Thioester derivatives of the natural product psammaplin A as potent histone deacetylase inhibitors

• Matthias G. J. Baud,
• Thomas Leiser,
• Vanessa Petrucci,
• Mekala Gunaratnam,
• Stephen Neidle,
• Franz-Josef Meyer-Almes and
• Matthew J. Fuchter

Beilstein J. Org. Chem. 2013, 9, 81–88, doi:10.3762/bjoc.9.11

• explanations could be envisaged to explain this result: (1) The thioester is stable to the assay buffer and therefore does not contribute to the in situ generation of the free thiol. (2) The quantity of free thiol generated in situ in this experiment was too low to be quantified. An alternative hypothesis for

Flow photochemistry: Old light through new windows

• Jonathan P. Knowles,
• Luke D. Elliott and
• Kevin I. Booker-Milburn

Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229

N-Heterocyclic carbene-catalyzed direct cross-aza-benzoin reaction: Efficient synthesis of α-amino-β-keto esters

• Takuya Uno,
• Yusuke Kobayashi and
• Yoshiji Takemoto

Beilstein J. Org. Chem. 2012, 8, 1499–1504, doi:10.3762/bjoc.8.169

• employing the imines directly has rarely been developed [40][42], due to the unproductive reaction of NHCs with the imines. Therefore, in situ generation of imines or iminium ions from their precursors is generally required to control their reactivity. We anticipated that the introduction of appropriate

Synthesis of new pyrrole–pyridine-based ligands using an in situ Suzuki coupling method

• Matthias Böttger,
• Björn Wiegmann,
• Steffen Schaumburg,
• Peter G. Jones,
• Wolfgang Kowalsky and
• Hans-Hermann Johannes

Beilstein J. Org. Chem. 2012, 8, 1037–1047, doi:10.3762/bjoc.8.116

• ; in situ generation; pyrrole-pyridine; Suzuki coupling; Introduction Tridentate ligands have recently received attention in the area of rare-earth-metal complex chemistry [1][2][3][4][5]. Many rare-earth-metal cations, such as europium(III), have the tendency to be nine-coordinating species. Besides

Hybrid super electron donors – preparation and reactivity

• Jean Garnier,
• Douglas W. Thomson,
• Shengze Zhou,
• Phillip I. Jolly,
• Leonard E. A. Berlouis and
• John A. Murphy

Beilstein J. Org. Chem. 2012, 8, 994–1002, doi:10.3762/bjoc.8.112

• donor as 4, while the transfer of the second electron occurs at a more negative potential than for the first electron from 1. In situ generation of 9 from 20 (1.5 equiv, Scheme 3) and reaction with iodoarenes 28 and 30 was again carried out at room temperature. As for the reactions with donor 11, the

Efficient oxidation of oleanolic acid derivatives using magnesium bis(monoperoxyphthalate) hexahydrate (MMPP): A convenient 2-step procedure towards 12-oxo-28-carboxylic acid derivatives

• Jorge A. R. Salvador,
• Vânia M. Moreira,
• Rui M. A. Pinto,
• Ana S. Leal and
• José A. Paixão

Beilstein J. Org. Chem. 2012, 8, 164–169, doi:10.3762/bjoc.8.17

• -carboxylic acid 11 was obtained, in 85% yield, after the typical work-up procedure [18]. The formation of compound 11 from the 12α-hydroxy-28,13β-olide 2 is likely to occur due to the in situ generation of a Brønsted acid species from bismuth(III) triflate, which promotes ring opening of the 28,13β-olide

A general and facile one-pot process of isothiocyanates from amines under aqueous conditions

• Nan Sun,
• Bin Li,
• Jianping Shao,
• Weimin Mo,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2012, 8, 61–70, doi:10.3762/bjoc.8.6

• Academy of Sciences, Lanzhou 730000, China 10.3762/bjoc.8.6 Abstract A general and facile one-pot protocol for the preparation of a broad range of alkyl and aryl isothiocyanates has been developed from their corresponding primary amines under aqueous conditions. This synthetic process involves an in situ

