The use of a non-coordinating solvent for the aza-Claisen rearrangement of delta,epsilon-disubstituted acetimidates switches on a substrate directing effect that gives excellent stereoselectivity.

Download full-text PDF

Source
http://dx.doi.org/10.1039/b613271eDOI Listing

Publication Analysis

Top Keywords

stereocontrol palladiumii-catalysed
4
palladiumii-catalysed aza-claisen
4
aza-claisen rearrangements
4
rearrangements combination
4
combination 13-allylic
4
13-allylic strain
4
strain solvent
4
solvent mediated
4
mediated directing
4
directing non-coordinating
4

Similar Publications

Stereocontrolled construction of tetrasubstituted olefins has been an attractive issue yet remains challenging for synthetic chemists. In this manuscript, alkynyl selenides, when treated with ArBCl, are subject to an exclusive 1,1-carboboration, affording tetrasubstituted alkenes with excellent levels of E-selectivity. Detailed mechanistic studies, supported by DFT calculations, elucidates the role of selenium in this 1,1-addition process.

View Article and Find Full Text PDF

Chiral medium-sized rings, albeit displaying attractive properties for drug development, suffer from numerous synthetic challenges due to difficult cyclization steps that must take place to form these unusually strained, atropisomeric rings from sterically crowded precursors. In fact, catalytic enantioselective cyclization methods for the formation of chiral seven-membered rings are unknown, and the corresponding eight-membered variants are also sparse. In this work, we present a substrate preorganization-based, enantioselective, organocatalytic strategy to construct seven- and eight-membered rings featuring chirality that is intrinsic to the ring in the absence of singular stereogenic atoms or single bond axes of chirality.

View Article and Find Full Text PDF

Our efforts toward the synthesis of the marine natural product portimine are described. The key to the synthesis of the skeleton is a stereoretentive copper-catalyzed C()-C() Stille-type cross-coupling that enables the convergent assembly of functionalized fragments. The core skeleton of portimine was constructed via ring-closing metathesis and transannular acetal formation.

View Article and Find Full Text PDF

Reactivity of Anomalous Aziridines for Versatile Access to High Fsp Amine Chemical Space.

Acc Chem Res

January 2025

Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States.

ConspectusThe manipulation of strained rings is a powerful strategy for accessing the valuable chemical frameworks present in natural products and active pharmaceutical ingredients. Aziridines, the smallest N-containing heterocycles, have long served as building blocks for constructing more complex amine-containing scaffolds. Traditionally, the reactivity of typical aziridines has been focused on ring-opening by nucleophiles or the formation of 1,3-dipoles.

View Article and Find Full Text PDF

Poly(lactic-co-glycolic acid) (PLGA) has been widely employed for various biomedical applications owing to its biodegradability and biocompatibility. The discovery of the stereocomplex formation between enantiomeric alternating PLGA pairs underscored its potential as high-performance biodegradable materials with diverse material properties and biodegradability. Herein, we have established a regio- and stereoselective ring-opening polymerization approach for the synthesis of stereocomplexed isoenriched alternating PLGA from racemic methyl-glycolide (rac-MG).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!