One-pot functionalisation of N-substituted tetrahydroisoquinolines by photooxidation and tunable organometallic trapping of iminium intermediates

• Joshua P. Barham,
• Matthew P. John and
• John A. Murphy

Beilstein J. Org. Chem. 2014, 10, 2981–2988, doi:10.3762/bjoc.10.316

• 10.3762/bjoc.10.316 Abstract Nucleophilic trapping of iminium salts generated via oxidative functionalisation of tertiary amines is well established with stabilised carbon nucleophiles. The few reports of organometallic additions have limited scope of substrate and organometallic nucleophile. We report a

• demonstrated the former reason herein, investigation of the latter is underway to extend the substrate scope beyond benzylic tertiary amines. Examples of biologically active 1,2-disubstituted tetrahydroisoquinolines. Products from allylzinc reagent addition to 5a and 5b. Proposed mechanism for formation of

Synthesis of nanodiamond derivatives carrying amino functions and quantification by a modified Kaiser test

• Gerald Jarre,
• Steffen Heyer,
• Elisabeth Memmel,
• Thomas Meinhardt and
• Anke Krueger

Beilstein J. Org. Chem. 2014, 10, 2729–2737, doi:10.3762/bjoc.10.288

• to primary amines. Secondary amines cannot be detected reliably and aromatic and tertiary amines do not yield positive test results either [24]. One report on the non-quantitative application of the Kaiser test on ethylene diamine functionalized nanodiamond has been reported recently [25]. For

Efficient CO₂ capture by tertiary amine-functionalized ionic liquids through Li⁺-stabilized zwitterionic adduct formation

• Zhen-Zhen Yang and
• Liang-Nian He

Beilstein J. Org. Chem. 2014, 10, 1959–1966, doi:10.3762/bjoc.10.204

• influence of the anion on the nature of the coordinative bond. In the case of tertiary amines (e.g., PEG150MeBu2N), all the protons shifted downfield after forming the chelated IL with LiNTf2. Changing the anion to CF3SO3− had negligible influence on the coordination ability. All the neutral ligands shown

• -philic nature of the PEG chain facilitates CO2 sorption. Generally, anhydrous tertiary amines absorb CO2 only under high CO2 pressures to form instable zwitterionic alkylcarbonate salts (Table 1, entry 9) [42]. [PEG150MeBu2NLi][NTf2] and [PEG150MeBu2NLi][SO3CF3] were able to rapidly reach 0.66 and 0.61

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• to polymer backbones and side groups, including the addition of tertiary amines and pyridine (all analogues tested were insoluble) [91] and siloxanes (poly(dimethylsiloxane) (PDMS, Table 2, compound 24)), which has the highest solubility of all known non-fluorinated polymers in carbon dioxide [85][86

Preparation of phosphines through C–P bond formation

• Iris Wauters,
• Wouter Debrouwer and
• Christian V. Stevens

Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106

• palladium as a catalyst in the presence of tertiary amines as base. A variety of hydrophilic phosphines (102, 103) was synthesized. Since no protective groups were introduced, the method proves to be compatible with several functionalities. This methodology or in a slightly modified form has been used by

Visible-light-induced, Ir-catalyzed reactions of N-methyl-N-((trimethylsilyl)methyl)aniline with cyclic α,β-unsaturated carbonyl compounds

• Dominik Lenhart and
• Thorsten Bach

Beilstein J. Org. Chem. 2014, 10, 890–896, doi:10.3762/bjoc.10.86

• used for the formation of carbon–carbon bonds [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. In non-silylated tertiary amines, a proton can act as a leaving group and photoinduced addition reactions of tertiary amines to enones are long known [23][24][25][26][27][28]. Mechanistically

Polyglycerol-functionalized nanodiamond as a platform for gene delivery: Derivatization, characterization, and hybridization with DNA

• Li Zhao,
• Yuki Nakae,
• Hongmei Qin,
• Tadamasa Ito,
• Takahide Kimura,
• Hideto Kojima,
• Lawrence Chan and
• Naoki Komatsu

Beilstein J. Org. Chem. 2014, 10, 707–713, doi:10.3762/bjoc.10.64

• case of ND, for example, basic polypeptides [16], polyamine polymer [17], primary and tertiary amines [17][18], and quaternary ammonium salts [19] were employed to coat ND covalently or noncovalently as positively charged ligands for DNA immobilization. Although the functionalized ND is proven to

Continuous-flow Heck synthesis of 4-methoxybiphenyl and methyl 4-methoxycinnamate in supercritical carbon dioxide expanded solvent solutions

• Phei Li Lau,
• Ray W. K. Allen and
• Peter Styring

Beilstein J. Org. Chem. 2013, 9, 2886–2897, doi:10.3762/bjoc.9.325

• . Among them, tertiary amines such as triethylamine (Et3N), tributylamine (Bu3N) and alkali salts like carbonates, acetates or phosphates play crucial roles [7]. Solubility of the base and its basicity in the appropriate solvents are criteria that need to be considered. Traditionally, most Heck reactions

Advancements in the mechanistic understanding of the copper-catalyzed azide–alkyne cycloaddition

