A convenient route to symmetrically and unsymmetrically substituted 3,5-diaryl-2,4,6-trimethylpyridines via Suzuki–Miyaura cross-coupling reaction

• Dariusz Błachut,
• Joanna Szawkało and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2016, 12, 835–845, doi:10.3762/bjoc.12.82

• valuable but unstable 2-formyl group gave again a low yield of product 24 (35%). Initially, our attempts to obtain pyridine 29 completely failed due to a very low solubility of 2-aminophenylboronic acid hydrochloride in toluene. The problem was overcome by addition of a small amount of water (approx 10 mol

Cross metathesis of unsaturated epoxides for the synthesis of polyfunctional building blocks

• Meriem K. Abderrezak,
• Kristýna Šichová,
• Nancy Dominguez-Boblett,
• Antoine Dupé,
• Zahia Kabouche,
• Christian Bruneau and
• Cédric Fischmeister

Beilstein J. Org. Chem. 2015, 11, 1876–1880, doi:10.3762/bjoc.11.201

• electron- deficient olefin cross metathesis partner has received attention for the synthesis of polymer precursors. For instance, we have reported the reduction of the nitrile functional group into primary amine [22] and the reduction of the formyl group into alcohol [23][24]. Herein, we focused on the

Development of variously functionalized nitrile oxides

• Haruyasu Asahara,
• Keita Arikiyo and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2015, 11, 1241–1245, doi:10.3762/bjoc.11.138

• -methylcarbamoyl group to an acyl or formyl group was achieved upon treatment with a Grignard reagent or with DIBAL (Table 3, entries 7 and 8). The chemical conversion of N-methylamides to versatile carbonyl functions was systematically studied. In this protocol, the tosyl group was found to be effective for the

The preparation of new functionalized [2.2]paracyclophane derivatives with N-containing functional groups

• Henning Hopf,
• Swaminathan Vijay Narayanan and
• Peter G. Jones

Beilstein J. Org. Chem. 2015, 11, 437–445, doi:10.3762/bjoc.11.50

• tetrahedral intermediate thus generated, the polyether bridge functions as a leaving group to form an aldehyde intermediate. This is subsequently reduced a second time to the N-CH3 moiety. In compound 22 one formyl group is still present whereas in 23 this has been lost completely. Both compounds were

Enantioselective synthesis of polyhydroxyindolizidinone and quinolizidinone derivatives from a common precursor

• Nemai Saha and
• Shital K. Chattopadhyay

Beilstein J. Org. Chem. 2014, 10, 3104–3110, doi:10.3762/bjoc.10.327

• oxidative cleavage of the vicinal diol unit in the latter to a formyl group (not isolated) followed by its in situ reduction with NaBH4 delivered the hydroxymethyl chain in 17. Hydrogenolytic removal of the two benzyl ether functionalities with Pearlman’s catalyst then afforded the tetrahydroxyindolizidine

Preparation of neuroprotective condensed 1,4-benzoxazepines by regio- and diastereoselective domino Knoevenagel–[1,5]-hydride shift cyclization reaction

• László Tóth,
• Yan Fu,
• Hai Yan Zhang,
• Attila Mándi,
• Katalin E. Kövér,
• Tünde-Zita Illyés,
• Attila Kiss-Szikszai,
• Balázs Balogh,
• Tibor Kurtán,
• Sándor Antus and
• Péter Mátyus

Beilstein J. Org. Chem. 2014, 10, 2594–2602, doi:10.3762/bjoc.10.272

• acid (13) and malononitrile (14) all containing active methylene groups, which initiated a domino reaction (Scheme 2). The Knoevenagel reaction of the formyl group in rac-5 and the active methylene groups of 12–14 afforded the intermediates rac-6a–c (Scheme 1), which underwent regioselective [1,5

The regulation and biosynthesis of antimycins

• Ryan F. Seipke and
• Matthew I. Hutchings

Beilstein J. Org. Chem. 2013, 9, 2556–2563, doi:10.3762/bjoc.9.290

• utilise acyl-SNACs provides the possibility to employ feeding studies to introduce new chemistry at C-8. AntO is a lipase homologue and is predicted to install the N-formyl group resulting in the 3-formamidosalicylate moiety. AntO is required for bioactivity against the human pathogenic fungus, Candida

