Search results

Search for "transmetalation" in Full Text gives 75 result(s) in Beilstein Journal of Organic Chemistry.

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

  • Lucas Guillemard and
  • Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

Graphical Abstract
PDF
Album
Review
Published 21 Jul 2020

Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones

  • Valeria Nori,
  • Antonio Arcadi,
  • Armando Carlone,
  • Fabio Marinelli and
  • Marco Chiarini

Beilstein J. Org. Chem. 2020, 16, 1084–1091, doi:10.3762/bjoc.16.95

Graphical Abstract
  • halides [38], α-iodoenones [39], or by transmetalation of a Pd(II) species with boronic acids [33]. In this context, we decided to explore the use of substrates 2 in the reaction with 2-alkynyltrifluoroacetanilides 5 through a sequential cyclocarbopalladation/aminopalladation/reductive elimination process
  • containing electron-donating substituents; electron-poor arylboronic acids proved to be slightly less effective, probably because of their lower nucleophilicity that could have affected the transmetalation step. Moreover, we screened the reaction of a number of aromatic boronic acids 3a–j with a set of N
PDF
Album
Supp Info
Full Research Paper
Published 20 May 2020

Copper-catalyzed enantioselective conjugate reduction of α,β-unsaturated esters with chiral phenol–carbene ligands

  • Shohei Mimura,
  • Sho Mizushima,
  • Yohei Shimizu and
  • Masaya Sawamura

Beilstein J. Org. Chem. 2020, 16, 537–543, doi:10.3762/bjoc.16.50

Graphical Abstract
  • protons of the acidic imidazolium C–H and phenol O–H groups of the L4·HBF4 adduct in the presence of CuCl to generate a phenoxy copper(I) species A. As a result, all LiOt-Bu (20 mol %) is consumed in this step. Thus, the system is neutral. Transmetalation between A and (EtO)2MeSiH produces the copper
  • hydride species B. This transmetalation adds the silyl group to the phenoxy oxygen atom of the NHC ligand. The coordination of an α,β-unsaturated carbonyl compound 1 to the copper atom occurs in such a way that the bulky O-silyl group of the copper catalyst can avoid steric repulsions with the
PDF
Album
Supp Info
Full Research Paper
Published 31 Mar 2020

Architecture and synthesis of P,N-heterocyclic phosphine ligands

  • Wisdom A. Munzeiwa,
  • Bernard Omondi and
  • Vincent O. Nyamori

Beilstein J. Org. Chem. 2020, 16, 362–383, doi:10.3762/bjoc.16.35

Graphical Abstract
  • accessible using the transmetalation route B and C from compound 100 and 101, respectively. The phenyl phosphine derivatives, using the metal-catalyzed phosphorylation route A, and lower yields (14%) were obtained compared to the transmetalation route C. P–H Bond addition to unsaturated precursors The
PDF
Album
Review
Published 12 Mar 2020

A new approach to silicon rhodamines by Suzuki–Miyaura coupling – scope and limitations

  • Thines Kanagasundaram,
  • Antje Timmermann,
  • Carsten S. Kramer and
  • Klaus Kopka

Beilstein J. Org. Chem. 2019, 15, 2569–2576, doi:10.3762/bjoc.15.250

Graphical Abstract
  • ). Again, the reaction catalyzed by PdCl2(dppf) resulted in an enhanced yield compared to catalysis with PdCl2(PPh3)2. Next we aimed at the synthesis of a silicon rhodamine bearing an acid function in 2’-position. With a less bulky methyl ester in the 2’-position of the phenylboroxine, the transmetalation
PDF
Album
Supp Info
Full Research Paper
Published 29 Oct 2019

Functionalization of 4-bromobenzo[c][2,7]naphthyridine via regioselective direct ring metalation. A novel approach to analogues of pyridoacridine alkaloids

  • Benedikt C. Melzer,
  • Alois Plodek and
  • Franz Bracher

Beilstein J. Org. Chem. 2019, 15, 2304–2310, doi:10.3762/bjoc.15.222

Graphical Abstract
  • ]. Reaction of allyl iodide (17) with metalated 9d after addition of catalytic amounts of CuCN∙2LiCl led to the formation of the 5-allyl compound 18 in 37% yield. Metalation of 9d using TMPMgCl∙LiCl and subsequent transmetalation with ZnCl2 followed by Negishi cross-coupling reaction in the presence of Pd(dba
PDF
Album
Supp Info
Full Research Paper
Published 26 Sep 2019

