Abstract The spiro[pyrrolidine‐3,3′‐oxindole] ring system is found at the core of a number alkaloids, which possess significant biological activity and are interesting, challenging targets for chemical synthesis. In present review, we report on different strategies synthesis in context recent coerulescine, horsfiline, elacomine, salacin, pteropodine, alstonisine, spirotryprostatin A B, strychnofoline. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirected reduction of .beta.-hydroxy ketones employing tetramethylammonium triacetoxyborohydrideD. A. Evans, K. T. Chapman, and E. M. CarreiraCite this: J. Am. Chem. Soc. 1988, 110, 11, 3560–3578Publication Date (Print):May 1, 1988Publication History Published online1 May 2002Published inissue 1 1988https://pubs.acs.org/doi/10.1021/ja00219a035https://doi.org/10.1021/ja00219a035research-articleACS PublicationsRequest reuse permissionsArticle...

An important challenge in asymmetric synthesis is the development of fully stereodivergent strategies to access full complement stereoisomers products bearing multiple stereocenters. In ideal case, where four are possible, applying distinct catalysts same set starting materials under identical conditions would a single step afford any given stereoisomer. Herein, we describe realization this concept dual-catalytic γ,δ-unsaturated aldehydes vicinal quaternary/tertiary stereogenic centers. The...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTFacile Enantioselective Synthesis of Propargylic Alcohols by Direct Addition Terminal Alkynes to AldehydesDoug E. Frantz, Roger Fässler, and Erick M. CarreiraView Author Information Laboratorium für Organische Chemie ETH-Zürich, Universitätstrasse 16 CH-8092 Zürich, Switzerland Cite this: J. Am. Chem. Soc. 2000, 122, 8, 1806–1807Publication Date (Web):February 9, 2000Publication History Received28 October 1999Published online9 February...

Metal-catalyzed asymmetric processes offer one of the most straightforward ways to introduce stereogenic centers. Hence, development novel chiral ligands that can effectively induce asymmetry in reactions is crucial modern organic synthesis. While many established bind a metal through heteroatoms, structures coordinate metals carbon atoms have received little attention so far. Here, we highlight increasing number such chelating olefin as well their application variety metal-catalyzed transformations.

This Minireview highlights recent advances in the field of aryne and cyclohexyne chemistry that have allowed extraordinary reactivity these entities to be harnessed during course natural product syntheses. The syntheses presented rely on use reactive species chemoselective transformations follow unprecedented synthetic strategies are inspiring for practitioners organic chemistry.

We report an Ir(I)-catalyzed kinetic resolution of secondary allylic carbonates allowing for their isolation in up to 98% ee. Importantly, the study documents synthesis and use a new class chiral [2.2.2]-bicyclooctadiene ligands iridium.

This Perspective presents an overview of catalytic enantioselective transformations that allow convenient access to all stereoisomers a given product with multiple stereogenic centers. Particular focus is placed on discussion the concept stereodivergent dual catalysis and its application in target-oriented synthesis. The potential this development new as well implications for achieving stereochemical diversity library design diversity-oriented synthesis are also discussed.

We describe the fully stereodivergent, dual catalytic α-allylation of linear aldehydes. The reaction proceeds via direct iridium-catalyzed substitution racemic allylic alcohols with enamines generated in situ. use an Ir(P,olefin) complex and a diarylsilyl prolinol ether as catalysts presence dimethylhydrogen phosphate promoter proved to be crucial for achieving high enantio- diastereoselectivity (>99% ee, up >20:1 dr). utility method is demonstrated concise enantioselective synthesis...

An oxetane can trigger profound changes in aqueous solubility, lipophilicity, metabolic stability, and conformational preference when replacing commonly employed functionalities such as gem-dimethyl or carbonyl groups. The magnitude of these depends on the structural context. Thus, by substitution a group with an oxetane, solubility may increase factor 4 to more than 4000 while reducing rate degradation most cases. incorporation into aliphatic chain cause favoring synclinal rather antiplanar...

A short and modular synthesis of novel P,N ligands (pinap; see scheme; X=O or NH) is presented. covalently bound chiral group allows the separation atropisomeric diastereomers, thus avoiding resolution involving Pd–amine complexes. The utility demonstrated for three reactions catalyzed by different transition metals; in each case products are obtained with high enantiomeric excess (up to 99 % ee).

The discovery, study, and implementation of the Co- Mn-catalyzed hydrohydrazination hydroazidation reactions olefins are reported. These equivalent to direct hydroaminations C-C double bonds with protected hydrazines or hydrazoic acid but based on a different concept in which H N atoms come from two reagents, silane an oxidizing nitrogen source (azodicarboxylate sulfonyl azide). reaction using di-tert-butyl azodicarboxylate is characterized by its ease use, large functional group tolerance,...

ConspectusThe catalytic, asymmetric synthesis of complex molecules has been a core focus our research program for some time because developments in the area can have an immediate impact on identification novel strategies value-added molecules. In concert with this central interest, we emphasized design ligand scaffolds as tactic to discover and develop chemistry overcome well-recognized synthetic challenges. Based group's work chiral pool-derived diolefin ligands, designed implemented class...

The first example of Ir-catalyzed asymmetric substitution reaction with vinyl trifluoroborates is described. direct between branched, racemic allylic alcohols and potassium alkenyltrifluoroborates proceeded high site selectivity excellent enantioselectivity (up to 99%) mediated by an Ir-(P,olefin) complex. This method allows rapid access various 1,4-dienes or trienes including the biologically active natural products (-)-nyasol (-)-hinokiresinol.

Completing the cycle: Cobalt complexes I and II were found to catalyze intramolecular alkyl Heck-type coupling reactions of iodides alkenes upon irradiation with visible light in presence a tertiary amine base. The use base is key catalytic turnover. compatibility method broad range functional groups opens opportunities for synthesis.

Off-tissue effects are persistent issues of modern inhibition-based therapies. By merging the strategies photopharmacology and small-molecule degraders, we introduce a novel concept for spatiotemporal control induced protein degradation that potentially prevents off-tissue toxicity. Building on successful principle bifunctional all-small-molecule Proteolysis Targeting Chimeras (PROTACs), designed photoswitchable PROTACs (

Abstract Fully stereodivergent dual‐catalytic α‐allylation of protected α‐amino‐ and α‐hydroxyacetaldehydes is achieved through iridium‐ amine‐catalyzed substitution racemic allylic alcohols with chiral enamines generated in situ. The operationally simple method furnishes useful aldehyde building blocks good yields, more than 99 % ee , d.r. values greater 20:1 some cases. Additionally, the γ,δ‐unsaturated products can be further functionalized a fashion high selectivity preservation...

A highly enantioselective polycyclization method has been developed using the combination of Lewis acid activation with iridium-catalyzed allylic substitution. This strategy relies on direct use branched, racemic alcohols and furnishes a diverse unique set carbo- heteropolycyclic ring systems in good yields ≥99% ee.