CAFETALES DE CUBA [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

C(sp3)–H Functionalization by Allylic C–H Activation of Zirconocene Complexes

International audienc

C(sp3)–H Functionalization by Allylic C–H Activation of Zirconocene Complexes

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Alkene-Zipper Catalyzed Selective and Remote Retro-ene Reaction of Alkenyl Cyclopropylcarbinol

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Remote functionalization through alkene isomerization

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A unique Pd-catalysed Heck arylation as a remote trigger for cyclopropane selective ring-opening

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Formamides as Isocyanate Surrogates: A Mechanistically Driven Approach to the Development of Atom-Efficient, Selective Catalytic Syntheses of Ureas, Carbamates, and Heterocycles

International audienceDespite the hazardous nature of isocyanates, they remain key building blocks in bulk and fine chemical synthesis. By surrogating them with less potent and readily available formamide precursors, we herein demonstrate an alternative, mechanistic approach to selectively access a broad range of ureas, carbamates and heterocycles via a ruthenium-based pincer complex catalyzed acceptorless dehydrogenative coupling reactions. The design of these highly atom-efficient procedures was driven by the identification and characterization of the relevant organometallic complexes, uniquely exhibiting the trapping of an isocyanate intermediate. DFT calculations further contributed to shed light on the remarkably orchestrated chain of catalytic events, involving metal-ligand cooperation

Zirconocene-Mediated Selective C–C Bond Cleavage of Strained Carbocycles: Scope and Mechanism

International audienceSeveral approaches using organozirconocene species for the remote cleavage of strained three-membered ring carbocycles are described. ω-Ene polysubstituted cyclopropanes, alkylidenecyclopropanes, ω-ene spiro[2.2]pentanes, and ω-ene cyclopropyl methyl ethers were successfully transformed into stereodefined organometallic intermediates, allowing an easy access to highly stereoenriched acyclic scaffolds in good yields and, in most cases, excellent selectivities. DFT calculations and isotopic labeling experiments were performed to delineate the origin of the obtained chemo- and stereoselectivities, demonstrating the importance of microreversibility

Zirconocene-Mediated Selective C–C Bond Cleavage of Strained Carbocycles: Scope and Mechanism

Several approaches using organozirconocene species for the remote cleavage of strained three-membered ring carbocycles are described. ω-Ene polysubstituted cyclopropanes, alkylidenecyclopropanes, ω-ene spiro[2.2]­pentanes, and ω-ene cyclopropyl methyl ethers were successfully transformed into stereodefined organometallic intermediates, allowing an easy access to highly stereoenriched acyclic scaffolds in good yields and, in most cases, excellent selectivities. DFT calculations and isotopic labeling experiments were performed to delineate the origin of the obtained chemo- and stereoselectivities, demonstrating the importance of microreversibility

Shared heritability of human face and brain shape.

Evidence from model organisms and clinical genetics suggests coordination between the developing brain and face, but the role of this link in common genetic variation remains unknown. We performed a multivariate genome-wide association study of cortical surface morphology in 19,644 individuals of European ancestry, identifying 472 genomic loci influencing brain shape, of which 76 are also linked to face shape. Shared loci include transcription factors involved in craniofacial development, as well as members of signaling pathways implicated in brain–face cross-talk. Brain shape heritability is equivalently enriched near regulatory regions active in either forebrain organoids or facial progenitors. However, we do not detect significant overlap between shared brain–face genome-wide association study signals and variants affecting behavioral–cognitive traits. These results suggest that early in embryogenesis, the face and brain mutually shape each other through both structural effects and paracrine signaling, but this interplay may not impact later brain development associated with cognitive function