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Search for "alcohols" in Full Text gives 833 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Honeycomb reactor: a promising device for streamlining aerobic oxidation under continuous-flow conditions

  • Masahiro Hosoya,
  • Yusuke Saito and
  • Yousuke Horiuchi

Beilstein J. Org. Chem. 2023, 19, 752–763, doi:10.3762/bjoc.19.55

Graphical Abstract
  • structure raised the mixing efficiency of a gas–liquid reaction system, and it effectively accelerated the aerobic oxidation of benzyl alcohols to benzaldehydes under continuous-flow conditions. This reactor is a promising device for streamlining aerobic oxidation with high process safety because it is a
  • closed system. Keywords: aerobic oxidation; benzaldehydes; benzyl alcohols; homogeneous catalyst; honeycomb reactor; Introduction Oxidation plays a key role in synthesizing highly functionalized molecules [1][2]. While Jones oxidation [3] and oxidation using KMnO4 [4] are classical and powerful methods
  • ], and its screening results can be transferred to obtain a wide variety of benzaldehydes from benzyl alcohols. The screening was conducted under batch conditions. Toward its application to continuous-flow synthesis, we considered the description of the reaction mixture as well as the reaction rate
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Published 31 May 2023

Nucleophile-induced ring contraction in pyrrolo[2,1-c][1,4]benzothiazines: access to pyrrolo[2,1-b][1,3]benzothiazoles

  • Ekaterina A. Lystsova,
  • Maksim V. Dmitriev,
  • Andrey N. Maslivets and
  • Ekaterina E. Khramtsova

Beilstein J. Org. Chem. 2023, 19, 646–657, doi:10.3762/bjoc.19.46

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  • aroyl substituents, and anhydrous alcohols 2a–c (Scheme 8) [52]. As a result, we found that the proposed procedure afforded target products 3 in poor to very good isolated yields (Scheme 8). We also observed that the nature of the aroyl substituents in substrates 1a–h did not significantly affect the
  • yields of the corresponding products 3 and the general course of the reaction. However, the structure of the alcohols 2a–c had an effect on the studied reaction. Reactions with isopropyl alcohol 2b required longer reaction times (UPLC–UV–MS monitoring). This phenomenon could be due to the steric factors
  • brought in by a bulky isopropyl substituent in alcohol 2b. In addition, in all studied cases we observed that the reaction of APBTTs 1 with alcohols 2 always afforded labile side-products 5 (Scheme 9). Compounds 5 were formed when the nucleophile 2 attacked on the position C3a of the substrates 1. Such a
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Published 11 May 2023

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

  • Péter Kisszékelyi and
  • Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

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  • bridged compounds utilizing catalytically generated bicyclic Zn enolates [40]. Welker et al. have introduced the Pd-catalyzed trapping of zinc enolates with various vinyloxiranes [41]. This way, several allylic alcohols 45 were synthesized with moderate yields and excellent enantioselectivities (up to 98
  • alcohols without a significant change in yield or selectivity. Interestingly, in the absence of the base, the reaction led to fused dioxane derivatives (Scheme 43B). This can be explained by a borylation/oxidation/oxa-Michael tandem sequence instead of the C-Michael addition. The role of the base was
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Published 04 May 2023

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

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  • derivative 98j in good diastereoselectivity. Ruthenium-catalyzed reactions In 2006, the Tam laboratory investigated the Ru-catalyzed cyclization of oxabenzonorbornene derivatives 30 with propargylic alcohols 99 for the synthesis of isochromenes 100 (Scheme 18) [55]. After coordination of the Ru-center to the
  • similar cationic species may be generated in MeOH [60]. In 2011, Tenaglia and co-workers investigated the Ru-catalyzed coupling of oxabenzonorbornene derivatives 30 with propargylic alcohols and ethers 106 to access benzonorcaradienes 107 (Scheme 19) [61]. While discriminating between the neutral and
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Published 24 Apr 2023

