A selective removal of the secondary hydroxy group from ortho-dithioacetal-substituted diarylmethanols

• Anna Czarnecka,
• Emilia Kowalska,
• Agnieszka Bodzioch,
• Joanna Skalik,
• Marek Koprowski,
• Krzysztof Owsianik and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2018, 14, 1229–1237, doi:10.3762/bjoc.14.105

• was observed instead [23]. Diarylmethanes were also obtained in the Friedel–Crafts reactions of arenes with primary benzyl alcohols, aryl acetals, and benzyl esters [1]. Benzyl fluorides (in 1,1,1,3,3,3-hexafluoroisopropanol in the presence of a catalytic amount of trifluoroacetic acid [24]) as well

Mannich base-connected syntheses mediated by ortho-quinone methides

• Petra Barta,
• Ferenc Fülöp and
• István Szatmári

Beilstein J. Org. Chem. 2018, 14, 560–575, doi:10.3762/bjoc.14.43

• on its benzylic carbon atom. Rueping et al. recently performed reactions between aza-o-QMs in situ generated from α-substituted ortho-amino benzyl alcohols 48 and substituted indoles catalysed by N-triflylphosphoramides (NTPAs) [85]. (Scheme 6) The process provided new C-2 and C-3-functionalized

Stereochemical outcomes of C–F activation reactions of benzyl fluoride

• Neil S. Keddie,
• Pier Alexandre Champagne,
• Justine Desroches,
• Jean-François Paquin and
• David O'Hagan

Beilstein J. Org. Chem. 2018, 14, 106–113, doi:10.3762/bjoc.14.6

• ) previously as the liquid-crystalline matrix for the determination of ee of samples of deuterated benzyl alcohols, benzyl fluorides, and esters of fluoroacetic acid [11] by 2H NMR and found it to be effective for the resolution of enantiomers. In this study, we explore various nucleophilic substitutions and a

One-pot syntheses of blue-luminescent 4-aryl-1H-benzo[f]isoindole-1,3(2H)-diones by T3P^® activation of 3-arylpropiolic acids

• Melanie Denißen,
• Alexander Kraus,
• Guido J. Reiss and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 2340–2351, doi:10.3762/bjoc.13.231

• activation of benzyl alcohols in the synthesis of N-benzylphenothiazine derivatives [48], we reasoned that T3P® might be equally well suited for furnishing 4-phenylnaphtho[2,3-c]furan-1,3-diones, and thereby opening a straightforward entry to 4-aryl-1H-benzo[f]isoindole-1,3(2H)-diones in a diversity-oriented

Mechanically induced oxidation of alcohols to aldehydes and ketones in ambient air: Revisiting TEMPO-assisted oxidations

• Andrea Porcheddu,
• Evelina Colacino,
• Giancarlo Cravotto,
• Francesco Delogu and
• Lidia De Luca

Beilstein J. Org. Chem. 2017, 13, 2049–2055, doi:10.3762/bjoc.13.202

• cycles, gave 2b in 96% overall yield even on the gram scale. On the gram scale, the mechanical activation no longer required an additional solvent to recover the final aldehyde during purification. With the optimized reaction conditions in hand, a series of common benzyl alcohols 1b–n with different

• functional groups was then tested in order to examine the scope of the reaction (Scheme 3). To our satisfaction, very high yields (>90%) were obtained with all tested compounds, except 2n (39%). Benzyl alcohols containing alkyl or aryl groups on the aromatic ring were all transformed into the desired

• 1o–v. Excellent yields of the ketones 2o–v were obtained (Scheme 4). Notably, the product yield was not significantly affected by the position or electronic nature of the substituents on the aromatic ring of the alcohols. Encouraged by the facile oxidation of benzyl alcohols, the scope of the

New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions

• Daily Rodríguez-Padrón,
• Alina M. Balu,
• Antonio A. Romero and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1982–1993, doi:10.3762/bjoc.13.194

• substituted benzyl alcohols. Although benzyl alcohol is industrially produced by reduction of benzaldehyde, this aldehyde is considered as the second most important flavoring molecule after vanillin, due to its variety of applications in cosmetics, perfumes, food, dyes, agrochemicals and pharmaceuticals [41