• generation of a dithiocarbamate salt from the amine substrate by reacting with CS2 followed by elimination to form the isothiocyanate product with cyanuric acid as the desulfurylation reagent. The choice of solvent is of decisive importance for the successful formation of the dithiocarbamate salt

Amines as key building blocks in Pd-assisted multicomponent processes

• Didier Bouyssi,
• Nuno Monteiro and
• Geneviève Balme

Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163

• particularly alkynones. In situ generation of the latter is an interesting means of overcoming the poor commercial availability of these compounds and also offers the flexibility needed for library production (Scheme 15). Thus various (hetero)aryl acid chlorides and terminal alkynes were heated in THF in the

PEG-embedded KBr₃: A recyclable catalyst for multicomponent coupling reaction for the efficient synthesis of functionalized piperidines

• Sanny Verma,
• Suman L. Jain and
• Bir Sain

Beilstein J. Org. Chem. 2011, 7, 1334–1341, doi:10.3762/bjoc.7.157

• , safer handling and efficient recycling of the catalyst make this more suitable and preferable than the existing organic ammonium tribromides [30][31]. The mechanism of this reaction is not clear at this stage, however, the reaction probably involves the in situ generation of HBr in the presence of

• reaction mixture by UV–vis spectroscopy at the end of the reaction; no bromine was detected in the reaction mixture, thus establishing the in situ generation of bromine from the reagent during the reaction. Conclusion In summary, we have described the first time use of inexpensive, environmentally benign

• bromine could be detected in the reaction mixture as analyzed by UV−vis spectroscopy; this established the in situ generation of bromine from the reagent during the reaction. Typical experimental procedure Into a stirred mixture of aniline (0.2 g, 2.15 mmol), benzaldehyde (0.2 g, 1.89 mmol), ethyl

Functionalization of heterocyclic compounds using polyfunctional magnesium and zinc reagents

• Paul Knochel,
• Matthias A. Schade,
• Sebastian Bernhardt,
• Georg Manolikakes,
• Albrecht Metzger,
• Fabian M. Piller,
• Christoph J. Rohbogner and
• Marc Mosrin

Beilstein J. Org. Chem. 2011, 7, 1261–1277, doi:10.3762/bjoc.7.147

• -catalyzed cross-coupling of benzylic zinc reagent 34 with ethyl 2-chloronicotinate. In situ generation of arylzinc reagents using Mg in the presence of LiCl and ZnCl2. Zincation of heterocycles with TMP2Zn (42). Preparation of highly functionalized zincated heterocycles using TMP2Zn·2MgCl2·2LiCl (42

Intramolecular hydroxycarbene C–H-insertion: The curious case of (o-methoxyphenyl)hydroxycarbene

• Dennis Gerbig,
• David Ley,
• Hans Peter Reisenauer and
• Peter R. Schreiner

Beilstein J. Org. Chem. 2010, 6, 1061–1069, doi:10.3762/bjoc.6.121

• . Hence, the general reactivity pattern of 5 under HVFP conditions is similar to that of other hetereocarbenes. However, synthetic access to substituted 2,3-dihydrobenzofuran derivatives through the in situ generation of various (o-methoxyphenyl)hydroxycarbenes from (o-methoxyphenyl)glyoxylic acids in

CAAC Boranes. Synthesis and characterization of cyclic (alkyl) (amino) carbene borane complexes from BF₃ and BH₃

• Julien Monot,
• Louis Fensterbank,
• Max Malacria,
• Emmanuel Lacôte,
• Steven J. Geib and
• Dennis P. Curran

Beilstein J. Org. Chem. 2010, 6, 709–712, doi:10.3762/bjoc.6.82

• (top) and 3b (bottom). Synthesis of stable CAAC–BF3 complexes 3a and 3b and in situ generation of CAAC–BH3 complex 4a. Supporting Information Supporting Information File 118: Procedures and characterization of the new complexes. Supporting Information File 119: Cif file of crystal structure of