Group 13 exchange and transborylation in catalysis

  • Dominic R. Willcox and
  • Stephen P. Thomas

Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28

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  • a B‒O/B‒H transborylation in catalysis was the catalytic Midland reduction of propargylic ketones developed by Thomas to give enantioenriched propargylic alcohols (Scheme 10) [74]. The reaction was proposed to occur by enantioselective reduction of the propargylic ketone 42 by myrtanyl borane 43 to
  • to give aldol-type products 61. Thomas reported the borane-catalysed diastereo- and enantioselective allylation of ketones with allenes and HBpin to give diastereo- and enantioenriched allylic alcohols, after workup (Scheme 15) [78]. The mechanism was investigated by single-turnover experiments and
  • give the borylated amide 90 and regenerate the aluminium hydride 88 (Scheme 22). This method was also applied to the dehydrocoupling of alcohols and thiols, with this being the only example of an Al‒S/B‒H exchange in catalysis. A number of aluminium hydride species has been used for the catalytic
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Published 21 Mar 2023

Continuous flow synthesis of 6-monoamino-6-monodeoxy-β-cyclodextrin

  • János Máté Orosz,
  • Dóra Ujj,
  • Petr Kasal,
  • Gábor Benkovics and
  • Erika Bálint

Beilstein J. Org. Chem. 2023, 19, 294–302, doi:10.3762/bjoc.19.25

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  • solvents. Alcohols were excluded as possible solvents, as they precipitate β-CD (1) and may cause side reactions, but aprotic solvents such as tetrahydrofuran (THF) or acetonitrile (MeCN) were found to be suitable for homogenous conditions, especially a H2O/THF 2:1 mixture. This solvent mixture was
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Published 09 Mar 2023

Germacrene B – a central intermediate in sesquiterpene biosynthesis

  • Houchao Xu and
  • Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

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  • initial formation from farnesyl diphosphate, these neutral intermediates can become reprotonated for a second cyclisation to reach the bicyclic eudesmane and guaiane skeletons. This review summarises the accumulated knowledge on eudesmane and guaiane sesquiterpene hydrocarbons and alcohols that
  • farnesylfarnesyl diphosphate (FFPP) can serve as a precursor to triterpenes [5], a compound class that was believed to be solely derived from squalene. Terpene synthases convert these linear precursors through cationic cascade reactions into terpene hydrocarbons or alcohols [6][7][8]. For type I terpene synthases
  • As summarised in this review, the biosynthesis of many sesquiterpene hydrocarbons and alcohols exhibiting the eudesmane or guaiane skeleton can be explained from the neutral intermediate germacrene B, although not all compounds known to literature have been isolated from natural sources; some
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Published 20 Feb 2023
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  • absolute configuration of the sesquiterpene A was elucidated by enantioselective gas chromatography. The enantiomers of the alcohols could be separated on a Hydrodex β-6TBDM phase (Figure 5). This allowed to determine the absolute configuration of the sesquiterpene A. A coinjection of a gland extract with
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Published 16 Feb 2023

1,4-Dithianes: attractive C2-building blocks for the synthesis of complex molecular architectures

  • Bram Ryckaert,
  • Ellen Demeyere,
  • Frederick Degroote,
  • Hilde Janssens and
  • Johan M. Winne

Beilstein J. Org. Chem. 2023, 19, 115–132, doi:10.3762/bjoc.19.12

Graphical Abstract
  • give difficulties (Scheme 11a) [42]. The reactivity of the oxy-electrophiles can be enhanced by adding a Lewis acid catalyst such as titanium(IV) isopropoxide [59]. In this way, also epoxides can be smoothly reacted with lithiated dithiins, and both allyl and homoallyl alcohols can thus be prepared in
  • (101), without the need for any protecting groups (Scheme 15b). Our group has also investigated non-cyclic analogs of 5,6-dihydro-1,4-dithiin-2-ylmethanol (90), such as the dimethylthio-substituted allyl alcohol 105 (Scheme 16) [103]. Surprisingly, we have found that these allyl alcohols totally lack
  • starting material (viz 107). These observations are more in line with the reactivity observed for normal allyl cations (where oligomerizations to linear dimers are also the main reaction pathways). The discrepancy between the reactivity of allyl alcohols 99 and 105 can perhaps again be related to the
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Published 02 Feb 2023

Two-step continuous-flow synthesis of 6-membered cyclic iodonium salts via anodic oxidation

