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Search for "difunctionalization" in Full Text gives 57 result(s) in Beilstein Journal of Organic Chemistry.
Visible-light-mediated copper photocatalysis for organic syntheses
Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169
- thiocyanate to generate 4-alkyl/aryl-2-aminothiazoles. Mechanistic experiments demonstrated that the photocatalyst formed in situ from Cu(OAc)2 and ammonium thiocyanate promoted the intermolecular cyclization (Scheme 7). 3.2 Difunctionalization of alkenes The 1,2-difunctionalization of alkenes is a versatile
- strategy for the construction of complex molecules. The primary process involved in the 1,2-difunctionalization of alkenes catalyzed by copper complexes is an atom-transfer radical addition (ATRA). Copper complexes or copper-based photoredox-active complexes formed in situ serve as photocatalysts to
- with oxime esters. Oxo-azidation of vinyl arenes. Azidation/difunctionalization of vinyl arenes. Photoinitiated copper-catalyzed Sonogashira reaction. Alkyne functionalization reactions. Alkynylation of dihydroquinoxalin-2-ones with terminal alkynes. Decarboxylative alkynylation of redox-active esters
Photoredox catalysis in nickel-catalyzed C–H functionalization
Beilstein J. Org. Chem. 2021, 17, 2209–2259, doi:10.3762/bjoc.17.143
- regenerate the nickel(0) species 21-VI and the carboxylate product 21-IX. Olefin difunctionalization Nickel-catalyzed alkene 1,2-difunctionalization is considered as useful method for preparing complex molecules in a single-step reaction [137][138][139]. In this aspect, the groups by Kong [140] and Molander
- -acylsuccinimides. Proposed catalytic cycle for the photoredox nickel-catalyzed aldehyde C–H functionalization. Proposed mechanism for the photoredox carboxylation of methylbenzenes with CO2. Proposed catalytic cycle for the decatungstate photo-HAT and nickel catalysis enabled alkene difunctionalization. Proposed
Asymmetric organocatalyzed synthesis of coumarin derivatives
Beilstein J. Org. Chem. 2021, 17, 1952–1980, doi:10.3762/bjoc.17.128
- yields and enantioselectivities when subjected to four sequential reactions mediated by a cooperative catalysis of a NHC organocatalyst with LiCl in the presence of DPQ as an oxidant, as shown in Scheme 17. Recently, Chen et al. used a NHC catalyst 59 in γ,δ-difunctionalization of coumarins 56 through an
On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets
Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126
- were found to be unreactive, probably due to steric hindrance. The one-pot difunctionalization of arenes involving a sequential C–O cleavage and C(sp2)–H activation mediated by chromium was recently reported by Luo and Zeng [124]. The reaction allows an ortho-directed diarylation of o
- reaction was kept at room temperature to avoid the difunctionalization, and the oxidant was added only in the second step. Following this route, six examples were obtained with moderate yields (56–70%, Scheme 16C). Although the use of chromium catalysis is still considered challenging due to the high
α,γ-Dioxygenated amides via tandem Brook rearrangement/radical oxygenation reactions and their application to syntheses of γ-lactams
Beilstein J. Org. Chem. 2021, 17, 688–704, doi:10.3762/bjoc.17.58
- defined combinations of chiral epoxides and chiral amides. This represents a very rare example of an oxidative geminal C–C/C–O difunctionalization next to carbonyl groups. The resulting dioxygenated allylic amides are subsequently subjected to persistent radical effect-based 5-exo-trig radical cyclization
- -allylic 2-silylacetamides would provide an intermediate alkoxide from which the Brook rearrangement and subsequent oxygenation could proceed (Scheme 1C). This represents in the event a geminal C–C/C–O difunctionalization of amide 8 and results in the α,γ-dioxygenated N-allylic amides 9. Thermal radical
- represents an oxidative C–C/C–O difunctionalization at the α-position of the amides. With correct configuration combination of chiral epoxides 7 and chiral amides 8, 2,4-dioxygenated amides 9 can be obtained with good anti-diastereoselectivity and enantioselectivity. Dioxygenated amides 9 are convenient
