State Key Laboratory of Chirosciences and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.
Published: February 2012
AI Article Synopsis
Article Abstract
An efficient modular approach for single-site incorporation of two independent functionalities (amines and alkynes) into aldehyde-containing oligosaccharides concurrently by using a one-pot gold-mediated three-component coupling reaction in aqueous medium under mild conditions has been developed.
A regioselective cobalt-catalyzed three-component silylamidation that rapidly and reliably incorporates dioxazolones and silylzinc pivalates into unconjugated alkenyl amides is disclosed. Notably, the unique power of this protocol is demonstrated by the possibility of achieving peptide ligation using peptide-containing dioxazolones or alkenyl amides as the coupling partners. Moreover, this approach is distinguished by its mild condition, synthetic simplicity, and ample scope, thus providing a new platform for modular access to silicon-containing amino acid derivatives and peptides.
Herein, we describe a sustainable Co(II)-catalyzed synthesis of pyrroles and pyridines. Using a Co(II)-catalyst [CoII2(La)2Cl2] (1a) bearing redox-active 2-(phenyldiazenyl)-1,10-phenanthroline) (La) scaffold, various substituted pyrroles and pyridines were synthesized in good yields, taking alcohol as one of the primary feedstock. Pyrroles were synthesized by the equimolar reaction of 2-amino and secondary alcohols.
An efficient and facile method has been developed for the construction of novel P-S-C and P-Se-C bonds by facilitating the three-component cross-coupling reaction of P-H bonds with elemental sulfur/selenium and vinylsulfonium salts, utilizing sodium bicarbonate as a base. This approach eliminates the need for the use of toxic and odorous active sulfur/selenium reagents and noble metals, thereby offering a new pathway for synthesizing -phosphinothioates and -phosphinoselenoates via the organic conversion of inorganic sources. The reaction has showcased remarkable versatility in terms of substrate applicability, particularly for organophosphorus compounds containing P-H bonds and vinylsulfonium salt derivatives.
Herein, we unveiled a regio- and diastereoselective synthesis of cyclobutylated phenothiazines, a unique class of structural congeners of phenothiazines visible-light-irradiated intermolecular [2 + 2]-cycloaddition reaction, from readily available naphthoquinones, 2-aminothiophenols, and styrenes, either in a two-step or three-component coupling process. By varying substitutions in all three coupling partners, a library of cyclobutylated phenothiazines, including late-stage derivatization with five commercial drugs, has been realized with up to 97% isolated yield. In contrast to the reported pathways, the developed [2 + 2]-photocycloaddition seems to proceed a 'photoinduced-electron-transfer' (PET) mechanism, which is well corroborated with the experimental observations, Rehm-Weller equation, and computation studies.
A novel three-component radical cyclization/haloazidation of enynones, employing TMSN as the azide source and NIS (NBS or NCS) as the halogen source, has been developed under metal-free conditions for the efficient synthesis of various 1-indanones with moderate yields and acceptable / ratio. The reaction progresses through a sequence involving radical addition, 5- cyclization, and radical coupling, ultimately resulting in the formation of three new chemical bonds and a new ring in a single step. The synthetic benefits of this method have been proven by large-scale experiments and late-stage modification.