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

• -(trifluoromethoxy)biphenylyl-2′-diazonium salts such as 19a (R=H) through in situ generation of a trifluoromethyloxonium salt. The yield of trifluoromethylated products was highly dependent on the counteranion as observed in the trifluoromethylation of phenol (Scheme 17) [23]. The synthetic application of thermally

Synthesis of oxa-bridged derivatives from Diels–Alder bis-adducts of butadiene and 1,2,3,4-tetrahalo-5,5-dimethoxycyclopentadiene

• Faiz Ahmed Khan and
• Karuppasamy Parasuraman

Beilstein J. Org. Chem. 2010, 6, No. 64, doi:10.3762/bjoc.6.64

• derivatives; ruthenium; 3-sulfolene; Introduction 3-Sulfolene is a nonflammable, nontoxic, nonhygroscopic and stable crystalline solid and is a convenient equivalent for gaseous 1,3-butadiene [1][2][3] and is commonly used for in situ generation of 1,3-butadiene as the diene component in Diels–Alder

One-pot three-component synthesis of quinoxaline and phenazine ring systems using Fischer carbene complexes

• Priyabrata Roy and
• Binay Krishna Ghorai

Beilstein J. Org. Chem. 2010, 6, No. 52, doi:10.3762/bjoc.6.52

• trapped through Diels–Alder reaction with dienophiles leading to the synthesis of nitrogen containing heterocyclic analogues of quinoxaline and phenazine, respectively, in one-pot. This is the first report of in situ generation of furo[3,4-b]pyrazine intermediates. Synthetic plan towards quinoxaline

Controlling hazardous chemicals in microreactors: Synthesis with iodine azide

• Johan C. Brandt and
• Thomas Wirth

Beilstein J. Org. Chem. 2009, 5, No. 30, doi:10.3762/bjoc.5.30

• stable carbamoyl azides 4 as shown in Scheme 1. As sodium azide is poorly soluble in organic solvents, we decided to use tetrabutylammonium azide for the in situ generation of iodine azide. The reaction with iodine monochloride is rapid and after several minutes (depending on the flow rate) the aldehyde

• , 2H, H-12), 0.95 (t, 3JHH = 7.4 Hz, 3H, H-13) ppm; 13C NMR (125 MHz, CDCl3): δ 171.3 (C-8), 137.9 (C-5), 129.0 (C1/C-3), 124.2 (C-2), 119.7 (C-4/C-6), 37.6 (C-10), 27.7 (C-11), 22.4 (C-12), 13.8 (C-13) ppm. Microreactor setup for the in situ generation and use of iodine azide (IN3). Azide addition to

Ru-catalyzed dehydrogenative coupling of carboxylic acids and silanes - a new method for the preparation of silyl ester

• Guo-Bin Liu and
• Hong-Yun Zhao

Beilstein J. Org. Chem. 2008, 4, No. 27, doi:10.3762/bjoc.4.27

• )3Cl [46] and promoted by organocatalyst such as triphenylphosphine [47]. Generally, catalysts such as transition metals are expensive. [CuH(Ph3P)] requires a multiple-step synthetic approach and in-situ generation protocols. Results and Discussion In this communication, we wish to report the first

Vinylogous Mukaiyama aldol reactions with 4-oxy-2-trimethylsilyloxypyrroles: relevance to castanospermine synthesis

• Roger Hunter,
• Sophie C. M. Rees-Jones and
• Hong Su

Beilstein J. Org. Chem. 2007, 3, No. 38, doi:10.1186/1860-5397-3-38

• resulted in us developing a one-pot methodology involving its in situ generation. We have recently demonstrated the applicability of N-protected-4-methoxy-2-trimethylsilyloxy pyrroles 5 to the synthesis of key intermediates for the alkaloids lepadiformine [10] and castanospermine [11] using vinylogous