Organic superbases are a distinct and increasingly utilized class of Bronsted base that possess properties complementary to common inorganic bases. This Concept article discusses recent applications of commercial organic superbases in modern synthetic methodologies. Examples of the advantages of organic superbases in three areas are highlighted, including the discovery of new base-catalyzed reactions, the optimization of reactions that require stoichiometric Bronsted base, and in high-throughput experimentation technology.

Organic Superbases in Recent Synthetic Methodology Research.

The chemistry and biology of guanidine secondary metabolites.

Lead halide perovskite nanocrystals were prepared and used as photocatalysts for the in situ 1O2 generation to perform hetero Diels–Alder, ene and oxidation reactions with suitable dienes and alkenes. The methodology has been reasonably standardized and made applicable to a variety of olefinic substrates. The scope of the method is finely illustrated by the results in all the tested reactions, which allowed to obtain desymmetrized hydroxy-ketone derivatives, unsaturated ketones and epoxides. Some limitations were also observed especially in the case of the alkene oxidations as well as poor chemoselectivity was somewhere observed. 1O2 generated by lead halide perovskite nanocrystals as photocatalyst in organic reactions.

/pdf/nanocrystals-perovskites-photocatalyzed-singlet-oxygen-21hy6e4izi.pdf

Nanocrystals perovskites photocatalyzed singlet oxygen generation for light-driven organic reactions

g-C3N4/metal halide perovskite composites as photocatalysts for singlet oxygen generation processes for the preparation of various oxidized synthons

Using a visible-light photoredox catalysis strategy with household decorative blue LEDs and the additives Et3N and DIPEA, as well as the subsequent hydrolysis sequence, a mild one-pot process for the direct transformation of nitroalkanes to the corresponding ketones and aldehydes, constituting a Nef-like reaction, has been developed. It is worth noting that by using an appropriate photocatalyst (e.g., [Ir(dtbbpy)(ppy)2]PF6) and the extra additive Et3N with the combination of DIPEA and Mg(ClO4)2 in i-PrOH (instead of CH3CN), the transformation of nitroalkanes to the corresponding oximes, rather than nitrones, can be markedly more effective. The oximes can then be hydrolyzed to ketones by reaction with CuCl2·2H2O in a pH 7 buffer solution. This process is appealing because of the benefits of efficient conversion, mild conditions, high yields, and general applicability to compounds with a wide range of labile functional groups.

A mild one-pot transformation of nitroalkanes to ketones or aldehydes via a visible-light photocatalysis-hydrolysis sequence.

Sequential Reduction of Nitroalkanes Mediated by CS2 and Amidine/Guanidine Bases: A Controllable Nef Reaction

Silanes are important compounds in industrial and synthetic chemistry. Here, we develop a general approach for the synthesis of disilanes as well as linear and cyclic oligosilanes via the reductive activation of readily available chlorosilanes. The efficient and selective generation of silyl anion intermediates, which are arduous to achieve by other means, allows for the synthesis of various novel oligosilanes by heterocoupling. In particular, this work presents a modular synthesis for a variety of functionalized cyclosilanes, which may give rise to materials with distinct properties from linear silanes but remain challenging synthetic targets. In comparison to the traditional Wurtz coupling, our method features milder conditions and improved chemoselectivity, broadening the functional groups that are compatible in oligosilane preparation. Computational studies support a mechanism whereby differential activation of sterically and electronically distinct chlorosilanes are achieved in an electrochemically driven radical-polar crossover mechanism.

An Electrochemical Strategy to Synthesize Disilanes and Oligosilanes from Chlorosilanes.

ADVERTISEMENT RETURN TO ARTICLES ASAPPREVViewpointNEXTDeep Electroreductive Chemistry: Harnessing Carbon- and Silicon-Based Reactive Intermediates in Organic SynthesisWen ZhangWen ZhangDepartment of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United StatesMore by Wen Zhanghttps://orcid.org/0000-0002-0704-3463, Weiyang GuanWeiyang GuanDepartment of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United StatesMore by Weiyang Guan, Jesus I. Martinez AlvaradoJesus I. Martinez AlvaradoDepartment of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United StatesMore by Jesus I. Martinez Alvarado, Luiz F. T. NovaesLuiz F. T. NovaesDepartment of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United StatesMore by Luiz F. T. Novaeshttps://orcid.org/0000-0003-1209-2865, and Song Lin*Song LinDepartment of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States*Email: [email protected]More by Song Linhttps://orcid.org/0000-0002-8880-6476Cite this: ACS Catal. 2023, 13, XXX, 8038–8048Publication Date (Web):May 31, 2023Publication History Received14 March 2023Published online31 May 2023https://doi.org/10.1021/acscatal.3c01174© 2023 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views-Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-Alerts Get e-Alerts 

https://pubs.acs.org/doi/pdf/10.1021/acscatal.3c01174

Weiyang Guan

Papers

Sequential Reduction of Nitroalkanes Mediated by CS2 and Amidine/Guanidine Bases: A Controllable Nef Reaction

An Electrochemical Strategy to Synthesize Disilanes and Oligosilanes from Chlorosilanes.

Deep Electroreductive Chemistry: Harnessing Carbon- and Silicon-Based Reactive Intermediates in Organic Synthesis