• albicans (Seipke and Hutchings, unpublished results), but the exact time in which AntO installs the N-formyl group is unclear and requires investigation. Regulation of the ant gene cluster Antimycin biosynthesis is linked to development, as is the case for many Streptomyces secondary metabolites. However

The chemistry of isoindole natural products

• Klaus Speck and
• Thomas Magauer

Beilstein J. Org. Chem. 2013, 9, 2048–2078, doi:10.3762/bjoc.9.243

• prenyl side chain and introduction of the formyl group was accomplished within five steps to give 191a (Scheme 25). The envisioned deprotection of 191a using Lewis acidic conditions led to an unexpected and unprecedented metal-free carbonyl–olefin metathesis. Coordination of boron trifluoride etherate to

Formal synthesis of (−)-agelastatin A: an iron(II)-mediated cyclization strategy

• Daisuke Shigeoka,
• Takuma Kamon and
• Takehiko Yoshimitsu

Beilstein J. Org. Chem. 2013, 9, 860–865, doi:10.3762/bjoc.9.99

• significant [42]. Various yields of 9 obtained by loading consistent amounts (1.2–1.5 equiv) of Bu4NX salts also indicated the poor contribution of the pathway. Chan and co-workers demonstrated that an iron–imido complex generated from FeCl2/PhI=NTs underwent radical hydrogen abstraction from a formyl group

Bioactive selaginellins from Selaginella tamariscina (Beauv.) Spring

• Chao Yang,
• Yutian Shao,
• Kang Li and
• Wujiong Xia

Beilstein J. Org. Chem. 2012, 8, 1884–1889, doi:10.3762/bjoc.8.217

• ). The assignment of all 1H and 13C NMR data (shown in Table 1) was confirmed by 2D NMR techniques. The NMR spectra of 1 showed the typical signals of a formyl group (δH 10.73 and δC 190.9), an alkynyl band (δC 82.4, 101.0), three phenolic hydroxyl (δH 8.94 and 8.59), and five aromatic rings, including

• E-ring, and one ABMN system (δH 7.61, 7.42, 6.41 and 6.35, each 1H, d, J = 10.0 Hz) for the C-ring. The above structural features suggested 1 was a selaginellin with a formyl group. Key evidence for the structure of 1 obtained from the HMBC experiment further confirmed this suggestion (Figure 2

• ). The HMBC correlations H16/C-26 and H-26/C-15 concluded the substitution of the formyl group at C-15 of the A-ring. The alkynyl group was connected to the B-ring based on correlations between H-29,33 and C-28. The linkage between the C-ring and the B-ring was located at C-7 demonstrated by the HMBC

Stereoselective synthesis of trans-fused iridoid lactones and their identification in the parasitoid wasp Alloxysta victrix, Part I: Dihydronepetalactones

• Nicole Zimmermann,
• Robert Hilgraf,
• Lutz Lehmann,
• Daniel Ibarra and
• Wittko Francke

Beilstein J. Org. Chem. 2012, 8, 1246–1255, doi:10.3762/bjoc.8.140

• steric strain. Due to the CH-acidity at the α-position of the formyl group, epimerization of the all-trans product 24 under acidic or basic conditions could be expected. Lange et al. reported the catalytic hydrogenation of a structurally close analogue, (5R)-1-formyl-2-methyl-5-isopropylcyclopent-1-ene

The effect of the formyl group position upon asymmetric isomeric diarylethenes bearing a naphthalene moiety

• Renjie Wang,
• Shouzhi Pu,
• Gang Liu and
• Shiqiang Cui

Beilstein J. Org. Chem. 2012, 8, 1018–1026, doi:10.3762/bjoc.8.114

• Renjie Wang Shouzhi Pu Gang Liu Shiqiang Cui Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science & Technology Normal University, Nanchang 330013, PR China 10.3762/bjoc.8.114 Abstract Three new isomeric asymmetric diarylethenes with a naphthyl moiety and a formyl group at the para, meta

