Copper-catalyzed enantioselective allylic alkylation of azoles with γ,γ-disubstituted primary allylic phosphates was achieved using a new chiral N-heterocyclic carbene ligand bearing a naphtholic hydroxy group. This reaction occurred with excellent branch regioselectivity and high enantioselectivity, thus forming a controlled all-carbon quaternary stereogenic center at the position α to the heteroaromatic ring.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/anie.201600619 | DOI Listing |
Chem Commun (Camb)
December 2024
Instrumentation Center, National Taiwan University, Taipei, 106, Taiwan.
A visible light photocatalytic cascade reaction was developed, involving sequential self-[2+2] photodimerization of benzoylacetones, De Mayo reaction, acetalization, and alkoxylation, yielding tetrahydrofurans with high stereoselectivity, three stereogenic centers, and two quaternary carbons, under mild conditions with a cycloaddition-rearrangement strategy. Given the significance of photoreaction and rearrangement in organic chemistry, this method provides a valuable approach for the synthesis of tetrahydrofurans.
View Article and Find Full Text PDFTransition metal-catalyzed carbocyclization reactions provide a powerful method for the stereoselective assembly of complex, highly substituted (poly)cyclic scaffolds. Although 1,6-enynes are common substrates for these transformations, using polysubstituted alkene derivatives to construct functionalized cyclic products remains challenging due to their significantly lower reactivity. This highlights key developments in stereoselective semi-intramolecular metal-catalyzed [(2+2)+1] and [(2+2)+2] carbocyclizations of 1,6-enynes containing 1,1-disubstituted alkenes, which produce cycloadducts with quaternary stereogenic centers.
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 PDFChem Asian J
December 2024
IISER Bhopal: Indian Institute of Science Education and Research Bhopal, Chemistry, 462066, Bhopal, INDIA.
Natural product synthesis has been the prime focus for the development of new chemical transformations and the drug discovery. The dimeric and oligomeric hexahydropyrrolo[2,3-b]indole alkaloids represent a architecturally intriguing class of cyclotryptamine alkaloids. These alkaloids share contiguous stereogenic centers with vicinal all-carbon quaternary stereogenic centers.
View Article and Find Full Text PDFOrg Lett
December 2024
School of Chemical and Environmental Engineering and Shanghai Engineering Research Center of Green Fluoropharmaceutical Technology, Shanghai Institute of Technology, Shanghai 201418, P. R. China.
The construction of chiral tetrasubstituted α-fluoro-α-cyano carbonyl compounds remains a key challenge in synthetic organic chemistry because of their popularity in multiple disciplines. In this paper, we report the copper-catalyzed asymmetric fluorinated tertiary radical cyanation reaction of cyclic α-iodo-α-fluoroindanones with TMSCN to achieve chiral nitriles with carbon-fluorine quaternary stereogenic centers. Thus, an array of optically active tetrasubstituted monofluoroacyl nitriles were synthesized with high reaction efficiency and excellent enantioselectivities (up to 91% yield, 99% ee).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!