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• ][133] in which the component aldehyde and catalytic amount of acid were generated in situ for the final step of dihydropyrimidinone synthesis. Benzyl alcohols were oxidized by a reagent combination of oxone (0.6 equiv), KBr (10 mol %) and 2,2,6,6-tetramethylpiperidin-1-yloxy radical (TEMPO, 1 mol %) to

First DMAP-mediated direct conversion of Morita–Baylis–Hillman alcohols into γ-ketoallylphosphonates: Synthesis of γ-aminoallylphosphonates

• Marwa Ayadi,
• Haitham Elleuch,
• Emmanuel Vrancken and
• Farhat Rezgui

Beilstein J. Org. Chem. 2016, 12, 2906–2915, doi:10.3762/bjoc.12.290

• , followed by thermal Arbuzov rearrangement of the intermediate allyl phosphites (Scheme 1, reaction 1). Recently, an efficient protocol for the conversion of common allyl and benzyl alcohols into the corresponding phosphonates through their treatment with triethyl phosphite and ZnI2, was described [16

New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

• Pavel Nagorny and
• Zhankui Sun

Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283

• which a halogen-containing acceptor is formed in transient quantities. Thus, in 2015, Takemoto and co-workers described a halogen bond donor-catalyzed dehydroxylative coupling reaction of benzyl alcohols and allyltrimethylsilane (Scheme 21) [92]. This transformation requires catalytic quantities of the

Selective synthesis of thioethers in the presence of a transition-metal-free solid Lewis acid

• Federica Santoro,
• Matteo Mariani,
• Federica Zaccheria,
• Rinaldo Psaro and
• Nicoletta Ravasio

Beilstein J. Org. Chem. 2016, 12, 2627–2635, doi:10.3762/bjoc.12.259

• ] dispersed on silica is active in promoting the substitution of adamantanol, cinnamyl and benzyl alcohols with thiols whereupon significative amounts of Zr salt are required; whereas Wu and Han have shown that Ga(OTf)3 is an effective catalyst for the substitution of a wide range of benzylic and allylic

Solvent-free, visible-light photocatalytic alcohol oxidations applying an organic photocatalyst

• Martin Obst and
• Burkhard König

Beilstein J. Org. Chem. 2016, 12, 2358–2363, doi:10.3762/bjoc.12.229

• ][10][11][12]. Some derivatives were also immobilized on silica gel and applied in the oxidation of benzyl alcohols [13]. Furthermore, it was shown that the oxidation power of RFTA can be increased by coordination to scandium triflate [14]. Recently, the E/Z-isomerization of olefins with riboflavin as

• a novel rod mill apparatus. The applicability of the rod mill was shown for the oxidation of benzylic alcohols with riboflavin tetraacetate as photocatalyst under blue light irradiation; the products were isolated in moderate to good yields. In case of the solid benzyl alcohols, the reactions were

Unconventional application of the Mitsunobu reaction: Selective flavonolignan dehydration yielding hydnocarpins

• Guozheng Huang,
• Simon Schramm,
• Jörg Heilmann,
• David Biedermann,
• Vladimír Křen and
• Michael Decker

Beilstein J. Org. Chem. 2016, 12, 662–669, doi:10.3762/bjoc.12.66

• alcohols and bulky acids: Cherney and Wang observed an elimination of a serine derivative during esterification experiments [23]. During conversion of substituted benzyl alcohols to amines under Mitsunobu conditions, elimination also occurred [24]. Dehydration under Mitsunobu conditions has been applied in

Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis

• David W. Manley and
• John C. Walton

Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173

• substituents, 65, returned the corresponding benzyl alcohols 66 in moderate to good yields. Naphthaldehyde and heteroaromatic aldehydes 67 also hydrogenated very smoothly under these conditions (Scheme 13). The HO groups attached to the TiO2 surface probably again play key roles in TiO2 SCPC hydrogenations

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

• equivalent amount of alcohol. 2.2 Oxidative systems based on noble metals and oxygen The oxidative coupling of benzyl alcohols with aliphatic alcohols in the presence of Pd(II) salt/Ag(I) salt/base/oxygen system was proposed [96][97]. In the study [97], phosphine ligands were additionally employed. It is