• or ortho position of the terminal benzene ring were synthesized. Their photochromism, fluorescent-switch, and electrochemical properties were investigated. Among these diarylethenes, the one with a formyl group at the ortho position of benzene displayed the largest molar absorption coefficients and

• solution and PMMA films. Cyclic voltammograms proved that the formyl group and its position could effectively modulate the electrochemical behaviors of these diarylethene derivatives. Keywords: chemical diversity; diarylethene; electrochemistry; formyl group; photochromism; substituent position effect

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

• intermediate leading to the tautomeric formyl group. Thermochemical computations at M06-2X/cc-pVDZ in conjunction with a self-consistent solvent reaction field model support this suggested reaction pathway. Keywords: benzofuran; C–H-insertion; hydroxycarbene; singlet carbene; tunneling; Introduction

Redox-active tetrathiafulvalene and dithiolene compounds derived from allylic 1,4-diol rearrangement products of disubstituted 1,3-dithiole derivatives

• Filipe Vilela,
• Peter J. Skabara,
• Christopher R. Mason,
• Thomas D. J. Westgate,
• Asun Luquin,
• Simon J. Coles and
• Michael B. Hursthouse

Beilstein J. Org. Chem. 2010, 6, 1002–1014, doi:10.3762/bjoc.6.113

• hindrance by the aromatic units towards the formyl group, compound 21 [4] was reacted with ethylenediamine in the presence of a catalytic amount of acetic acid (Scheme 5). The Schiff base product 22 was obtained in 62% yield as a pale brown crystalline solid. Although highly strained and buckled TTF

Preparation and NMR spectra of four isomeric diformyl[2.2]paracyclophanes (cyclophanes 66)

• Ina Dix,
• Henning Hopf,
• Thota B. N. Satyanarayana and
• Ludger Ernst

Beilstein J. Org. Chem. 2010, 6, 932–937, doi:10.3762/bjoc.6.104

• assumption is justified, as it is difficult to judge whether steric and/or electronic substituent interactions could cause significant deviations from SCS additivity. Furthermore, the SCSs exerted by the formyl group upon the nuclei of the distant ring are relatively small, |ΔδH| < 0.11 ppm, |ΔδC| < 0.88 ppm

• = 3.11 ppm experiences a strong NOE when the resonance of 5-H (ortho to the 4-CHO group) is saturated, and vice versa. Its coupling constants show that the 3.11 ppm multiplet belongs to 9-Hs (cis to the deshielded proton 10-Hs, which itself is syn to the second formyl group, see Scheme 3). This proves

Bis(oxazolines) based on glycopyranosides – steric, configurational and conformational influences on stereoselectivity

• Tobias Minuth and
• Mike M. K. Boysen

Beilstein J. Org. Chem. 2010, 6, No. 23, doi:10.3762/bjoc.6.23

• a corresponding ligand with a formyl group as the smallest possible acyl residue at the 3-O-position. In this paper we describe the synthesis of new 3-epimerised and 3-deoxygenated carbohydrate bis(oxazolines), the preparation of a 3-O-formate analogue of ligands 3 as well as the testing of these

Synthesis of some novel annulated pyrido[2,3-d]pyrimidines via stereoselective intramolecular hetero Diels–Alder reactions of 1-oxa-1,3-butadienes

• Mohit L. Deb and
• Pulak J. Bhuyan

Beilstein J. Org. Chem. 2010, 6, No. 11, doi:10.3762/bjoc.6.11

• lone pair on the allyl nitrogen through the formyl group which makes it less electrophilic towards the active methylene compounds. However, the use of a stronger base, e.g. N,N-diisopropylethylamine (DIPEA) under refluxing conditions in ethanol for 3 h gave quite satisfactory results in all cases. In

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

• give compound 194. The allyl group was cleaved using nickel chloride and triethylaluminium and fragmentation with iodosobenzene and iodine afforded compound 195. The formyl group was hydrolyzed and the azide was introduced using diphenylphosphoryl azide (DPPA) to give 187. The azide 189 was then