Article
Chemistry, Organic
Lan Bao, Min Li, Lianshun Zhang, Yating Xue, Jinhuan Dong, Xianxiu Xu
Summary: We report a new isocyanide-based three-component reaction that generates an unprecedented zwitterionic intermediate from the chemoselective heterodimerization of weak electrophilic ortho-diisocyanoarenes and common isocyanides. This reactive zwitterion can react in situ with various trapping agents to form a range of structurally diverse quinoxalines.
Article
Chemistry, Organic
Anu Jacob, Philip Barkawitz, Peter G. Jones, Daniel B. Werz
Summary: A facile and efficient route to dithiolanes starting from donor-acceptor cyclopropanes has been developed. Potassium p-toluenethiosulfonate has been established as the optimal reagent for this reaction. The methodology allows for the synthesis of dithiolanes in moderate to good yields with high functional group tolerance.
Article
Chemistry, Multidisciplinary
Avishek Guin, Subrata Bhattacharjee, Akkattu T. Biju
Summary: This study demonstrates the direct C2-functionalization of pyridines through a transition-metal-free protocol using aryne multicomponent coupling. The reaction allows for the synthesis of C2-substituted pyridine derivatives bearing the -CF3 group in good yields, with activated keto esters also being employed as third components in the formal 1,2-di(hetero)arylation of ketones. Performing the reaction under dilute conditions inhibits the competing pyridine-aryne polymerization pathway, leading to the desired products.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Lan Bao, Yu Liu, Jinghan Peng, Yuan Wang, Jinhuan Dong, Xianxiu Xu
Summary: The catalyst-free chemoselective trimerization reaction of isocyanides leads to the formation of a wide range of 2-(indol-2-yl)-quinolines and 2-(indol-2-yl)-pyridines in moderate to excellent yields. The key step of this reaction is proposed to be the head to head heterodimerization of two isocyanides.
Article
Chemistry, Organic
Jackson A. Gartman, Uttam K. Tambar
Summary: The scientific community has shown great interest in anthraquinone-based compounds due to their therapeutic properties and challenging structural elements. In recent decades, various architecturally beautiful natural products have been synthesized using two main strategies, either through early-stage synthesis of anthraquinone and further system elongation, or late-stage introduction of the anthraquinone ring moiety. This article describes selected syntheses of complex anthraquinone monomers and dimers from the past 20 years, with a focus on the retrosynthetic disconnections that shape the anthraquinone-installation strategy.
Article
Chemistry, Organic
Baihui Zheng, Xiaotong Li, Yang Song, Shuyang Meng, Yifei Li, Qun Liu, Ling Pan
Summary: A visible-light-induced [3+2] oxidative cyclization of alkynes with ketene dithioacetals in the presence of an acridine photosensitizer was reported, leading to regioselective synthesis of multisubstituted thiophenes in high yields under metal-free conditions. This reaction showed good substrate tolerance and efficiency in large-scale syntheses. The reaction mechanism and applications were detailed to illustrate the reactivity of the new 1,3-dipoles and the selectivity of the reactions.
Article
Chemistry, Organic
Anu Jacob, Peter G. G. Jones, Daniel B. B. Werz
Summary: A new method for synthesizing tetrahydroselenophenes with exocyclic double bonds was reported, which involves the reaction of donor-acceptor cyclopropanes (DACs) with lithium alkynylselenolates in the presence of In(OTf)3. The method has a broad substrate scope and high yields.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Applied
Lu Wang, Yi-Ting Shen, Yu-Xin Wang, Hai-Ying Wang, Wen-Juan Hao, Bo Jiang
Summary: A metal-free radical multicomponent bicyclization of heteroatom-linked 1,7-diynes with aryl diazonium tetrafluoroborates and DABCO-bis(sulfurdioxide) (DABSO) is reported, enabling the production of two types of skeletally diverse tricyclic sulfones, namely, thieno[3,4-c]quinoline 2,2-dioxides and thieno[3,4-c]chromene 2,2-dioxides, with moderate to good yields by simply tuning the linkers of the 1,7-diynes. This protocol demonstrates remarkable compatibility regarding N- and O-linked 1,7-diynes with different substitution patterns and aryl diazonium tetrafluoroborates.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Applied
Hao Yuan, Dong-Liu Lu, Cui Liang, Dong-Liang Mo
Summary: Various spirooxindole-benzo[d]oxazoles and dihydrobenzofurans were successfully synthesized via transition metal-free [3 + 2] cycloaddition and selective rearrangement. The substituent on the N-vinyl group of the nitrone was found to control the [1,3]- or [3,3]-rearrangement of the cycloadduct due to steric effects. This method demonstrates broad substrate scope, good functional group tolerance, controllable rearrangement, and diverse oxindole scaffolds.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Yue-You Chen, Chen-Dong Zhou, Xing-Tong Li, Ting-You Yang, Wen-Yong Han, Nan-Wei Wan, Yong-Zheng Chen, Bao-Dong Cui
Summary: A cooperative tertiary amine/palladium-catalyzed sequential reaction process has been developed for the synthesis of spiro[methylene cyclopentane-1,3 '-oxindo-lines]. This process involves a [4 + 3] cyclization of isatin-derived Morita-Baylis-Hillman Expansion (MBH) carbonates and tert-butyl 2-(hydroxymethyl)allyl carbonates, followed by a [1,3]-rearrangement. The synthetic compounds obtained exhibit excellent regio- and stereocontrol, and this protocol has potential for large-scale synthesis and diverse functional transformations.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Yu Zhang, Yanchuan Li, Shao-Fei Ni, Jin-Peng Li, Dingding Xia, Xinyu Han, Jingchuan Lin, Jinxin Wang, Shoubhik Das, Wei-Dong Zhang
Summary: Visible-light-induced [3+2] cycloadditions of donor/donor diazo precursors with alkenes to afford pyrazoles and (spiro)pyrazolines have been reported. Mechanistic and DFT studies suggested the non-covalent interactions promote the reaction.
