Herein, we report ag eneral iminium ion-based catalytic method for the enantioselective conjugate addition of carbon-centered radicals to aliphatic and aromatic enals.T he process uses an organic photoredox catalyst, whicha bsorbs blue light to generate radicals from stable precursors,i n combination with ac hiral amine catalyst, which secures ac onsistently high level of stereoselectivity.T he generality of this catalytic platform is demonstrated by the stereoselective interception of aw ide variety of radicals,i ncluding nonstabilized primary ones whichare generally difficult to engage in asymmetric processes.T he system also served to develop organocatalytic cascade reactions that combine an iminiumion-based radical trap with an enamine-mediated step,affording stereochemically dense chiral products in one-step.

In this work, we exploit our strategy of in situ secondary-sphere modification of organocatalysts to improve the reactivity and selectivity of amino catalysts. Herein, the carboxylic acid moiety of proline...

The chemical sciences are witnessing an influx of statistics into the catalysis literature. These developments are propelled by modern technological advancements that are leading to fast and reliable data production, mining, and management. In organic chemistry, models encoded with information-rich parameters have facilitated the formulation of mechanistic hypotheses across different data-size regimes. Herein, we aim to demonstrate through selected examples that the integration of statistical principles into homogeneous catalysis can streamline not only reaction optimization protocols but also mechanistic investigation procedures. Namely, we highlight how different aspects of molecular modeling, data set design, data visualization, and nuanced data restructuring can contribute to improving chemical reactivity and selectivity, while furthering our understanding of reaction mechanisms. By mapping out these techniques at different data set sizes, we hope to encourage the broad application of data-driven approaches for mechanistic studies regardless of the accessible amount of data.

A new and facile one-pot synthesis of 1,3-disubstituted allenes, using cheap and readily available terminal alkynes, benzaldehyde derivatives and morpholine, was developed. A small library of 20 allenes demonstrates a broad applicability, with yields up to 86%. Isotopic-labelling and cross-over experiments strongly indicate that our reaction proceeds via a two-step A 3 -coupling followed by a 1,5-hydrogen shift process.

The critical influence of solvent effects on proline-catalyzed aldol reactions has been extensively described. Herein, we apply multivariate regression strategies to probe the influence of different solvents on an aldol reaction catalyzed by proline modified at its secondary sphere with boronic acids. In this system, both in situ binding of the boronic acid to proline and the outcome of the aldol reaction are impacted by the solvent-controlled microenvironment. Thus, with the aim of uncovering mechanistic insight and an ancillary aim of identifying methodological improvements, we designed a set of experiments, spanning 15 boronic acids in five different solvents. Based on hypothesized intermediates or interactions that could be responsible for the selectivity in these reactions, we proposed several structural configurations for the library of boronic acids. Subsequently, we compared the statistical models correlating the outcome of the reaction in different solvents with molecular descriptors produced for each of these proposed configurations. The models allude to the importance of different interactions in controlling selectivity in each of the studied solvents. As a proof-of-concept for the practicality of our approach, the models in chloroform ultimately led to lowering the ketone loading to only two equivalents while retaining excellent yield and enantio- and diastereo-selectivity.

The reactivity of cationic (C^C)gold(III) carbonyl complexes was investigated. While the in situ-formed IPrAu(bph)CO+ complex (bph = biphenyl-2,2’-diyl) does not undergo a migratory insertion of CO into the neighboring gold-carbon...

Gold-catalyzed cyclization of 1,5-diynesw ith ketones as reagents and solvent provides diversely substituted vinyl ethers under mild conditions. The regioselectivity of such gold-catalyzed cyclizations is usually controlled by the scaffold of the diyne. Herein, we report the first solvent-controlled switchingo fr egioselectivity from a6 -endo-dig-to 5endo-dig-cyclization in these transformations,p roviding fulvene derivatives. With respectt ot he functional-group toler-ance, aryl fluorides, chlorides, bromides,and ethers are tolerated. Furthermore, the mechanism and selectivity are put to scrutinyb ye xperimental studies and at hermodynamic analysis of the product. Additionally,6 -(vinyloxy)fulvenesa re a hitherto unknown class of compounds. Theirr eactivity is briefly evaluated, to give insights into their potential applications.[ + + ] Crystallographic investigation;T heoreticali nvestigation Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

An unprecedented, often almost quantitative access to tricyclic aromatic compounds by dual gold catalysis was developed. This synthetic route expands the scope of benzofulvene derivatives through a C(sp )-H bond insertion in easily available starting materials. The insertion takes place with an exclusive chemoselectivity with respect to the competing aromatic C-H positions. A bidirectional synthesis with two competing ortho-aryl C-H bonds in the selectivity-determining step also shows perfect selectivity; this result is explained by a computational investigation of the two conceivable intermediates. The intramolecular competition of two non-equivalent aryl C-H bonds with a benzylic methyl group also showed perfect selectivity.