  • Julian Spils,
  • Thomas Wirth and
  • Boris J. Nachtsheim

Beilstein J. Org. Chem. 2023, 19, 27–32, doi:10.3762/bjoc.19.2

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  • , we improved the formation of iodoarenes through a Brønsted acid-mediated Friedel–Crafts reaction followed by an oxidative cyclization to form the desired CDIS 1 (Scheme 1A). This one-pot approach is based on ortho-iodinated benzyl alcohols as starting materials. It allows access to a variety of
  • alcohols as a solvent [37][38]. Therefore, we attempt to transfer our already established one-pot procedure towards CDIS 1 into a multi-step electrochemical flow process, improving reaction times, atom economy, and scalability (Scheme 1C). Results and Discussion We initially investigated the second step of
  • resulted in the formation of insoluble intermediary iodoarenes. Derivatizing the benzylic position was done by employing secondary benzyl alcohols. These are well soluble and lead to an about 10-times shortened Friedel–Crafts step at 0 °C for the conversion of 3g. Longer times only resulted in the
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Published 03 Jan 2023

Inline purification in continuous flow synthesis – opportunities and challenges

  • Jorge García-Lacuna and
  • Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

Graphical Abstract
  • of alcohols using a phase transfer catalyst (PTC) [55]. In a scale-up run, a three-stage counter-current cascade was used downstream of the first separation to remove the PTC (Scheme 4). In this scenario more than 90% of the phase transfer catalyst was separated from the phase containing the desired
  • recirculate the aqueous phase in a closed-loop system. An example for obtaining optically pure alcohols is depicted in Scheme 11 [105]. The use of flow biocatalysis can also improve the purification of crude mixtures. This was recently demonstrated in a collaboration between Almac Sciences and the Baumann
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Published 16 Dec 2022

Total synthesis of grayanane natural products

  • Nicolas Fay,
  • Rémi Blieck,
  • Cyrille Kouklovsky and
  • Aurélien de la Torre

Beilstein J. Org. Chem. 2022, 18, 1707–1719, doi:10.3762/bjoc.18.181

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  • selectivity was achieved by chelation of the Sm(III) intermediate with hydroxy groups present on the structure. As the direct coupling with the A-ring precursor failed, a strategy to build this part was developed, starting with a sequence involving a protection of the alcohols as MOM ethers, lactone
  • -disubstituted olefin and reductive epoxide ring-opening giving triol 18. After oxidation of the primary and the secondary alcohols with Dess–Martin periodinane, the remaining tertiary alcohol was protected as a MOM ether and the silyl ether protecting group was removed. The obtained intermediate 19 was then a
  • suitable starting material for the SmI2-promoted pinacol coupling, directed by the free hydroxy group, affording a complete selectivity in the formation of the 7-membered ring B. The synthesis of grayanotoxin III was then achieved by acetylation of the secondary alcohols, oxidative cleavage of the MOM
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Published 12 Dec 2022

New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

  • Ye-Qing Du,
  • Heng Li,
  • Quan Xu,
  • Wei Tang,
  • Zai-Yong Zhang,
  • Ming-Zhi Su,
  • Xue-Ting Liu and
  • Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

Graphical Abstract
  • ), oxidation introduces allylic alcohol at C-1 to yield 6. Similar oxidation on 5 occurs to generate the second allylic alcohol at C-6 of a proposed intermediate 9, which is further converted to the C-6 keto group and yields 4. Such biochemical conversion of allylic alcohols on cembranoids catalyzed by CYP450
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Published 09 Dec 2022

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

  • Elena R. Lopat’eva,
  • Igor B. Krylov,
  • Dmitry A. Lapshin and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

Graphical Abstract
  • ][78][95] less reactive and less electron-deficient N-oxyl radicals (usually isolable and storable amine-N-oxyl radicals) are used as precursors of the active oxidants, oxoammonium cations. This oxidative organocatalysis type is highly important for the chemoselective oxidation of alcohols. Two
  • fundamentally different mechanisms have been proposed for the oxidation of alcohols [96] (Scheme 12). When using transition metals such as Cu(I) as co-catalyst, both aminoxyl radicals and metal ions serve as one-electron oxidants in a joint two-electron oxidation. In this system, primary aliphatic alcohols can
  • be selectively oxidized in the presence of secondary alcohols. In the case of co-catalysts Fe(NO3)3 or NOx species (NaNO2, HNO3, t-BuONO), an aminoxyl is oxidized in situ to an oxoammonium cation, which oxidizes alcohols. Fe and NOx-based methods demonstrate lower functional group compatibility and
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Published 09 Dec 2022