Metal-free visible-light-enabled vicinal trifluoromethyl dithiolation of unactivated alkenes
Beilstein J. Org. Chem. 2021, 17, 551–557, doi:10.3762/bjoc.17.49
- , Nanjing 210023, China School of pharmacy, Wannan Medical College, Wuhu, 241002, China 10.3762/bjoc.17.49 Abstract The difunctionalization of alkenes involving a trifluoromethylthio group (SCF3) for the conversion of versatile and readily available olefins into structurally more complex molecules has been
- . Keywords: alkenes; difunctionalization; metal-free; photoredox; trifluoromethylthiolation; Introduction The incorporation of fluorine atoms into drug molecules will significantly enhance the physical, chemical, and biological properties of the pharmaceuticals [1][2][3][4][5][6]. Modifying drug candidates
- ][16][17]. The vicinal difunctionalization of olefins to introduce two functional groups across a double bond has appeared as a powerful transformation to rapidly increase molecular complexity in synthetic chemistry with improved efficiency [18][19][20][21][22]. Various transition-metal-mediated
Silver-catalyzed synthesis of β-fluorovinylphosphonates by phosphonofluorination of aromatic alkynes
Beilstein J. Org. Chem. 2020, 16, 3086–3092, doi:10.3762/bjoc.16.258
- is the most rapid and convenient one (Scheme 1). Although studies on alkyne difunctionalization are ongoing [23], the successful attachment of a fluorine atom to the resulting alkene through transition metal catalysis remains a challenge. In particular, the phosphonofluorination of alkynes for the
- introduction of two strong electron-withdrawing groups into double bonds has not yet been reported. With our continuous interest in, and inspiration from the well-established transition metal-catalyzed radical difunctionalization of unsaturated carbon–carbon bonds, specifically the work of Li’s group and
- substrate scope and excellent functional group tolerance, this simple protocol may represent a general, one-step approach for the preparation of β-fluorophosphonate frameworks for the use in medicinal chemistry. Metal-catalyzed difunctionalization of unsaturated carbon–carbon bonds. Substrate scope for the
Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis
Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103
- cations and radical anions) Recently, the exploitation of alkenyl and aryl radical ions has emerged as a platform for the functionalization of small molecules. They appear as attractive intermediates for a direct alkene difunctionalization or arene C–H functionalization. In particular, radical cations are
Recent advances in photocatalyzed reactions using well-defined copper(I) complexes
Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42
- witnessed. 1.1 ATRA reactions Atom transfer radical addition reactions are linchpin transformations in organic synthesis as they allow an easy difunctionalization of alkenes. Usually, these reactions require the use of a radical initiator or thermal activation to initiate the radical chain. Recently
Copper-promoted/copper-catalyzed trifluoromethylselenolation reactions
Beilstein J. Org. Chem. 2020, 16, 305–316, doi:10.3762/bjoc.16.30
- group of Liang reported the difunctionalization of terminal styrenes and arylacetylene derivatives by introducing SeCF3 with the [(bpy)CuSeCF3]2 copper complex developed by the group of Weng and difluoroalkyl groups with ICF2CO2Et (Scheme 8) [25]. Only six examples were reported, with good yields
- heterocycles with [(bpy)CuSeCF3]2 by the group of Weng. Difunctionalization of terminal alkenes and alkynes with [(bpy)CuSeCF3]2 by the group of Liang. Synthesis of Me4NSeCF3. Oxidative trifluoromethylselenolation of terminal alkynes and boronic acid derivatives with Me4NSeCF3 by the group of Rueping
Synthesis and optoelectronic properties of benzoquinone-based donor–acceptor compounds
Beilstein J. Org. Chem. 2019, 15, 2914–2921, doi:10.3762/bjoc.15.285
