes, promoted by (chiral) homogeneous catalysts based on earth abundant elements of the s and p blocks, the first row transition metals and the rare-earth metals. The relevant literature from 2009 until late 2014 has been covered.


Asunto(s)
Alquenos/química , Metales/química , Catálisis
8.
Chem Commun (Camb) ; (17): 2234-5, 2003 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-13678217

RESUMEN

Charge-transfer complexes have been detected by chemical force microscopy (CFM) between a tip and a substrate respectively functionalized with trinitrofluorenone and 9-anthracenemethanol siloxane derivatives.

9.
Langmuir ; 23(2): 542-8, 2007 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-17209605

RESUMEN

Charge-transfer interaction, as a reversible and rapid phenomenon, was evidenced by force microscopy. Pull-off forces were measured between a tip grafted with a trinitrofluorenone derivative and a surface functionalized with an electron-rich aromatic anthracene compound in a dodecane environment. The effect of the sweep time on the measured interaction forces is described, together with an extensive study of a competitive influence of free aromatic molecules in dodecane diluted solutions. These forces depend on the nature of the competitor and its concentration as well as on the velocity of tip/sample separation.

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