Article
Chemistry, Multidisciplinary
Yu Zhang, Yanchuan Li, Shao-Fei Ni, Jin-Peng Li, Dingding Xia, Xinyu Han, Jingchuan Lin, Jinxin Wang, Shoubhik Das, Wei-Dong Zhang
Summary: Visible-light-induced [3+2] cycloadditions of donor/donor diazo precursors with alkenes to afford pyrazoles and (spiro)pyrazolines have been reported. Mechanistic and DFT studies suggested the formation of non-covalent interactions promote the reaction.
Review
Chemistry, Multidisciplinary
Maedeh Bagheri, Shirin Mohammadsaeed, Parisa Gholamzadeh
Summary: The author believes that through the photography of Greek delicacies olive cake and coffee cake, Borg's efforts have popularized these pastries and promoted the exchange and sharing of culinary culture.
Article
Chemistry, Multidisciplinary
Tiansi Xin, Christopher C. Cummins
Summary: This study reports the synthesis and structural characterization of free, uncomplexed phosphet-2-ones for the first time. Unsaturated four-membered phosphacycles were prepared by phosphinidene transfer from dibenzo-7-phosphanorbornadiene compounds to cyclopropenones. The reaction is proposed to proceed through ketene-ylide and ketene-phosphaalkene intermediates. Further transformations of the phosphet-2-ones yielded more phosphet-2-ones and 1,2-dihydrophosphetes, including two furanone derivatives which are postulated to be produced by intramolecular phosphine-catalyzed [3 + 2] annulations.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Xinyu Chen, Na Yang, Wen Zeng, Lei Wang, Pinhua Li, Hongji Li
Summary: A mild dearomative [5+2]/[2+2] cycloaddition of 1H-indoles with ortho-(trimethylsilyl)aryl triflates was reported, leading to the synthesis of dibenzo[b,e]azepine derivatives in moderate to good yields. Increasing steric hindrance at the C2-position of 1H-indoles directs the reaction towards a [2+2] cycloaddition pathway. Mechanistic investigations suggest that the reaction proceeds through a [2+2] cycloaddition followed by a ring expansion to form the [5+2] cycloaddition product.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Ranjeet A. Dhokale, Santosh B. Mhaske
Article
Chemistry, Organic
Ranjeet A. Dhokale, Santosh B. Mhaske
JOURNAL OF ORGANIC CHEMISTRY
(2017)
Article
Chemistry, Organic
Ranjeet A. Dhokale, Pramod R. Thakare, Santosh B. Mhaske
Article
Chemistry, Organic
Ranjeet A. Dhokale, Santosh B. Mhaske
Article
Chemistry, Organic
Ranjeet A. Dhokale, Frederick J. Seidl, Anand H. Shinde, Joel T. Mague, Shyam Sathyamoorthi
Summary: This study presents the first examples of tethered silanoxyiodination reactions of allylic alcohols, yielding useful silanediol organoiodide synthons with high regioselectivity and diastereocontrol. The reaction is scalable without loss of yield or selectivity, and the products serve as starting materials for various transformations. DFT calculations provide insights into the excellent 6-endo selectivity of this reaction, indicating kinetically and thermodynamically favored products.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Ranjeet A. Dhokale, Frederick J. Seidl, Shyam Sathyamoorthi
Summary: The study demonstrates that 1M aqueous HCl/THF or NaBH4/DMF can facilitate the demercurative ring-opening of cyclic organomercurial synthons into secondary silanol products bearing terminal alkenes. A two-step protocol allows for the rearrangement of primary allylic silanol substrates into cyclic organomercurials. Computational investigations indicate that the rearrangement is thermodynamically controlled and the di-tert-butylsilanol protecting group plays a crucial role in product selectivity.
Review
Chemistry, Multidisciplinary
Stephany M. Ramos De Dios, Virendra K. Tiwari, Christopher D. McCune, Ranjeet A. Dhokale, David B. Berkowitz
Summary: This review discusses biomacromolecule-assisted screening methods and the discovered chemical reactions. Enzymes, antibodies, and nucleic acids have all been used as sensors to detect product chirality. These biomacromolecule-based screens offer high sensitivity and selectivity, and they have been applied to discover new chemical transformations in synthetic organic chemistry.
Article
Chemistry, Organic
Anand H. Shinde, Ranjeet A. Dhokale, Joel T. Mague, Shyam Sathyamoorthi
Summary: We demonstrate the effectiveness of di-tert-butylsilanols as nucleophiles for the interception of palladium pi-allyl species. The optimized protocol allows for stereospecific cyclization reactions, providing blank slates for further functionalization.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Someshwar Nagamalla, Ranjeet A. Dhokale, Frederick J. Seidl, Joel T. Mague, Shyam Sathyamoorthi
Summary: The first examples of rearrangement reactions of allylic silanol substrates into linear ketone and 5-membered cyclic silanediol organomercurial products are presented in this study. The reactions are mediated by Hg(OTf)(2) and show differences in the use of base, solvent, and temperature. Mechanistic studies suggest that these products result from a series of cascading transformations in one pot, with a DFT analysis providing insights into the rearrangement process.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Meeting Abstract
Chemistry, Multidisciplinary
Stephany Ramos De Dios, Ranjeet Dhokale, Danielle Graham, David Berkowitz
ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY
(2019)
