1,1-Bis(iodozincio)alkanes are used as dinucleophilic linchpins in an enantioselective double cross-coupling reaction sequence involving aryl iodides and then thioesters. The two catalytic C-C bond-forming reactions are achieved in the same pot through two distinct palladium-based catalytic systems: a first non-enantioselective one delivering configurationally labile secondary benzylzinc species from an achiral precursor, and a second enantioconvergent one that operates a highly efficient dynamic kinetic resolution of the racemic intermediates. This strategy, new in the area of asymmetric synthesis through two consecutive electrophilic substitution reactions of geminated C(sp )-organodimetallics, provides useful methodology to access in a modular fashion acyclic α-disubstituted ketone products with very high enantiomeric purity.
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http://dx.doi.org/10.1002/chem.202301084 | DOI Listing |
Org Lett
December 2024
School of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu 225002, China.
We present a tandem aza-Heck/Suzuki cross-coupling reaction of -phenyl hydroxamic ethers with readily available arylboronic and alkenyl boronic acids. This protocol is enabled by a palladium catalyst paired with chiral phosphoramidite ligands, particularly under mild reaction conditions, yielding efficient and succinct synthetic routes to chiral isoindolinones with high enantioselectivity. Furthermore, this reaction exhibits excellent functional group compatibility and a rich diversity of subsequent transformations.
View Article and Find Full Text PDFOrg Biomol Chem
December 2024
School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin, 300384, China.
Herein, we report an enantioselective Pd/Cu-catalyzed sequential Heck/Sonogashira coupling reaction of electron-rich enamides with terminal alkynes as substrates. This transformation proceeds smoothly to afford 3-propargyl isoindolinone derivatives bearing quaternary stereogenic centers in moderate to good yields (43-77% yield) and good to excellent enantioselectivity (up to 93% ee). Functional groups such as halogen atoms (F, Cl, and Br), thienyl, and silyl moieties are tolerated well.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
State key laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin, 541004, China.
Skeletal editing represents an attractive strategy for adding complexity to a given molecular scaffold in chemical synthesis. Isodesmic reactions provide a complementary skeletal editing approach for the redistribution of chemical bonds in chemical synthesis. However, catalytic enantioselective isodesmic reaction is extremely scarce and enantioselective isodesmic reaction to synthesize atropisomeric compounds is unknown.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Department of Chemistry, Fudan University, 220 Handan Rd., Shanghai, 200433, China.
Atropisomers with multiple stereogenic axes have attracted much attention due to their increasing significance in the fields of natural products, chiral materials, and drug discoveries. However, the catalytic stereoselective construction of axially chiral ring scaffolds with more than two axes on a single benzene ring remains a challenging task. Herein, we present an efficient method for synthesizing triaxially chiral polysubstituted naphthalene scaffolds via sequential Ni(II)-catalyzed Diels-Alder reaction of isobenzofurans and TfOH-promoted dehydrative aromatization reaction.
View Article and Find Full Text PDFOrg Lett
December 2024
Department of Chemistry, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal Bypass Road, Bhauri, Bhopal, Madhya Pradesh 462 066, India.
We envisioned a novel asymmetric strategy to access unsymmetrically substituted dimeric 2-oxindoles [(,)- and (,)-] for the total synthesis of calycanthidine (). The key to success is the development of efficient Pd(0)-catalyzed asymmetric sequential allylations [via a highly enantioselective [up to 94% enantiomeric excess (ee)] and diastereoselective (up to ∼13:1) process] of unsymmetrically protected dimeric 2-oxindoles at the 3,3' position [such as (,)- and (,)-]. Gratifyingly, a mixture of bis-ester (±)-, ester-carbonates (±)- and (±)-, and bis-carbonate could afford (,)- and (,)- in highly stereoselective fashion, thereby culminating in the total synthesis of (+)-calycanthidine [-()] and (-)-calycanthidine ().
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