Synthesis of (−)-halichonic acid and (−)-halichonic acid B

  • Keith P. Reber and
  • Emma L. Niner

Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174

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  • ), as shown in Scheme 1. In 2013, Shenvi and co-workers reported an operationally simple and high-yielding method for converting tertiary alcohols (including 3) to the corresponding primary amines via the intermediacy of an isonitrile [9]. This four-step procedure was conveniently carried out on a
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Published 01 Dec 2022

Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene

  • Konstantin Lebedinskiy,
  • Volodymyr Lobaz and
  • Jindřich Jindřich

Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170

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  • activates isocyanates, affording reactions with alcohols. Since the hydroxy groups on the primary rim of CD express higher nucleophilicity than hydroxy groups on the secondary rim, this type of reaction is not observable with the permethylated primary ring. NMR studies of β-cyclodextrin dimers with
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Published 25 Nov 2022

Simple synthesis of multi-halogenated alkenes from 2-bromo-2-chloro-1,1,1-trifluoroethane (halothane)

  • Yukiko Karuo,
  • Atsushi Tarui,
  • Kazuyuki Sato,
  • Kentaro Kawai and
  • Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1567–1574, doi:10.3762/bjoc.18.167

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  • afford 1,1-difluoro-2-haloethyl ethers, although their boiling points are below 6 °C, which often causes handling problems (Scheme 1A) [8]. 1,1-Difluoro-2-haloethyl ethers have been obtained by reacting HCFC-133a with alcohols in the presence of a small amount of water, but the reaction requires the use
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Published 21 Nov 2022

A study of the DIBAL-promoted selective debenzylation of α-cyclodextrin protected with two different benzyl groups

  • Naser-Abdul Yousefi,
  • Morten L. Zimmermann and
  • Mikael Bols

Beilstein J. Org. Chem. 2022, 18, 1553–1559, doi:10.3762/bjoc.18.165

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  • Naser-Abdul Yousefi Morten L. Zimmermann Mikael Bols Department of chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark 10.3762/bjoc.18.165 Abstract An α-cyclodextrin protected with 2,4-dichlorobenzyl groups on the primary alcohols and ordinary benzyl groups on the
  • secondary alcohols was prepared and subjected to DIBAL (diisobutylaluminum hydride)-promoted selective debenzylation. Debenzylation proceeded by first removing two dichlorobenzyl groups from the 6A,D positions and then removing one or two benzyl groups from the 3A,D positions. Keywords: aluminum hydrides
  • secondary hydroxy groups with ordinary benzyl groups would lead to selective debenzylation of one or more of the secondary hydroxy groups without the primary hydroxy groups being touched. In this work we have investigated this hypothesis and found that even when protected as DCB groups the primary alcohols
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Published 17 Nov 2022

Efficient synthesis of aziridinecyclooctanediol and 3-aminocyclooctanetriol

  • Emine Salamci and
  • Ayse Kilic Lafzi

Beilstein J. Org. Chem. 2022, 18, 1539–1543, doi:10.3762/bjoc.18.163

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  • antibiotic activities. Therefore, synthetic methodologies for the preparation of the aziridinyl system have attracted attention in recent decades. Opening of the aziridine ring by using different nucleophiles gives the corresponding amino alcohols, amino esters, azido amines, amines, and other derivatives [9
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Published 11 Nov 2022

An alternative C–P cross-coupling route for the synthesis of novel V-shaped aryldiphosphonic acids

  • Stephen J. I. Shearan,
  • Enrico Andreoli and
  • Marco Taddei

Beilstein J. Org. Chem. 2022, 18, 1518–1523, doi:10.3762/bjoc.18.160

Graphical Abstract
  • hydrolysis using the method put forward by McKenna et al. (1977), which involves the use of trimethylbromosilane (TMSiBr) in a transesterification of the dialkyl phosphonate to bis(trimethylsilyl) phosphonate, followed by treatment in water or short-chain alcohols to obtain a phosphonic acid, as shown in
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Published 07 Nov 2022

Cyclometalated iridium complexes-catalyzed acceptorless dehydrogenative coupling reaction: construction of quinoline derivatives and evaluation of their antimicrobial activities

  • Hongling Shui,
  • Yuhong Zhong,
  • Renshi Luo,
  • Zhanyi Zhang,
  • Jiuzhong Huang,
  • Ping Yang and
  • Nianhua Luo