Borylation and rearrangement of alkynyloxiranes: a stereospecific route to substituted α-enynes

  • Ruben Pomar Fuentespina,
  • José Angel Garcia de la Cruz,
  • Gabriel Durin,
  • Victor Mamane,
  • Jean-Marc Weibel and
  • Patrick Pale

Beilstein J. Org. Chem. 2019, 15, 1416–1424, doi:10.3762/bjoc.15.141

Graphical Abstract
  • in organic synthesis [1][2]. Such species can undergo different reactions, driven either by their carbanionic or carbenic behavior [3][4], thus leading to various products. In contrast, the transmetalation of lithiated oxiranes and the evolution of the resulting species have been less explored
  • ]. Alternatively, Unemaya et al. and more recently Buchwald et al. described a Negishi cross coupling of aryl bromides or chlorides to α-CF3-oxiranyl zincates generated by lithiation of trifluoromethyloxirane and transmetalation with zinc chloride [10][11]. In this context and based on the pioneering work of
PDF
Album
Supp Info
Full Research Paper
Published 27 Jun 2019

Diastereo- and enantioselective preparation of cyclopropanol derivatives

  • Marwan Simaan and
  • Ilan Marek

Beilstein J. Org. Chem. 2019, 15, 752–760, doi:10.3762/bjoc.15.71

Graphical Abstract
  • cyclopropylmagnesium species 6MgBr, the selective oxidation reaction of the copper species, resulting from a transmetalation reaction, was similarly achieved by reaction with oxenoid [71][79][80][86][87][88][89]. In all cases, cyclopropanols 7 were obtained as single diastereoisomer (dr 98:2:0:0) with excellent
PDF
Album
Supp Info
Full Research Paper
Published 21 Mar 2019

Nucleofugal behavior of a β-shielded α-cyanovinyl carbanion

  • Rudolf Knorr and
  • Barbara Schmidt

Beilstein J. Org. Chem. 2018, 14, 3018–3024, doi:10.3762/bjoc.14.281

Graphical Abstract
  • acrylonitrile derivative 1 or by an Sn/Li transmetalation reaction of n-butyllithium (“n-BuLi”) with the α-stannyl derivative 3. Due to intermolecular LiN coordination, 2Li was deduced [4] to form a clustered ground state that showed no obvious rate anomaly with previously [4] studied electrophiles; this should
PDF
Album
Supp Info
Full Research Paper
Published 11 Dec 2018

Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source

  • Tetsuaki Fujihara and
  • Yasushi Tsuji

Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221

Graphical Abstract
  • transmetalation between D and AlMe3, with the concomitant regeneration of methyl-Co(I) A (step d). Carboxyzincation of alkynes The good reactivity and high functional-group compatibility of organozinc compounds render them as important reagents in organic synthesis [38][39]. For their preparation, direct and
  • reduced to Co(I) (A) in the presence of metallic Zn. The oxidative cyclization of A with alkyne 16 and CO2 affords cobaltacycle B (step a). Next, the transmetalation between B and the Zn(II) species occurs, which affords the alkenylzinc intermediate C (step b) [41], which is then reduced with Zn powder
  • formed (step a) [42]. Then, the insertion of CO2 into the Co–C(sp3) bond occurs, and the seven-membered Co intermediate C is obtained (step b). The transmetalation of C with the Zn(II) species proceeds then to afford the alkenylzinc species D (step c). The subsequent two-electron reduction of D with Zn
PDF
Album
Review
Published 19 Sep 2018

Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine

  • Piotr Pomarański,
  • Piotr Roszkowski,
  • Jan K. Maurin,
  • Armand Budzianowski and
  • Zbigniew Czarnocki

