Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

• -Breslow-type intermediates with the chiral NHC-catalyst and subsequent deprotonation toward the nitrile product. Zhang, Wang, Ye, and co-workers utilized NHC-catalysis for the atroposelective synthesis of axially chiral diaryl ethers 59 and 61 [38]. This transformation was realized via desymmetrization of

• prochiral 2-aryloxyisophthalaldehydes 57a,b with a range of aliphatic and aromatic alcohols 58a–g, as well as heteroaromatic amines 60 (Scheme 19). Chiral diaryl ethers of this type received increased attention lately. Biju, Gao, Zhang, and Zeng groups all reported high degrees of yields and

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• ) to iodine(I). Intermediate II then undergoes an intramolecular aryl migration, yielding the diarylated products 41, analogous to the known iodoniumphenolate reactions that produce diaryl ethers. The same research group meliorated the N-arylation of aliphatic cyclic amines with the same fluorinated

• reaction that results in the formation of diaryl ethers. Diaryl ethers are important structural motifs in pharmaceuticals and agrochemicals due to their diverse biological activities. Since the 1950s, one of the most used methods for the synthesis of diaryl ethers involves the reaction of phenol with

• . A synthetic protocol for diaryl ethers via an in situ generation of a hypervalent iodine salt was introduced by Stuart and co-workers in 2020. To study the scope of the reaction first various substituted aryl(TMP)iodonium salts 12 were reacted with different substituted phenols 61 in the presence of

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• ” (macrocyclic diaryl ethers) series found in plants present on the African and Asian continent [15]. The first report of this class of compounds was made by Pettit and co-workers when they isolated combretastatin D-1 (1) from a CH2Cl2/MeOH extract of Combretum caffrum, a South African tree [16]. From 77 kg of

Synthesis of six-membered silacycles by borane-catalyzed double sila-Friedel–Crafts reaction

• Yafang Dong,
• Masahiko Sakai,
• Kazuto Fuji,
• Kohei Sekine and
• Yoichiro Kuninobu

Beilstein J. Org. Chem. 2020, 16, 409–414, doi:10.3762/bjoc.16.39

• , Fukuoka 816-8580, Japan 10.3762/bjoc.16.39 Abstract We have developed a catalytic synthetic method to prepare phenoxasilins. A borane-catalyzed double sila-Friedel–Crafts reaction between amino group-containing diaryl ethers and dihydrosilanes can be used to prepare a variety of phenoxasilin derivatives

• ][6][7][8][9][10], and reagents [11][12][13][14]. Therefore, the development of new methods to construct silacyclic skeletons is highly desirable. These compounds are commonly synthesized upon the reaction of heteroatom-bridged dilithiated diaryl compounds, such as dilithiated diaryl ethers and

• benzosiloles [39]. We have also contributed to the synthesis of silafluorenes from biphenyls and dihydrosilanes using a borane-catalyzed double sila-Friedel–Crafts reaction [40][41]. Subsequently, we envisaged that the catalytic reaction between diaryl ethers and dihydrosilanes may be a useful protocol to

Metal-free formal synthesis of phenoxazine

• Gabriella Kervefors,
• Antonia Becker,
• Chandan Dey and
• Berit Olofsson

Beilstein J. Org. Chem. 2018, 14, 1491–1497, doi:10.3762/bjoc.14.126

• recently, Bolm and co-workers reported a metal-free cyclization of iodo-substituted diaryl ethers with a broad scope (Scheme 1b) [18]. Transition metal-catalyzed cross couplings have also been employed to form the required C–O and C–N bonds, e.g., by Cu-catalyzed cyclization of 2-(2-bromophenoxy)anilines

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• also converted into the corresponding phenols in excellent yields. Notably, they claimed that hydroxy salt was indispensable for the conversion as a replacement of KOH with K3PO4 afforded 99% yield of diaryl ethers. Interestingly, the following work developed by the Kwong group in 2007 employed K3PO4

New depsidones and isoindolinones from the mangrove endophytic fungus Meyerozyma guilliermondii (HZ-Y₂) isolated from the South China Sea

• Senhua Chen,
• Zhaoming Liu,
• Yayue Liu,
• Yongjun Lu,
• Lei He and
• Zhigang She