- difunctionalization is dependent on the electronics of the substituent added to BQ) [14], 5 was instead furnished from the dibromo-functionalized BQ 1-Br2 using a double Suzuki coupling. As expected, much harsher conditions (100 °C) were required to achieve conversions under Pd(0) catalysis to produce 5 in 22% yield
α-Photooxygenation of chiral aldehydes with singlet oxygen
Beilstein J. Org. Chem. 2019, 15, 2076–2084, doi:10.3762/bjoc.15.205
- substituents into an aldehydes’ structure. Interestingly, to the best of our knowledge, there are no reports on ‘one-pot’ reactions leading to difunctionalization at both α and β-positions. To this end, in subsequent experiments, we attempted to merge two photochemical processes: β-benzylation (according to
- ). Photochemical difunctionalization of cinnamaldehyde (12) at the β and α-positions. Supporting Information Supporting Information File 416: Photochemical equipment, experiments for the optimization of the one-pot procedure, analytical data for 7, 8, 10, 11, HPLC chromatograms, and NMR spectra. Acknowledgements
Vicinal difunctionalization of alkenes by four-component radical cascade reaction of xanthogenates, alkenes, CO, and sulfonyl oxime ethers
Beilstein J. Org. Chem. 2019, 15, 1822–1828, doi:10.3762/bjoc.15.176
- difunctionalization of alkenes by four-component radical cascade reaction using xanthogenate 1, alkenes 2, CO, and sulfonyl oxime ethers 3 leading to 5a–l. Reaction conditions: 1 (0.4 mmol), 2 (4 mmol), CO (130 atm), 3 (0.5 mmol), DTBHN (30 mol %), (Bu3Sn)2 (0.8 mmol), DCE (8 mL), 45 °C, 16 h. Proposed radical chain
Homo- and hetero-difunctionalized β-cyclodextrins: Short direct synthesis in gram scale and analysis of regiochemistry
Beilstein J. Org. Chem. 2019, 15, 710–720, doi:10.3762/bjoc.15.66
- , Hungary Institute of Nanoscience and Nanotechnology National Center for Scientific Research “Demokritos”, Patr. Gregoriou E & 27 Neapoleos str., Aghia Paraskevi Attikis 15341, Greece 10.3762/bjoc.15.66 Abstract The regioselective difunctionalization of cyclodextrins (CDs) leading to derivatives amenable
- to further transformations is a daunting task due to challenging purification and unambiguous characterization of the obtained regioisomers with similar physicochemical properties. The primary-side homo-difunctionalization of β-CD can lead to three regioisomers, while the hetero-difunctionalization
- can generate three pairs of pseudoenantiomers. Previously, approaches with several synthetic steps, expensive reagents, high purification demands and low yields of the products have been employed. Herein we present direct, short and efficient primary-side difunctionalization strategies featuring
Tandem copper and photoredox catalysis in photocatalytic alkene difunctionalization reactions
Beilstein J. Org. Chem. 2019, 15, 351–356, doi:10.3762/bjoc.15.30
- Nicholas L. Reed Madeline I. Herman Vladimir P. Miltchev Tehshik P. Yoon Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States 10.3762/bjoc.15.30 Abstract Oxidative alkene difunctionalization reactions are important in synthetic
- that are not accessible from the native reactivity of the organoradical intermediates by themselves. Our laboratory is interested in the design of photochemical strategies for oxidative functionalization reactions [15][16]. We recently described [17] a new approach to alkene difunctionalization that
- ) complex. We describe herein the results of this investigation, which has led to the identification of a tandem photoredox copper(II) catalytic system for the net-oxidative difunctionalization of alkenes. Results and Discussion A range of mild oxidants can oxidize copper(I) to copper(II), and the use of
Hypervalent iodine compounds for anti-Markovnikov-type iodo-oxyimidation of vinylarenes
Beilstein J. Org. Chem. 2018, 14, 2146–2155, doi:10.3762/bjoc.14.188
- syntheses. In the row of organohalides, iodides are the most reactive and versatile reagents for the following transformations [60]. One of the purposes of our work was to introduce iodine in the process of difunctionalization of styrenes with imide-N-oxyl radicals. Iodine atom in the product can act as a