Beilstein J. Org. Chem. 2018, 14, 2384–2393, doi:10.3762/bjoc.14.214

Graphical Abstract
  • with ortho-substituted phenylboronic acid for triaryl products. Summary of results for coupling with ortho-substituted phenylboronic acid for diaryl products. Proposed intermediates for the 1,2-addition of 5 with methoxy group. A) Oxidative addition step. B) Transmetalation step. Proposed intermediates
  • for the 1,3-addition with methoxy group. A) Oxidative addition step. B) Transmetalation step. Proposed intermediates for the 1,2-addition with chlorine atom. A) Oxidative addition step. B) Transmetalation step. Proposed intermediates for the 1,3-addition with chlorine atom. A) Oxidative addition step
  • . B) Transmetalation step. Optimization for the synthesis 6–9. Compound 10 was not detected in the mixture. Optimization of the synthesis of compounds 1–3. Rotational barriers of compounds 7 and 10. Optimization of the reaction conditions for the synthesis of 12–14. Optimization of the reaction
PDF
Album
Supp Info
Full Research Paper
Published 11 Sep 2018

Cobalt-catalyzed nucleophilic addition of the allylic C(sp3)–H bond of simple alkenes to ketones

  • Tsuyoshi Mita,
  • Masashi Uchiyama,
  • Kenichi Michigami and
  • Yoshihiro Sato

Beilstein J. Org. Chem. 2018, 14, 2012–2017, doi:10.3762/bjoc.14.176

Graphical Abstract
  • would lead to a low-valent allylcobalt(I) species, and then C–C bond formation of IV with 2a would proceed at the γ-position to produce cobalt alkoxide(I) V [28][29][31][32][33][34][35][36][37][38][39]. Transmetalation between V and AlMe3 would furnish branched aluminium alkoxide VI along with the
PDF
Album
Supp Info
Letter
Published 02 Aug 2018

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

  • Gwendal Grelier,
  • Benjamin Darses and
  • Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

Graphical Abstract
  • and migratory addition into the proximal alkyne. Transmetalation of the vinylpalladium with the boronic acid and reductive elimination finally leads to alkylidenefluorenes 49. This multicomponent strategy allows the variation of the alkyne, the boronic acid and the diaryliodonium salts, but the use of
PDF
Album
Review
Published 21 Jun 2018

Three-component coupling of aryl iodides, allenes, and aldehydes catalyzed by a Co/Cr-hybrid catalyst

  • Kimihiro Komeyama,
  • Shunsuke Sakiyama,
  • Kento Iwashita,
  • Itaru Osaka and
  • Ken Takaki

Beilstein J. Org. Chem. 2018, 14, 1413–1420, doi:10.3762/bjoc.14.118

Graphical Abstract
  • , leading to multi-substituted carbon frameworks (Scheme 1, bottom) [2][3]. The nucleophilic and π-electrophilic organometallic intermediates are used properly in their favorable circumstances. Transmetalation is one of the most vital elemental processes used to drastically change the reactivity of
  • organometallics, involving a wide range of transition metal-catalyzed reactions. For example, transmetalation between an organonickel (or organocobalt) complex and chromium salt results in the formation of a highly nucleophilic organochromium species, which enables efficient addition to aldehydes to give
  • alkynyl iodoarene cyclization/borylation to form cyclized vinylboronic esters, in which transmetalation between the generated vinylcobalt and chromium salt was a critical step (Scheme 4) [16]. As part of our continuing work on the cobalt-catalyzed functionalization of carbon–carbon unsaturated bonds, a
PDF
Album
Supp Info
Full Research Paper
Published 11 Jun 2018

Cobalt-catalyzed directed C–H alkenylation of pivalophenone N–H imine with alkenyl phosphates

  • Wengang Xu and
  • Naohiko Yoshikai

Beilstein J. Org. Chem. 2018, 14, 709–715, doi:10.3762/bjoc.14.60

Graphical Abstract
  • radical to give a diorganocobalt intermediate C. The C–C-bond rotation of the radical anion 2•− or the transiently formed alkenyl radical might be responsible for the stereochemical mutation of the C=C bond observed in some cases. The reductive elimination of C and subsequent transmetalation with the
PDF
Album
Supp Info
Full Research Paper
Published 28 Mar 2018

Progress in copper-catalyzed trifluoromethylation

  • Guan-bao Li,
  • Chao Zhang,
  • Chun Song and
  • Yu-dao Ma

Beilstein J. Org. Chem. 2018, 14, 155–181, doi:10.3762/bjoc.14.11

Graphical Abstract
  • mechanistic studies (Scheme 35). First, the key intermediate CF3CuILn is generated in situ by the reaction of TMSCF3 with Cu(II) reagent, followed by transmetalation with activated Ar−H generating the (aryl)CuI(CF3) species C, which might be oxidized to the corresponding (aryl)CuIII(CF3) intermediate D
PDF
Album
Review
Published 17 Jan 2018