• Regina Berg and
• Bernd F. Straub

Beilstein J. Org. Chem. 2013, 9, 2715–2750, doi:10.3762/bjoc.9.308

• ], and fulfil the twofold role of base and ligand in organic solvents [90][91][92][93][94][95][96][97]. Although a variety of other tertiary amines such as propylamine [98][99] or tributylamine [100] has been employed, there is no comprehensive study about the influence of the nitrogen substituents. The

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

• aromatic amino acid residues, Tyr652 and Phe656, that are located in an exposed area within the S6 domain pointing towards the possibility of cation π-interactions explaining the affinity of drugs containing tertiary amines towards hERG channels. Consequently, careful and early-stage examination of hERG

The chemistry of amine radical cations produced by visible light photoredox catalysis

• Jie Hu,
• Jiang Wang,
• Theresa H. Nguyen and
• Nan Zheng

Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234

• ion is subsequently reduced to α-amino radical 132 by Ru(I). Back in 1986, the Whitten group established this pathway by irradiation of three substituted tertiary amines with Ru[4,4’-CO2Et(bpy)]3(PF6)2 respectively using visible light (Scheme 29) [101]. The identity of carbon radicals 130a and 130b

• azodicarboxylates. α-Arylation of amines. Plausible mechanism for α-arylation of amines. Photoinduced C–C bond cleavage of tertiary amines. Photoredox cleavage of C–C bonds of 1,2-diamines. Proposed mechanism photoredox cleavage of C–C bonds. Intermolecular [3 + 2] annulation of cyclopropylamines with olefins

Selective copper(II) acetate and potassium iodide catalyzed oxidation of aminals to dihydroquinazoline and quinazolinone alkaloids

• Matthew T. Richers,
• Chenfei Zhao and
• Daniel Seidel

Beilstein J. Org. Chem. 2013, 9, 1194–1201, doi:10.3762/bjoc.9.135

• , which contains two tertiary amines and is readily obtainable by an acid-promoted hydride shift process [52][53][54], was also exposed to oxidative conditions (Scheme 1, reaction 2). We had hypothesized that quinazolinone 32 might be formed in this reaction by the debenzylation of an intermediate iminium

Amyloid-β probes: Review of structure–activity and brain-kinetics relationships

• Todd J. Eckroat,
• Abdelrahman S. Mayhoub and
• Sylvie Garneau-Tsodikova

Beilstein J. Org. Chem. 2013, 9, 1012–1044, doi:10.3762/bjoc.9.116

• , have been widely reported as Aβ-imaging tracers (Scheme 2A). Structure–activity-relationship (SAR) studies on fluorinated chalcones 18a–l have shown that, in general, chalcones with tertiary amines in their structures demonstrate good affinity for Aβ plaques in in vitro models (Ki = 20–50 nM) (Table 1

• that the more lipophilic secondary and tertiary amines at the 4'-position were more potent (Ki) than primary amines. Also, in general, substitution at the 6-position seemed to have only a small effect in terms of Ki as 6-OH, -OCH3, -CN, and -Br gave similar results. However, substitution at the 6

• prepared [86]. These compounds, [18F]FPYBF-2 (123c) and [18F]FPHBF-2 (123d), have a secondary methylamino group in place of the dimethylamino group. Introduction of the secondary amine served to reduce lipophilicity. In addition, as the secondary amines are less rapidly metabolized than the tertiary amines

Spectroscopic characterization of photoaccumulated radical anions: a litmus test to evaluate the efficiency of photoinduced electron transfer (PET) processes

• Maurizio Fagnoni,
• Stefano Protti,
• Davide Ravelli and
• Angelo Albini

Beilstein J. Org. Chem. 2013, 9, 800–808, doi:10.3762/bjoc.9.91

• solution) in the presence of tertiary amines allowed the accumulation of the corresponding radical anions, up to quantitative yield for polysubstituted benzenes and partially with naphthalene and anthracene derivatives. The condition for such an accumulation was that the donor radical cation underwent

• those that react with it (path c'). Thus, tertiary amines are known to undergo deprotonation from the α-position to produce a radical that is in turn easily oxidized to the iminium cation. In the present examples, such radicals are oxidized by the ground-state sensitizer (E = −1.12 V versus SCE for the

• further tertiary amines, iPr3N causes a somewhat slower accumulation (the conformation of the radical cation is known to be less favorable for deprotonation) [48][49][50], and DABCO (for which deprotonation is impossible [51][52]) causes no detectable formation of TCB•−. Indeed, previous laser flash

Synthesis of 2,3-dihydronaphtho[2,3-d][1,3]thiazole-4,9-diones and 2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones and novel ring contraction and fusion reaction of 3H-spiro[1,3-thiazole-2,1'-cyclohexanes] into 2,3,4,5-tetrahydro-1H-carbazole-6,11-diones

• Lidia S. Konstantinova,
• Kirill A. Lysov,
• Ljudmila I. Souvorova and
• Oleg A. Rakitin