- styrene (1a, purple), NHPI (2a, red), I2 (blue) and PhI(OAc)2 (green) in 0.1 M n-Bu4NBF4/MeCN at a scan rate of 100 mV/s on a working glassy-carbon electrode. Difunctionalization of double C=C bond with the formation of C–O and C–I bonds. Iodo-oxyimidation of styrenes 1a–k with preparation of products 3aa
β-Hydroxy sulfides and their syntheses
Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143
- . Regioselective epoxide ring opening and 1,2-difunctionalization of alkenes are the commonly employed routes in the synthesis of such compounds. Both strategies are discussed below. 3.1 Synthesis of β-hydroxy sulfides via regioselective ring opening of epoxides The considerable ring strain present in epoxides
- ]-3-oxo-N-o-tolylbutanamides) [61] and S-alkylisothiouronium salts [62]. 3.2 Synthesis of β-hydroxy sulfides via difunctionalization of alkenes Although the synthesis of β-hydroxy sulfides via the thiolysis of epoxides is important, its Achilles’ heel is the need for the preparation of an epoxide
- alkyl radicals than the corresponding diaryl disulfides and benzyl radicals, respectively, are presumed to be the reasons behind the failure of the reaction to work with aliphatic alkenes [67]. 3.3. Synthesis of masked β-hydroxy sulfides via difunctionalization of alkenes Alkenes are versatile
Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis
Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128
- of copper(I) iodide as a catalyst for the regioselective difunctionalization of aromatic alkynes and alkenes with an optimal atom-economy (Scheme 4a) [34][35]. The transformation proceeds efficiently, particularly in the presence of an electron-donating substituent on the aromatic ring. The same
- complex. The group of Sodeoka, in parallel, has described the same 1,2-difunctionalization reaction of alkenes and alkynes with 5 in the presence of [Cu(MeCN)4]PF6 as the catalyst (Scheme 5a) [37]. It should be pointed out that this copper(I) complex was previously described by Szabó as a poor catalyst in
- derivatives. This relayed strategy can therefore be applied to non-symmetrical cyclic diaryliodonium species, thereby affording a library of functionalized benzoxazoles 58 with complete regiocontrol. The group of Zhang has developed a one-pot procedure for the sequential difunctionalization of cyclic diaryl
A survey of chiral hypervalent iodine reagents in asymmetric synthesis
Beilstein J. Org. Chem. 2018, 14, 1244–1262, doi:10.3762/bjoc.14.107
- electrophilicity and appreciable oxidizing properties. The transformations associated with asymmetric induction mainly focused on the asymmetric oxidation and oxidative dearomatization chemistry. Asymmetric difunctionalization of alkenes, α-functionalization of carbonyls and also some typical 1,2-aryl
- ) reagent 9b was used successively for the synthesis of δ-lactones 45 in a highly stereoselective manner starting from 44 [43]. The formation of cyclic iodonium 46 is the vital part of this difunctionalization process. Wirth et al. were the first to introduce asymmetric dioxytosylation of styrene (47) using
- 52. Fujita et al. further explored the difunctionalization strategy for the development of diacetoxylation of alkenes following a Prevost and Woodward reaction [48]. Recently, the same group used chiral iodine reagent 55 together with acid co-reagent for the intramolecular oxyarylation and
Iodine(III)-mediated halogenations of acyclic monoterpenoids
Beilstein J. Org. Chem. 2018, 14, 1103–1111, doi:10.3762/bjoc.14.96
- more user-friendly protocols that rely on Oxone® [20], DIB [24], or PIFA [25] since the iodide source is an iodide salt and not molecular iodine. Chlorination In the case of chlorination, we have yet to observe adducts arising from the vicinal difunctionalization of the double bond and, in accordance
Chlorination of phenylallene derivatives with 1-chloro-1,2-benziodoxol-3-one: synthesis of vicinal-dichlorides and chlorodienes
Beilstein J. Org. Chem. 2018, 14, 796–802, doi:10.3762/bjoc.14.67