Recent progress in the racemic and enantioselective synthesis of monofluoroalkene-based dipeptide isosteres

  • Myriam Drouin and
  • Jean-François Paquin

Beilstein J. Org. Chem. 2017, 13, 2637–2658, doi:10.3762/bjoc.13.262

Graphical Abstract
  • bearing a N-enoyl sultam moiety 84 instead. A 3-key step strategy involving a copper-mediated reduction, a transmetalation and an asymmetric alkylation was adopted for the preparation of monofluoroalkenes 85 (Scheme 16). After some synthetic modifications, Fmoc-Orn(Ns)-ψ[(Z)-CF=CH]-Orn(Ns) [48], Fmoc-Lys
  • reduction, transmetalation and asymmetric alkylation by Fujii and co-workers. Synthesis of (E)-monofluoroalkene-based dipeptide isostere by Fujii and co-workers. Diastereoselective synthesis of MeOCO-Val-ψ[(Z)-CF=C]-Pro isostere by Chang and co-workers. Asymmetric synthesis of Fmoc-Ala-ψ[(Z)-CF=C]-Pro by
PDF
Album
Review
Published 12 Dec 2017

The chemistry and biology of mycolactones

  • Matthias Gehringer and
  • Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

Graphical Abstract
PDF
Album
Review
Published 11 Aug 2017

A novel approach to oxoisoaporphine alkaloids via regioselective metalation of alkoxy isoquinolines

  • Benedikt C. Melzer and
  • Franz Bracher

Beilstein J. Org. Chem. 2017, 13, 1564–1571, doi:10.3762/bjoc.13.156

Graphical Abstract
  • were inspired by Knochel’s reports on the direct metalation of isoquinoline [22] and 6,7-dimethoxyisoquinoline [23] as well as by our own results for the metalation of various alkoxyisoquinolines [13] at C-1 with the Knochel–Hauser base TMPMgCl·LiCl. Transmetalation of the intermediate organomagnesium
  • extended to 6-methoxyisoquinoline (7c). Unfortunately, transmetalation with ZnCl2 at 0 °C followed by palladium-catalyzed (5 mol % Pd(dba)2/ 10 mol % P(2-furyl)3 or 1 mol % Pd2(dba)3/2 mol % RuPhos) Negishi cross-coupling reaction with methyl 2-bromo-5-methoxybenzoate did not lead to the expected methyl 2
PDF
Album
Supp Info
Full Research Paper
Published 08 Aug 2017

Direct catalytic arylation of heteroarenes with meso-bromophenyl-substituted porphyrins

  • Alexei N. Kiselev,
  • Olga K. Grigorova,
  • Alexei D. Averin,
  • Sergei A. Syrbu,
  • Oskar I. Koifman and
  • Irina P. Beletskaya

Beilstein J. Org. Chem. 2017, 13, 1524–1532, doi:10.3762/bjoc.13.152

Graphical Abstract
  • ) metalates heteroarene in the presence of K2CO3 forming Het-Cu-OAc species and this process proceeds faster than the oxidation of Pd(0). Then one may suppose the transmetalation reaction at heteroarene according to Scheme 4 which provides the formation of Ar-Pd-Het intermediate giving the target coupling
  • benzothiazole, benzoxazole, N-methylbenzimidazole and caffeine. Plausible action of palladium and copper catalysts with transmetalation step. Dirylation of zinc di-meso-(bromophenyl)porphyrinates 10–12 with benzothiazole, benzoxazole and N-methyl benzimidazole. Polyarylation of zinc tetrakis-meso-(bromophenyl
PDF
Album
Supp Info
Full Research Paper
Published 03 Aug 2017

A concise and practical stereoselective synthesis of ipragliflozin L-proline

  • Shuai Ma,
  • Zhenren Liu,
  • Jing Pan,
  • Shunli Zhang and
  • Weicheng Zhou