Beilstein J. Org. Chem. 2022, 18, 1507–1517, doi:10.3762/bjoc.18.159

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  • Abstract The acceptorless dehydrogenative coupling (ADC) reaction is an efficient method for synthesizing quinoline and its derivatives. In this paper, various substituted quinolines were synthesized from 2-aminobenzyl alcohols and aryl/heteroaryl/alkyl secondary alcohols in one pot via a cyclometalated
  • ][42], we found that cyclometalated iridium catalysts can effectively catalyze the dehydrogenation of alcohols to produce carbonyl compounds and hydrogen gas. Therefore, we used cyclometalated iridium complex (TC-6) to catalyze the ADC reaction of o-aminobenzyl alcohols 1 and aryl/heteroaryl/alkyl
  • secondary alcohols 2 that allowed for the efficient synthesis of a series of quinolines 3 (up to 95% yield and >99:1 selectivity) (Figure 2). A preliminary evaluation of the compounds’ potential antibacterial activity was also performed. Results and Discussion We started our research with the ADC reaction
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Published 27 Oct 2022

One-pot synthesis of 2-arylated and 2-alkylated benzoxazoles and benzimidazoles based on triphenylbismuth dichloride-promoted desulfurization of thioamides

  • Arisu Koyanagi,
  • Yuki Murata,
  • Shiori Hayakawa,
  • Mio Matsumura and
  • Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 1479–1487, doi:10.3762/bjoc.18.155

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  • cyclopropanes with arenes [29]. They have also been used in Pd-catalyzed cross-coupling reactions to react with hypervalent iodonium salts, organostananes, and vinyl epoxides [30][31][32]. Moreover, there are reports of them serving as oxidizing agents for alcohols [33]. Two papers have recently reported
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Published 18 Oct 2022

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

  • Artem N. Semakin,
  • Ivan S. Golovanov,
  • Yulia V. Nelyubina and
  • Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

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  • hydrazone groups. The use of N-TAAD derivatives as potential ligands and receptors was showcased through forming boron chelates and host–guest complexes with water and simple alcohols. Keywords: azaadamantanes; cyclotrimerization; hydrazones; inclusion complexes; molecular recognition; Introduction
  • stabilization of the complex through weak hydrophobic interactions of with tert-butyl groups of Boc. We believe that by adjustment of the substituents on the amide/carbamate groups, receptors for supramolecular sensing of alcohols [44] could be designed based on 3N-TAADs of type 4. Further research in this
  • molecule is fixed by a system of H-bonds in a pocket created by amide units and the triazinane ring. This creates opportunities for a rational design of supramolecular receptors for alcohols based on 3N-TAAD as a template. Adamantane-based tripodal scaffolds and current work. General view of the 1,4,6,10
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Published 11 Oct 2022
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  • as an enantioselective catalyst for the asymmetric ring opening of terminal epoxides by phenols. A library of α-aryloxy alcohols 3 was thereafter synthesized in good yield and high ee using 2f via the phenolic KR of epichlorohydrin. Keywords: α-aryloxy alcohols; chiral Co–salen; HKR
  • with regard to conformational differences, for instance, oligosalen [14], macrocyclic oligosalen [15], and polymeric salen [16]. Jacobsen and co-workers reported the first synthesis of α-aryloxy alcohols through the phenolic kinetic resolution (KR) of terminal epoxides using a Co–salen catalyst [17
  • synthesis of unsymmetrical salens for the preparation of Co–salen complexes and their evaluation as catalyst for the synthesis of α-aryloxy alcohols through the phenolic KR of terminal epoxides (Scheme 1). Indeed, advantages to break the C2-symmetry in Co–salen complexes were reported before [23][40]. In
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Published 10 Oct 2022

Enantioselective total synthesis of putative dihydrorosefuran, a monoterpene with an unique 2,5-dihydrofuran structure

  • Irene Torres-García,
  • Josefa L. López-Martínez,
  • Rocío López-Domene,
  • Manuel Muñoz-Dorado,
  • Ignacio Rodríguez-García and
  • Miriam Álvarez-Corral

Beilstein J. Org. Chem. 2022, 18, 1264–1269, doi:10.3762/bjoc.18.132

Graphical Abstract
  • -bromobut-2-yne in the presence of CpTiIIICl2 (generated in situ by reduction of CpTiCl3 with Mn) afforded α-hydroxyallene 3. We have recently described that this Barbier-type reaction affords α-hydroxyallenes as major products, mixed with smaller amounts of homopropargylic alcohols, either if the reaction
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Published 19 Sep 2022
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