Beilstein J. Org. Chem. 2013, 9, 577–584, doi:10.3762/bjoc.9.62

• this paper we report a study of a reaction between dialkylaminonaphtho- and anthraquinones and sulfur monochloride in the presence of tertiary amines, a selective synthesis of fused thiazoles, and some of their chemical transformations. Results and Discussion We examined in detail the reaction of 2

• -[butyl(methyl)amino]naphthoquinone 3a with sulfur monochloride and tertiary amines [N-ethyldiisopropylamine (Hünig’s base) and 1,4-diazabicyclooctane (DABCO)]. Treatment of naphthoquinone 3a with S2Cl2 (9 equiv) and Hünig’s base (5 equiv) in THF at 0 °C for 72 h with subsequent heating under reflux for 2

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Synthesis and ring openings of cinnamate-derived N-unfunctionalised aziridines

• Alan Armstrong and
• Alexandra Ferguson

Beilstein J. Org. Chem. 2012, 8, 1747–1752, doi:10.3762/bjoc.8.199

• screen of alternative solvents, tertiary amines and bases showed that NMM and NaOH in CH2Cl2 was the optimum reagent combination for the aziridination. Having optimised our aziridination protocol for tert-butyl cinnamate, our attention then turned to examining the scope for aromatic substitution in the

Organocatalytic C–H activation reactions

• Subhas Chandra Pan

Beilstein J. Org. Chem. 2012, 8, 1374–1384, doi:10.3762/bjoc.8.159

• report by the Akiyama group is the predominant use of N,N-dibenzylamine as the amine donor in their reaction instead of cyclic tertiary amines as used by the Kim group. The present authors employed biphenyl-based chiral phosphoric acid catalysts 15a and 15b and moderate to high yields (45–95%) and

Organocatalytic asymmetric allylic amination of Morita–Baylis–Hillman carbonates of isatins

• Hang Zhang,
• Shan-Jun Zhang,
• Qing-Qing Zhou,
• Lin Dong and
• Ying-Chun Chen

Beilstein J. Org. Chem. 2012, 8, 1241–1245, doi:10.3762/bjoc.8.139

• isatins to obtain 2-oxindoles bearing a C3-quaternary chiral center, by the catalysis of chiral tertiary amines, β-isocupreidine (β-ICD) or its derivatives [23][24]. We envisaged that such a catalytic strategy should be applicable to the allylic amination of the corresponding MBH carbonates [25][26][27

• with N-benzyloxycarbonyl and O-benzyl groups [29] was applied in diethyl ether (Table 1, entry 1). Subsequently, an array of tertiary amines derived from quinidine was explored to introduce chirality into the product. While poor enantioselectivity was obtained when β-isocupreidine 1a (β-ICD) or β

Synthesis and photooxidation of styrene copolymer bearing camphorquinone pendant groups

• Branislav Husár,
• Norbert Moszner and
• Ivan Lukáč

Beilstein J. Org. Chem. 2012, 8, 337–343, doi:10.3762/bjoc.8.37

• (CQ) in the presence of H-atom donors such as ethers (H abstraction), or more efficiently tertiary amines (electron/proton transfer), is known to be an effective photoinitiator for curing methacrylate-based dental restorative resins [1][2][3][4][5][6][7][8][9]. CQ photochemistry in solution in the

Equilibrium constants and protonation site for N-methylbenzenesulfonamides

• José A. Moreira,
• Ana M. Rosa da Costa,
• Luis García-Río and
• Márcia Pessêgo

Beilstein J. Org. Chem. 2011, 7, 1732–1738, doi:10.3762/bjoc.7.203

• Hammett’s methodology is only applicable to similar classes of compounds [18][19]. In reality, during the 1950’s, a variety of acidity constants for different kinds of bases, such as tertiary amines (H0’’’) [20], amides (Ha) [21], carbinoles (HR+) [22], and indoles (HI) [23], among others [19][24], were

Reductive amination with zinc powder in aqueous media

• Giovanni B. Giovenzana,
• Daniela Imperio,
• Andrea Penoni and
• Giovanni Palmisano

Beilstein J. Org. Chem. 2011, 7, 1095–1099, doi:10.3762/bjoc.7.125

• phenolic hydroxy groups. The list illustrates the significant applicability of this one-pot zinc-mediated reductive amination. Nevertheless the protocol showed some limitations with selected substrates: i) Secondary amines failed to give tertiary amines; ii) hindered primary amines (e.g., tert-butylamine

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

• -alkylated amines in excellent yields (Scheme 21). Zeng and co-workers reported that cationic gold(I) complexes promote the addition of all types of non-tertiary amines 120 to a variety of allenes 121 to afford allylic amines 122 in good to excellent yields [58]. Importantly, the Markovnikov adduct was

Shelf-stable electrophilic trifluoromethylating reagents: A brief historical perspective

• Norio Shibata,
• Andrej Matsnev and
• Dominique Cahard

Beilstein J. Org. Chem. 2010, 6, No. 65, doi:10.3762/bjoc.6.65

• products in high yields. Primary and secondary amines also reacted with 20b to afford N-CF3 products in good yields. Tertiary amines as well as pyridines gave quaternary ammonium and pyridinium salts, respectively. Electrophilic trifluoromethylation could also be achieved by thermal decomposition of 2

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32