Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

Vicinal ketoesters – key intermediates in the total synthesis of natural products

• Marc Paul Beller and
• Ulrich Koert

Beilstein J. Org. Chem. 2022, 18, 1236–1248, doi:10.3762/bjoc.18.129

• reactivity in their synthesis of (+)-awajanomycin (92), a marine natural product with a γ-lactone-δ-lactam core structure (Scheme 15) [30][31]. Key step was an asymmetric allylboration of diethyl mesoxalate (90a) with boronate 89, which was easily accessible through a Matteson homologation of dichloromethyl

• ]. Enantioselective aldol reaction using an α-ketoester in the synthesis of (−)-irofulven (87) [29]. Allylboration of a mesoxalic acid ester in the synthesis of (+)-awajanomycin (92) [30][31]. Condensation of a diamine with mesoxolate in the synthesis of (−)-aplaminal (96) [32]. Synthesis of mesoxalic ester amide 102

Stereodivergent approach in the protected glycal synthesis of L-vancosamine, L-saccharosamine, L-daunosamine and L-ristosamine involving a ring-closing metathesis step

• Pierre-Antoine Nocquet,
• Aurélie Macé,
• Frédéric Legros,
• Jacques Lebreton,
• Gilles Dujardin,
• Sylvain Collet,
• Arnaud Martel,
• Bertrand Carboni and
• François Carreaux

Beilstein J. Org. Chem. 2018, 14, 2949–2955, doi:10.3762/bjoc.14.274

• corresponding alkenes 13a,b in 90% and 63% yield, respectively, over two steps. Alternatively, we envisioned that, from the same α-substituted chiral aldehyde 5, compound 13b could be obtained in a more straightforward manner employing a strategy based on a diastereoselective allylboration reaction (Scheme 2

• metathesis of vinyl ethers as key step for the preparation of several carbamate-protected 3-aminoglycals. Evans aldol reaction for the preparation of diastereomeric compounds 13a and 13b. Alternative preparation of 13b based on a diastereoselective allylboration. O-Vinylation-ring-closing metathesis sequence

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

Boron-substituted 1,3-dienes and heterodienes as key elements in multicomponent processes

• Ludovic Eberlin,
• Fabien Tripoteau,
• François Carreaux,
• Andrew Whiting and
• Bertrand Carboni

Beilstein J. Org. Chem. 2014, 10, 237–250, doi:10.3762/bjoc.10.19

• tools in synthetic organic chemistry. The most significant recent results and developments obtained in this area are reported in this review. Keywords: allylboration; boron compounds; Diels–Alder; 1,3-dienes; multicomponent reactions; Petasis borono–Mannich; Suzuki couplings; Introduction

• described in 1972 by Mikhailov and co-workers [29], and it was only fifteen years later that the groups of Vaultier and Hoffmann highlighted the real potential of these compounds in tandem cycloaddition [4 + 2]/allylboration processes [30]. These dienes reacted with activated dienophiles, such as maleic

• /allylboration reactions [41]. In the case of the 4-methoxy-substituted diene, if the first step occurred at 80 °C in toluene, it was impossible to obtain the allylation products, even by heating at higher temperature or by activation with EtAlCl2. By contrast, with the 3-OTES derivative, bicyclic, three

Aryl nitrile oxide cycloaddition reactions in the presence of pinacol boronic acid ester

• Sarah L. Harding,
• Sebastian M. Marcuccio and
• G. Paul Savage

Beilstein J. Org. Chem. 2012, 8, 606–612, doi:10.3762/bjoc.8.67

• esters in organic synthesis is demonstrated by their use as key intermediates in transition-metal-catalysed bond-forming reactions [6], which include the Miyaura–Suzuki coupling reaction [7], copper-catalysed heteroatom arylation [8], allylboration [9], and the Petasis reaction [10]. Aryl boronic esters

Directed ortho,ortho'-dimetalation of hydrobenzoin: Rapid access to hydrobenzoin derivatives useful for asymmetric synthesis

• Inhee Cho,
• Labros Meimetis,
• Lee Belding,
• Michael J. Katz,
• Travis Dudding and
• Robert Britton

Beilstein J. Org. Chem. 2011, 7, 1315–1322, doi:10.3762/bjoc.7.154

• hydrobenzoin·SnCl4 complex 5 promotes the allylboration of hydrocinnamaldehyde with modest enantioselectivity (26% ee) [3], and a hydrobenzoin–ytterbium complex was found to catalyze asymmetric aldol/Evans–Tishchenko reactions [5]. Moreover, the hydrobenzoin dimethyl ether 7 was shown to direct the asymmetric

• parent diol 3 [3][14]. For example, the addition of cyclooctyl rings to the ortho and ortho' positions of the hydrobenzoin·SnCl4 complex (i.e., Vivol·SnCl4 (6)) leads to a dramatic improvement in enantioselectivity in the allylboration of hydrocinnamaldehyde (93% ee) [3]. Unfortunately, while (R,R)- and

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

An asymmetric synthesis of all stereoisomers of piclavines A1-4 using an iterative asymmetric dihydroxylation

• Yukako Saito,
• Naoki Okamoto and
• Hiroki Takahata

Beilstein J. Org. Chem. 2007, 3, No. 37, doi:10.1186/1860-5397-3-37

• challenge. Our interest in this field has been focused on potential strategies based on the enantiomeric enhancement caused by the twofold or more application of the Sharpless asymmetric dihydroxylation (AD) [5][6] or Brown's asymmetric allylboration[7] reactions. In general, the enantiomeric excesses (ees

Synthesis of 2,6-trans- disubstituted 5,6-dihydropyrans from (Z)-1,5-syn-endiols

• Eric M. Flamme and
• William R. Roush

Beilstein J. Org. Chem. 2005, 1, No. 7, doi:10.1186/1860-5397-1-7

• silylation of the allylic alcohol unit followed by mesylate formation and base-promoted nucleophilic displacement. Findings We recently reported a one-pot double allylboration reaction sequence which provides (Z)-1,5-syn-endiols from simple aldehyde starting materials with excellent diastereo- and