Herein, we describe how computational mechanistic understanding has led directly to the discovery of new 2H-phosphindole for C-C bond activation and dearomatization reaction. We uncover an unexpected intramolecular C-H bond activation with a 2H-phosphindole derivative. This new intriguing experimental observation and further theoretical studies led to an extension of the reaction mechanism with 2H-phosphindole. Through DFT calculations, we confirm that within a five-membered ring, the polarizable PC unit orchestrates the formation of an electrophilic phosphorus atom (P ) and a nucleophilic carbon atom (C ). This kinetically accessible ambiphilic phosphorus/carbon couple is spatially separated by geometric constraints, and their reactivity is modulated through structural resonance.
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http://dx.doi.org/10.1002/chem.202302889 | DOI Listing |
J Am Chem Soc
January 2025
Molecular Synthesis Center, Key Laboratory of Marine Drugs of Ministry of Education, Shandong Key Laboratory of Glycoscience and Glycotherapeutics, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
2-Deoxy-β-glycosides are essential components of natural products and pharmaceuticals; however, the corresponding 2-deoxy-β-glycosidic bonds are challenging to chemically construct. Herein, we describe an efficient catalytic protocol for synthesizing 2-deoxy-β-glycosides via either IPrAuNTf-catalyzed activation of a unique 1,2--positioned C2--propargyl xanthate (OSPX) leaving group or (PhO)PAuNTf-catalyzed activation of a 1,2--C2--alkynylbenzoate (OABz) substituent of the corresponding thioglycosides. These activation processes trigger 1,2-alkyl/arylthio-migration glycosylation, enabling the synthesis of structurally diverse 2-deoxy-β-glycosides under mild reaction conditions.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands, https://www.theochem.nl.
We have quantum chemically analyzed the trends in bond dissociation enthalpy (BDE) of H3C-XHn single bonds (XHn = CH3, NH2, OH, F, Cl, Br, I) along three different dissociation pathways at ZORA-BLYP-D3(BJ)/TZ2P: (i) homolytic dissociation into H3C∙ + ∙XHn, (ii) heterolytic dissociation into H3C+ + -XHn, and (iii) heterolytic dissociation into H3C- + +XHn. The associated BDEs for the three pathways differ not only quantitatively but, in some cases, also in terms of opposite trends along the C-X series. Based on activation strain analyses and quantitative molecular orbital theory, we explain how these differences are caused by the profoundly different electronic structures of, and thus bonding mechanisms between, the resulting fragments in the three different dissociation pathways.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Medical 3D Printing Center, Orthopedic Institute, Department of Orthopedic Surgery, The First Affiliated Hospital, School of Basic Medical Sciences, MOE Key Laboratory of Geriatric Diseases and Immunology, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, 215000, China.
Stem cell implantation holds promise for enhancing bone repair, but risks of pathogen transmission and malignant cell transformation should not be ignored. Compared to stem cell implantation, recruitment of endogenous stem cells to injured sites is more critical for in situ bone regeneration. In this study, based on the acidic microenvironment of bone injury, an HG-AA-SDF-1α composite hydrogel with a dual-control intelligent switch function is developed by incorporating stromal cell-derived factor (SDF-1α), arginine carbon dots (Arg-CDs), and calcium ions (Ca) into the oxidized hyaluronic acid/gelatin methacryloyl (HG) hydrogel.
View Article and Find Full Text PDFChemistry
January 2025
University of Sussex, Department of Chemistry, School of Life Sciences, BN1 9QJ, Brighton, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
The synthesis, structures and magnetic properties of an η5-silole complex and an η5-stannole complex of erbium are reported. The sandwich complex anions [(η5-CpSi)Er(η8-COT)]- and [(η5-CpSn)Er(η8-COT)]-, where CpSi is [SiC4-2,5-(SiMe3)2-3,4-Ph2]2- (1Si), CpSn is [SnC4-2,5-(SiMe3)2-3,4-Me2]2- (1Sn) and COT = cyclo-octatetraenyl, were obtained as their [K(2.2.
View Article and Find Full Text PDFChem Sci
January 2025
College of Chemistry and Chemical Engineering, Key (Guangdong-Hong Kong Joint) Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University Shantou 515063 P. R. China
In the past few years, the direct activation of organohalides by ligated boryl radicals has emerged as a potential synthetic tool for cross-coupling reactions. In most existing methods, ligated boryl radicals are accessed from NHC-boranes or amine-boranes. In this work, we report a new photocatalytic platform by modular assembly of readily available amines and diboron esters to access a library of ligated boryl radicals for reaction screening, thus enabling the cross-coupling of organohalides and alkenes including both activated and unactivated ones for C(sp)-C(sp) bond formation by using the assembly of DABCO A1 and BNepB1.
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