Beilstein J. Org. Chem. 2017, 13, 1064–1070, doi:10.3762/bjoc.13.105

Graphical Abstract
  • was developed. The route initiated from compound 4a and pivaloyl-protected glycosyl bromide 2b, the β-C-arylglucoside 5 was obtained with high stereoselectivity in one step after a halogen–lithium exchange/transmetalation/coupling sequence. Cryogenic temperatures and catalysts were not required. The
  • converted to the arylzinc species by the reaction with n-BuLi in the mixed solvent (toluene/DBE), followed by transmetalation with ZnBr/LiBr complex in DBE, and then the active species reacted with 2,3,4,6-tetra-O-pivaloyl-α-D-glucopyranosyl bromide (2b) [16]. But the reaction gave only 35% of desired 5
  • equiv 2b gave a good result, the amount of 5” was greatly reduced (Table 1, entry 4), while the content of 5 in the crude product was increased to 68% and the isolated yield was 77.7%. It was presumable that a iodine–lithium–zinc exchange and the transmetalation proceeded better than a bromide–lithium
PDF
Album
Supp Info
Full Research Paper
Published 01 Jun 2017

Synthesis of tetrasubstituted pyrazoles containing pyridinyl substituents

  • Josef Jansa,
  • Ramona Schmidt,
  • Ashenafi Damtew Mamuye,
  • Laura Castoldi,
  • Alexander Roller,
  • Vittorio Pace and
  • Wolfgang Holzer

Beilstein J. Org. Chem. 2017, 13, 895–902, doi:10.3762/bjoc.13.90

Graphical Abstract
  • -coupling reaction with organozinc compounds [23][24] is a valuable tool for the formation of C–C bonds, particularly in the presence of functional groups. The employed organozinc reagents are relatively reactive nucleophiles undergoing rapid transmetalation with appropriate transition metal species, for
PDF
Album
Supp Info
Full Research Paper
Published 12 May 2017

Rh-Catalyzed reductive Mannich-type reaction and its application towards the synthesis of (±)-ezetimibe

  • Motoyuki Isoda,
  • Kazuyuki Sato,
  • Yurika Kunugi,
  • Satsuki Tokonishi,
  • Atsushi Tarui,
  • Masaaki Omote,
  • Hideki Minami and
  • Akira Ando

Beilstein J. Org. Chem. 2016, 12, 1608–1615, doi:10.3762/bjoc.12.157

Graphical Abstract
  • enolate 7 involved the 1,4-reduction of α,β-unsaturated ester 2 by 6 and the transmetalation with a zinc species to give the Reformatsky-type reagent Int A. This intermediate Int A reacts immediately with the imine to give the corresponding intermediate Int B. Subsequently, intramolecular cyclization of
PDF
Album
Supp Info
Full Research Paper
Published 27 Jul 2016

Methylpalladium complexes with pyrimidine-functionalized N-heterocyclic carbene ligands

  • Dirk Meyer and
  • Thomas Strassner

Beilstein J. Org. Chem. 2016, 12, 1557–1565, doi:10.3762/bjoc.12.150

Graphical Abstract
  • = Cl, CF3COO, CH3) has been prepared by transmetalation reactions from the corresponding silver complexes and chloro(methyl)(cyclooctadiene)palladium(II). The dimethyl(1-(2-pyrimidyl)-3-(2,6-diisopropylphenyl)imidazolin-2-ylidene)palladium(II) complex was synthesized via the free carbene route. All
  • silver complexes 5–8 by transmetalation with chloro(methyl)(cyclooctadiene)palladium(II) [(COD)PdII(CH3)Cl] either in dichloromethane (A) or acetonitrile (B, Scheme 1). Although two isomers could be formed we only observed the isomer B, where the methyl group is located cis to the carbene carbon atom
PDF
Album
Supp Info
Full Research Paper
Published 21 Jul 2016

On the mechanism of imine elimination from Fischer tungsten carbene complexes

  • Philipp Veit,
  • Christoph Förster and
  • Katja Heinze

Beilstein J. Org. Chem. 2016, 12, 1322–1333, doi:10.3762/bjoc.12.125

Graphical Abstract
  • pentacarbonyl metal fragments (M = Cr, Mo, W) have further proven to be effective carbene transfer agents to late transition metals in transmetalation reactions [9][10][11][12][13][14][15]. The manifold synthetic access routes to carbene complexes even allows the assembly of multicarbene and multimetal carbene
PDF
Album
Supp Info
Full Research Paper
Published 27 Jun 2016
Other Beilstein-Institut Open Science Activities