ABSTRACT
cis-Zeatin (cZ), a cytokinin often overlooked compared to trans-zeatin (tZ), can now be controlled in live cells and plants through a new biocompatible reaction. Using flavin photosensitizers, cZ can be isomerized to tZ or degraded, depending on the presence of a reducing reagent. This breakthrough offers a novel approach for regulating plant growth through chemical molecules.
Subject(s)
Flavin Mononucleotide , Zeatin , Zeatin/chemistry , Zeatin/metabolism , Flavin Mononucleotide/metabolism , Isomerism , CytokininsABSTRACT
Proteins are intriguing biomacromolecules for all living systems, not only as essential building blocks of organisms, but also as participants in almost every aspect of cellular activity such as metabolism and gene transcription/expression. Developing chemical biology tools that are capable of labeling/modifying proteins is a powerful method for decoding their detailed structures and functions. However, most current approaches heavily rely on the installation of permanent tags or genetic engineering of unnatural amino acids. There has been slow development in reversible chemical labeling using small organic probes and bioorthogonal transformations to construct site-selectively modified proteins and conditionally restore their activities or structures. This review summarizes recent advances in the field of chemical regulation of proteins with reversible transformations towards distinct motifs, including amino acid residues, amide backbones and native post-translational lysine. Finally, current challenges and future perspectives are discussed.
Subject(s)
Amino Acids , Proteins , Humans , Proteins/chemistry , Amino Acids/chemistry , Lysine/metabolism , Protein Processing, Post-TranslationalABSTRACT
A convenient Fe-catalyzed four-component radical dual difunctionalization and ordered assembly of two alkenes with aromatic/aliphatic aldehydes and TBHP to provide chain elongated ß,δ-functionalized ketones via a one-pot procedure has been developed. Aldehydes were homolytically cleavaged to produce acyl radicals and subsequently allowed for the successive construction of C(sp2)-C(sp3), C(sp3)-C(sp3), and C(sp3)-O bonds via dual radical insertions and radical-radical coupling, following the intrinsic nucleo/electrophilic reactivity of both the radicals and alkenes.
ABSTRACT
Correction for 'Fe-Catalyzed three-component carboazidation of alkenes with alkanes and trimethylsilyl azide' by Wei-Yu Li et al., Chem. Commun., 2018, DOI: .
ABSTRACT
Reported herein is a novel iron-catalyzed, DTBP-mediated carboazidation of alkenes using cycloalkanes, CH2Cl2, CHCl3 and CCl4 as alkylating reagents to generate electrophilic or nucleophilic alkyl radicals. Mechanistic studies suggested that the reaction proceeded via the addition of alkyl radicals to alkenes followed by an iron-mediated ligand transfer process. The reaction is unique as it is applicable not only to diversely functionalized electron rich alkenes, but also to electron-poor olefins to provide chain extended azides and γ-azido chloroalkanes in good to high yields.