A simple and efficient asymmetric synthesis of novel sp -rich pyrrolidine chemical scaffolds over five steps starting from simple ketones is described. Key steps involve the use of tert-butanesulfinamide as a chiral auxiliary to perform an asymmetric Tsuji-Trost allylation, with subsequent cross-metathesis with an acrylate ester and reduction of the sulfinimine/cyclisation of the resulting amine giving the pyrrolidine scaffolds in high yields and diastereoselectivites. By removing the chiral auxiliary and functionalising the ester group, the resulting scaffold core can be further derivatised.
Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, China.
A palladium-catalyzed asymmetric chlorocyclization of 1,6-enynes has been described. Controlling the chloride ion concentration in the system by substrate design is the key to achieving asymmetric chlorinated cyclization. In the presence of Pd(PhCN)Cl and chiral phosphoramidite ligands, the reaction accesses diverse chiral ()-α-chloromethylene-γ-butyrolactams with excellent selectivity and enantioselectivity.
School of Chemistry and Chemical Engineering/State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, Shihezi University, Shihezi, Xinjiang 832003, China.
Easily obtainable and efficient chiral -symmetric bipyridine-,'-dioxide ligands with Ni(OTf) were developed for application in catalyzing [3 + 2] cycloaddition reactions to synthesize optically active fused pyrazolidines or pyrazoline derivatives featuring three contiguous stereogenic centers by employing azomethine imines and α,β-unsaturated 2-acyl imidazoles, affording the corresponding adducts with the opposite configuration compared to previous synthetic products in 80-98% yields with 28-99% ee and >20:1 dr. In addition, subsequent amplification experiments and derivative transformations of the product further demonstrated the efficient catalytic performance of the catalyst Ni(II)-bipyridine-,'-dioxide complexes and the practicality of this synthesis methodology.
Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa-ku, Nagoya 466-8555, Japan.
Herein, we present the enantioselective synthesis of 2,3-dihydro-4-quinolones bearing chiral tetrasubstituted carbons from isatins and 2'-aminoacetophenones. The transformation is mediated by a chiral phosphoric acid catalyst and proceeds via an generated ketimine and subsequent enantioselective intramolecular cyclization. The methodology features a broad scope and functional group tolerance with yields and enantioselectivities of up to 99% and 98% ee.
Living microorganisms can perform directed migration for foraging in response to a chemoattractant gradient. We report a biomimetic strategy that rotary FF-ATPase (adenosine triphosphatase)-propelled flasklike colloidal motors exhibit positive chemotaxis resembling the chemotactic behavior of bacteria. The streamlined flasklike colloidal particles are fabricated through polymerization, expansion, surface rupture, and re-polymerizing nanoemulsions composed of triblock copolymers and ribose.
The production of enantiomerically pure compounds remains a vital and valuable objective in modern organic chemistry due to their broad applications in fields such as biosensing, optics, electronics, photonics, catalysis, nanotechnology, and drug or DNA delivery. Optically pure α-hydroxy ketones, in particular, are key structural components in many drugs and natural products with significant biological activity. Among these, benzoin type α-hydroxy ketones, which possess two adjacent functional groups, a carbonyl and a hydroxy group, are especially important.
