Synthesis of a tricyclic lactam via Beckmann rearrangement and ring-rearrangement metathesis as key steps

• Sambasivarao Kotha,
• Ongolu Ravikumar and
• Jadab Majhi

Beilstein J. Org. Chem. 2015, 11, 1503–1508, doi:10.3762/bjoc.11.163

• ; found, 224.1041. Retrosynthetic analysis of tricyclic amide 1. Molecular crystal structure of compound 11b. Synthesis of tricyclic ketone 4. Beckmann rearrangement of oximes 8a and 8b. Beckmann rearrangement reaction in a single step. Synthesis of ring-rearrangement precursors. Synthesis of Beckmann

Synthesis of icariin from kaempferol through regioselective methylation and para-Claisen–Cope rearrangement

• Qinggang Mei,
• Chun Wang,
• Zhigang Zhao,
• Weicheng Yuan and
• Guolin Zhang

Beilstein J. Org. Chem. 2015, 11, 1220–1225, doi:10.3762/bjoc.11.135

• [15]. The 11-step synthesis of icaritin, starting from 2,4,6-trihydroxyacetophenone via microwave-assisted Claisen rearrangement reaction as the key step, was succeeded with an overall yield of 23% [16]. In view of the long synthetic routes, tedious work-up and harsh reaction conditions, an

A facile synthesis of functionalized 7,8-diaza[5]helicenes through an oxidative ring-closure of 1,1’-binaphthalene-2,2’-diamines (BINAMs)

• Youhei Takeda,
• Masato Okazaki,
• Yoshiaki Maruoka and
• Satoshi Minakata

Beilstein J. Org. Chem. 2015, 11, 9–15, doi:10.3762/bjoc.11.2

• (Scheme 2, the upper reaction) [31]. During a thorough screening of oxidants for the rearrangement reaction, we found out that the use of tert-butyl hypochlorite (t-BuOCl) as an oxidant exclusively gave 7,8-diaza[5]helicene instead of the corresponding rearranged product in good yields. This preliminary

Superoxide chemistry revisited: synthesis of tetrachloro-substituted methylenenortricyclenes

• Basavaraj M. Budanur and
• Faiz Ahmed Khan

Beilstein J. Org. Chem. 2014, 10, 2531–2538, doi:10.3762/bjoc.10.264

• from a concurrent elimination as well as a rearrangement reaction. In superoxide chemistry many aprotic solvents have been used. We prefer DMSO because the solubility of potassium superoxide is better in DMSO compared to other solvents [16]. As the phase-transfer catalyst can enhance the extent of

Reaction of selected carbohydrate aldehydes with benzylmagnesium halides: benzyl versus o-tolyl rearrangement

• Maroš Bella,
• Bohumil Steiner,
• Vratislav Langer and
• Miroslav Koóš

Beilstein J. Org. Chem. 2014, 10, 1942–1950, doi:10.3762/bjoc.10.202

Macrocyclic bis(ureas) as ligands for anion complexation

• Claudia Kretschmer,
• Gertrud Dittmann and
• Johannes Beck

Beilstein J. Org. Chem. 2014, 10, 1834–1839, doi:10.3762/bjoc.10.193

• fragmentation and rearrangement reaction had occurred. Under the applied conditions 1 is completely converted to dihydroindoloquinolinone 3 (Scheme 2). In accordance with the effortlessness of the conversion reaction, the mass spectrum of 1 is dominated by the [M/2]+ signal. The indoloquinolinone 3 forms

Selective allylic hydroxylation of acyclic terpenoids by CYP154E1 from Thermobifida fusca YX

• Anna M. Bogazkaya,
• Clemens J. von Bühler,
• Sebastian Kriening,
• Alexandrine Busch,
• Alexander Seifert,
• Jürgen Pleiss,
• Sabine Laschat and
• Vlada B. Urlacher

Beilstein J. Org. Chem. 2014, 10, 1347–1353, doi:10.3762/bjoc.10.137

• oxidation, reduction, isomerisation or conjugation reactions [14]. Furthermore, in some bacteria assimilating terpenes as carbon sources, the first oxidation step is a P450-mediated allylic hydroxylation or allylic rearrangement reaction [15]. In vitro investigations demonstrated that P450 enzymes can

Theoretical studies on the intramolecular cyclization of 2,4,6-t-Bu₃C₆H₂P=C: and effects of conjugation between the P=C and aromatic moieties

• Masaaki Yoshifuji and
• Shigekazu Ito

Beilstein J. Org. Chem. 2014, 10, 1032–1036, doi:10.3762/bjoc.10.103

• , C4–C6 1.396, C6–C7 1.394 C7–C8 1.393, C8–C9 1.403, C3–C9 1.427. Bond angle and dihedral angles (°): C3–P1–C1 101.7, C1–P1–C3–C4 22.9, C1–P1–C3–C9 160.1. HOMO (left) and LUMO (right) of 2. (a) The original FBW rearrangement reaction and (b) the phosphorus version of FBW rearrangement. Intramolecular C

