Sarah Yunmi Lee

We describe a method for the site-selective construction of a C(aryl)-C(sp³) bond by the palladium-catalyzed direct allylation of arenes with allylic pivalates in the presence of AgOPiv to afford the linear (E)-allylated arene with excellent regioselectivity; this reaction occurs with arenes that have not undergone site-selective and stereoselective direct allylation previously, such as monofluorobenzenes and non-fluorinated arenes. Mechanistic studies indicate that AgOPiv ligated by

Substantial progress has been described in the development of asymmetric variants of the phosphine-catalyzed intermolecular [3+2] annulation of allenes with alkenes; however, there have not been corresponding advances for the intramolecular process, which can generate a higher level of complexity (an additional ring and stereocenter(s)). In this study, we describe the application of chiral phosphepine catalysts to address this challenge, thereby providing access to useful scaffolds that are foun

Because of the ubiquity of the secondary carbinol subunit, the development of new methods for its enantioselective synthesis remains an important ongoing challenge. In this report, we describe the first nonenzymatic method for the dynamic kinetic resolution (DKR) of secondary alcohols (specifically, aryl alkyl carbinols) through enantioselective acylation, and we substantially expand the scope of this approach, vis-à-vis enzymatic reactions. Simply combining an effective process for the kinetic

The catalytic asymmetric synthesis of alkyl fluorides, particularly α-fluorocarbonyl compounds, has been the focus of substantial effort in recent years. While significant progress has been described in the formation of enantioenriched secondary alkyl fluorides, advances in the generation of tertiary alkyl fluorides have been more limited. Here, we describe a method for the catalytic asymmetric coupling of aryl alkyl ketenes with commercially available N-fluorodibenzenesulfonimide (NFSI) and C6F

Despite advances in the field of asymmetric catalysis, the synthesis of complete sets of stereoisomers in multistereogenic molecules, particularly those incorporating a fluorine atom, remains a challenging task. We report, herein, a stereodivergent method for the synthesis of tertiary alkyl fluorides in vicinal stereogenic pairs through the conjugate addition of α-fluoro azaaryl acetamides to α,β-unsaturated aldehydes catalyzed by the combination of two chiral catalysts: a copper Lewis acid and

We report herein a Lewis acid-catalyzed nucleophilic double-addition of indoles to ketones under mild conditions. This process occurs with various ketones ranging from dialkyl ketones to diaryl ketones, thereby providing access to an array of bis(indolyl)methanes bearing all-carbon quaternary centers, including tetra-aryl carbon centers. The products can be transformed into bis(indole)-fused polycyclics and bis(indolyl)alkenes.

Chiral 1-pyrrolines containing a nitrile motif serve as crucial structural scaffolds in biologically active molecules and exhibit diversity as building blocks owing to their valuable functional groups; however, the asymmetric synthesis of such compounds remains largely unexplored. Herein, we present an enantio- and diastereoselective method for the synthesis of α-chiral nitrile-containing 1-pyrroline derivatives bearing vicinal stereocenters through the design and introduction of chiral cyclopro

We report herein a Lewis pair-catalyzed process for the regio- and stereoselective addition of secondary phosphine oxides (SPOs) to allenoates. A Lewis pair composed of B(C6F5)3 and P(4-OMeC6H4)3 dissociates into a free acid and base under reaction conditions, thereby creating key reaction intermediates that enable the atom-economical generation of an array of alkenylphosphorus building blocks. Mechanistic studies indicate that this process proceeds through a catalytic cycle wherein the deproton

We report the boron-catalyzed hydrophosphinylation of N-heteroaryl-substituted alkenes with secondary phosphine oxides that furnishes various phosphorus-containing N-heterocycles. This process proceeds under mild conditions and enables the introduction of a phosphorus atom into multisubstituted alkenylazaarenes. The available mechanistic data can be explained by a reaction pathway wherein the C–P bond is created by the reaction between the activated alkene (by coordination to a boron catalyst) a

Catalytic cross-couplings of tertiary alkyl electrophiles with carbon nucleophiles offer a powerful platform for constructing quaternary carbon centers, which are prevalent in bioactive molecules. However, these reactions remain underdeveloped primarily because of steric challenges that impede efficient bond formation. Herein, we describe the copper-catalyzed synthesis of such centers through the C(<i>sp</i>³)-C(<i>sp</i>²) bond-forming reaction between tertiary alkyl halid

Cu( ii ) Lewis acid/Brønsted base catalysis was employed to achieve enantio - and diastereoselective conjugate additions of pyridyl alkyl ketones to enones, resulting in the formation of various 1,5-diketones with vicinal stereocenters.

Abstract The catalytic synthesis of chiral azaarenes has become a focal point of research due to their signifi`1cant applications across various fields, including medicinal chemistry and materials science. α‐Azaaryl carbonyl compounds, featuring both an electron‐withdrawing C=N moiety within an azaarene core and a carbonyl functional group, have proven to be versatile precursors in the synthesis of stereochemically intricate azaaryl molecules. In particular, the generation of chiral α‐azaaryl en

Abstract A simple protocol employing the chiral phosphine catalysts (I) is presented for the synthesis of diquinane, fused pyrrolidine, coumarine, and quinoline derivatives.

Polylactide (PLA) is an important bioplastic derived from renewable resources, valued for its biocompatibility and biodegradability. The tacticity and microstructure of PLA significantly influence its thermomechanical properties, yet achieving both high reactivity and precise stereocontrol in the organocatalytic ring-opening polymerization of rac-lactide remains a major challenge. Herein, we show that chiral cyclopropenimine-thiourea organocatalysts enable a rapid and highly stereoselective poly

Antennas used in extreme environments, such as space, underwater, and high-temperature settings, face significant challenges in terms of durability, performance, and reliability. Traditional materials may not withstand the harsh conditions present in these environments, leading to the need for advanced materials that can provide enhanced performance and longevity. This article discusses new materials that are being developed for antennas used in extreme environments, including metamaterials, car