- pathways. For example, Liu and co-workers used Togni’s benziodoxolone reagent [35] in a radical-mediated vicinal 2,3-difunctionalization of allenes, which proceeded via CF3-radical adduct A (Scheme 1a) [36]. In contrast, Muñiz reported that with PhI(NTs2)2, an oxidative amination occurred via cation B
Enantioselective dioxytosylation of styrenes using lactate-based chiral hypervalent iodine(III)
Beilstein J. Org. Chem. 2018, 14, 659–663, doi:10.3762/bjoc.14.53
- )-isomer. Keywords: 1,2-difunctionalization of alkenes; enantioselective synthesis; hypervalent iodine; oxidation; Findings Hypervalent aryl-λ3-iodanes have been widely used for metal-free oxidation with high selectivity in organic synthesis [1][2][3]. The reactivity of an aryl-λ3-iodane is controlled by
- for highly stereocontrolled oxidative transformations [4][5][6][7][8][9][10][11][12][13][14]. The enantioselective vicinal difunctionalization of alkenes constitutes one type of attractive transformation achieved by chiral hypervalent iodine compounds. As a seminal example in this field, Wirth et al
- ][28][29], and vicinal difunctionalization of alkenes [18][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50]. Here, the efficiency of the lactate-based chiral hypervalent iodine reagents 4a–e (Figure 1) was assessed using the dioxytosylation of styrenes as a reference
Difunctionalization of alkenes with iodine and tert-butyl hydroperoxide (TBHP) at room temperature for the synthesis of 1-(tert-butylperoxy)-2-iodoethanes
Beilstein J. Org. Chem. 2017, 13, 2023–2027, doi:10.3762/bjoc.13.200
- , Maoming 525000, P. R. China. Fax: +86-668-2923575; Tel: +86-668-2923956 10.3762/bjoc.13.200 Abstract We developed a direct vicinal difunctionalization of alkenes with iodine and TBHP at room temperature. This iodination and peroxidation in a one-pot synthesis produces 1-(tert-butylperoxy)-2-iodoethanes
- applications and allow further chemical modifications, enabling the preparation of synthetically valuable molecules. Keywords: difunctionalization of alkenesiodine; iodination–peroxidation reaction; TBHP; Introduction Alkenes have attracted considerable interest in recent years as abundant, simple chemical
- feedstocks and organic molecules, owing to their potential for extensive application in organic syntheses. Approaches for the efficient, regio- and chemoselective difunctionalization of alkenes have been developed that are attractive for rapidly building complex difunctionalized molecules from simple
Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones
Beilstein J. Org. Chem. 2016, 12, 301–308, doi:10.3762/bjoc.12.32
- mixture was charged onto silica gel and purified by flash chromatography to furnish the corresponding products 5 and 7. Cascade 1,2-difunctionalization and cyclization to construct heterocycles. Cyclization of cyclohexane (2a) with substituted N-(2-methylallyl)benzamide (reaction conditions: 4 (0.2 mmol
Copper-catalyzed intermolecular oxyamination of olefins using carboxylic acids and O-benzoylhydroxylamines
Beilstein J. Org. Chem. 2016, 12, 22–28, doi:10.3762/bjoc.12.4
- -benzoylhydroxylamines as an electrophilic amine source and carboxylic acids as a nucleophilic oxygen source to achieve a modular difunctionalization of olefins. The reaction proceeded in a regioselective manner with moderate to good yields, exhibiting a broad scope of carboxylic acid, amine, and olefin substrates
- Liu reported a palladium-catalyzed introduction of phthalimide (HNPhth) and acetate functionalities to terminal allylic and homoallylic ethers in the presence of an iodine oxidant (Scheme 1B) [13]. The Yoon lab also developed copper- and iron-catalyzed olefin difunctionalization reactions with
- transformation, integrating an electrophilic amination with a nucleophilic oxygenation, builds upon our recent development in copper-catalyzed olefin difunctionalization, such as copper-catalyzed diamination [40] and amino lactonization [34]. This strategy overcomes common issues of chemo- and regioselectivity
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