Silica sulfuric acid: a reusable solid catalyst for one pot synthesis of densely substituted pyrrole-fused isocoumarins under solvent-free conditions

• Sudipta Pathak,
• Kamalesh Debnath and
• Animesh Pramanik

Beilstein J. Org. Chem. 2013, 9, 2344–2353, doi:10.3762/bjoc.9.269

• the synthetic route ‘‘benign by design’’. This is the first report, in which a rearrangement reaction has been carried out on the solid surface of SSA. Overall this greener and environmentally friendly method may attract the fellow chemists in chemical and pharmaceutical industries for the synthesis

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

• (distonic ion) [106]. We have applied Ru(bpz)3(PF6)2-catalyzed photooxidation of N-cyclopropylanilines to induce this rearrangement reaction. The resulting distonic ion was then intercepted by alkenes to produce [3 + 2] annulation products (Scheme 32) [107]. An aryl group on the amine was required for the

The first example of the Fischer–Hepp type rearrangement in pyrimidines

• Inga Cikotiene,
• Mantas Jonusis and
• Virginija Jakubkiene

Beilstein J. Org. Chem. 2013, 9, 1819–1825, doi:10.3762/bjoc.9.212

• reaction we observed has a lot in common with the Fischer–Hepp rearrangement. However, hydrochloric and hydrobromic acids gave worse results in comparison to sulfuric acid. In order to shed some light on the reaction mechanism, we performed the rearrangement reaction of 4ea in the presence of 20

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

Isotopic labelling studies for a gold-catalysed skeletal rearrangement of alkynyl aziridines

• Paul W. Davies,
• Nicolas Martin and
• Neil Spencer

Beilstein J. Org. Chem. 2011, 7, 839–846, doi:10.3762/bjoc.7.96

• periodinane. Reaction of deuterated alkynyl aziridine 4 in the skeletal rearrangement reaction. Preparation of 13C-enriched alkynyl aziridines. Cycloisomerisation of 11 in the skeletal rearrangement reaction. Cycloisomerisation of 11 to give 2,5-disubstituted pyrrole. Cycloisomerisation of 14 in the skeletal

• rearrangement reaction. Cycloisomerisation of 15 in the skeletal rearrangement reaction. Revised mechanism for the formation of 2,4-isomers by skeletal rearrangement. Synthesis of alkynyl aziridines 30 and 31. Electronic effects on the outcome of the skeletal rearrangement processes. Mechanistic rationale for

Asymmetric synthesis of tertiary thiols and thioethers

• Jonathan Clayden and
• Paul MacLellan

Beilstein J. Org. Chem. 2011, 7, 582–595, doi:10.3762/bjoc.7.68

• with electrophiles is general for a range of structures, but until very recently it has not been applicable to arylation reactions. However, we have discovered [75] a variant of a rearrangement reaction of lithiated ureas that we first reported in 2007 [76] in which a lithiated thiocarbamate undergoes

An enantiomerically pure siderophore type ligand for the diastereoselective 1 : 1 complexation of lanthanide(III) ions

• Markus Albrecht,
• Olga Osetska,
• Thomas Abel,
• Gebhard Haberhauer and
• Eva Ziegler

Beilstein J. Org. Chem. 2009, 5, No. 78, doi:10.3762/bjoc.5.78

• enantiomerically pure “non-natural” peptide moiety [25], which organizes three tridenate metal binding sites in one direction [26][27][28]. The synthesis of the compound is facile and utilizes a multiple Claisen-rearrangement reaction as introduced by Hiratani as the keystep [29][30]. UV and CD titration

Synthesis of novel photochromic pyrans via palladium- mediated reactions

• Christoph Böttcher,
• Gehad Zeyat,
• Saleh A. Ahmed,
• Elisabeth Irran,
• Thorben Cordes,
• Cord Elsner,
• Wolfgang Zinth and
• Karola Rueck-Braun

Beilstein J. Org. Chem. 2009, 5, No. 25, doi:10.3762/bjoc.5.25

• ]. However, only the rearranged and hydrodehalogenated benzofuran 14 was isolated in 65% yield after flash chromatography. Formation of the benzofuran can be rationalized by cleavage of the benzopyran ring and a subsequent rearrangement reaction [29][30]. However, by using standard Sonogashira conditions in

Synthesis of crispine A analogues via an intramolecular Schmidt reaction

• Ajoy Kapat,
• Ponminor Senthil Kumar and
• Sundarababu Baskaran

Beilstein J. Org. Chem. 2007, 3, No. 49, doi:10.1186/1860-5397-3-49

• developed for the synthesis of crispine A. [20][21][22][23][24][25][26][27][28] Interestingly, Schell and Smith reported the first synthesis of crispine A, even before its isolation, using the N-chloramine rearrangement reaction as a key step.[25] In order to understand the structure activity relationship