Beilstein J. Org. Chem. 2015, 11, 1187–1193, doi:10.3762/bjoc.11.133

• ; Meyerozyma guilliermondii; Introduction Depsidones are characterized by the presence of cyclic diaryl ethers with an ester link joining the two aromatic rings [1][2]. They have been isolated mainly from various lichens [3][4][5] and other fungi [6][7][8][9][10][11]. These metabolites displayed a wide range

Total synthesis of ochnaflavone

• Monica M. Ndoile and
• Fanie R. van Heerden

Beilstein J. Org. Chem. 2013, 9, 1346–1351, doi:10.3762/bjoc.9.152

• synthesis of 1 would be to start with the preparation of a diaryl ether. This functionality is present in many important bioactive natural compounds [19] and it is not surprising that a great amount of effort has been focused on the development and improvement of the methods to form diaryl ethers [20][21

• ]. The Ullman reaction is often used to prepare diaryl ethers, but this reaction has the disadvantages of high reaction temperatures and intolerance to a wide variety of functional groups, with the major weakness being the inconsistency in the products obtained by the use of different copper sources [22

Screening of ligands for the Ullmann synthesis of electron-rich diaryl ethers

• Nicola Otto and
• Till Opatz

Beilstein J. Org. Chem. 2012, 8, 1105–1111, doi:10.3762/bjoc.8.122

• formation; diaryl ethers; nucleophilic aromatic substitution; Ullmann-type coupling; Introduction The diaryl ether linkage is a common structural motif encountered in numerous classes of natural products. Moreover, various diaryl ethers have been shown to possess antibacterial, anti-inflammatory

• tetramethylmagnolamine [6], and the antifungal diamine piperazinomycin [7] (Figure 1). A straightforward method for the formation of diaryl ethers is the Cu-catalyzed coupling of aryl halides with phenols, first reported by Fritz Ullmann in 1903 [8][9]. However, the classical protocol suffers from considerable

• to other classes of multidentate ligands. L48 also proved to possess a high catalytic activity, which is consistent with the results reported by Beller et al. [32] who used the ligand for the synthesis of various diaryl ethers. In the short-term screening, none of the tested ligands showed a higher

Translation of microwave methodology to continuous flow for the efficient synthesis of diaryl ethers via a base-mediated S_NAr reaction

• Charlotte Wiles and
• Paul Watts

Beilstein J. Org. Chem. 2011, 7, 1360–1371, doi:10.3762/bjoc.7.160

• ® S1) was employed for the continuous flow synthesis of diaryl ethers at 195 °C and 25 bar, affording a reduction in reaction time from tens of minutes to 60 s when compared with a stopped-flow microwave reactor. Keywords: automated synthesis; continuous flow; microreactor; microwave; nucleophilic

• substitution; organic bases; Introduction Diaryl ethers are a synthetically interesting subunit [1], with examples found in a series of medicinally significant natural products, such as (−)-K-13 (1) [2], riccardin C (2) [3] and combretastatins [4], along with synthetic herbicides, such as RH6201 (3) [5

• reaction of chloroarenes to a series of para-substituted phenols to afford a general and efficient route to the diaryl ether subunit. Results and Discussion With the optimised conditions from Marafie and Moseley’s [15] stopped-flow investigation taken as a starting point, the synthesis of diaryl ethers

Carbamate-directed benzylic lithiation for the diastereo- and enantioselective synthesis of diaryl ether atropisomers

• Abigail Page and
• Jonathan Clayden

Beilstein J. Org. Chem. 2011, 7, 1327–1333, doi:10.3762/bjoc.7.156

• Abigail Page Jonathan Clayden School of Chemistry, University of Manchester, Oxford Rd., Manchester M13 9PL, UK 10.3762/bjoc.7.156 Abstract Diaryl ethers carrying carbamoyloxymethyl groups may be desymmetrised enantio- and diastereoselectively by the use of the sec-BuLi–(−)-sparteine complex in

• on the enantioselective synthesis of diaryl ethers (a potential new class of chiral ligand having a structure related to the wide bite angle diphosphine DPEPhos) by biocatalytic oxidation or reduction, and which made use of desymmetrisation of a “pro-atropisomeric” substrate 4 to achieve the required

• enantiomeric enrichment in the product 5 [22]. In this paper we report parallel studies on the attempted asymmetric synthesis of atropisomeric diaryl ethers in diastereomerically and/or enantiomerically enriched form by the directed deprotonation and electrophilic quench of benzylic positions ortho to a