• ], Py·HBr3 [136], N-bromosuccinimide/pyridine [137], N-iodosuccinimide/K2CO3 [138], and N,N'-diiodo-N,N'-1,2-ethanediylbis(p-toluenesulfonamide) [139]. The oxidative C–O coupling of benzyl alcohols 135 with alkylarenes 136 took place under the action of the Bu4NI/t-BuOOH system in the presence of NaH2PO4

• , xylenes, 1,3,5-trimethylbenzene, 2,4-dichlorotoluene, and ethylbenzene. α-Acyloxy ethers 180 were synthesized by the oxidative coupling of benzyl alcohols 178 with ethers 179 (dioxane, tetrahydropyran, tetrahydrofuran, 1,2-dimethoxyethane) using Cu(OAc)2/t-BuOOH system [152] (Scheme 37). In a series of

Diversity-oriented synthesis of dihydrobenzoxazepinones by coupling the Ugi multicomponent reaction with a Mitsunobu cyclization

• Lisa Moni,
• Luca Banfi,
• Andrea Basso,
• Alice Brambilla and
• Renata Riva

Beilstein J. Org. Chem. 2014, 10, 209–212, doi:10.3762/bjoc.10.16

• ]. On the other hand, various ortho-hydroxybenzyl alcohols are on the market or can be easily prepared from the corresponding salicylaldehydes or salicylic acids. Thus we decided to set up a general and efficient strategy to access the desired amines, through conversion of the benzyl alcohols into

• –d were straightforwardly prepared in excellent yields from low cost starting materials 1, 3, 4, and 7, in all cases passing through the benzyl alcohols (Scheme 1). Apart from 2a [11], they are all new compounds. Initially we reduced azide 2a with PPh3 and separated the amine from triphenylphosphine

A Lewis acid-promoted Pinner reaction

• Dominik Pfaff,
• Gregor Nemecek and
• Joachim Podlech

Beilstein J. Org. Chem. 2013, 9, 1572–1577, doi:10.3762/bjoc.9.179

• possible. Phenols are not acylated under these reaction conditions. The method has been used for the first total synthesis of the natural product monaspilosin. In the reaction of benzyl alcohols variable amounts of amides are formed in a Ritter-type side reaction. Keywords: carbonitriles; carboxylic

• by Cheng et al. [18]. This compound was reported to have radical scavenger properties. The first total synthesis of this natural product was herewith achieved with 73% yield in only one step. Good yields were observed, when benzyl alcohols with electron withdrawing (−M) substituents such as 4

• significant amounts of carboxamides. These amides result from a Ritter-type reaction [19][20][21], where a carbenium ion (or a substrate with significant positive partial charge) reacts at the nitrogen atom of a nitrile. This transformation is a competition to the Pinner reaction, when benzyl alcohols are

ML212: A small-molecule probe for investigating fluconazole resistance mechanisms in Candida albicans

• Willmen Youngsaye,
• Cathy L. Hartland,
• Barbara J. Morgan,
• Amal Ting,
• Partha P. Nag,
• Benjamin Vincent,
• Carrie A. Mosher,
• Joshua A. Bittker,
• Sivaraman Dandapani,
• Michelle Palmer,
• Luke Whitesell,
• Susan Lindquist,
• Stuart L. Schreiber and
• Benito Munoz

Beilstein J. Org. Chem. 2013, 9, 1501–1507, doi:10.3762/bjoc.9.171

• bromoacetate and potassium carbonate in hot acetone completed the synthesis of compounds 7. In order to prepare 3-alkylindazoles, 2-fluorobenzaldehyde was first treated with alkylmagnesium bromides, and the resulting benzyl alcohols were immediately oxidized with Dess–Martin reagent. Alkyl phenyl ketones 9 and

Metal-free aerobic oxidations mediated by N-hydroxyphthalimide. A concise review

• Lucio Melone and
• Carlo Punta

Beilstein J. Org. Chem. 2013, 9, 1296–1310, doi:10.3762/bjoc.9.146

• system could promote the nitric aerobic oxidation of alkylbenzenes under NHPI-catalysis, leading to the selective formation of benzyl alcohols through the corresponding acetates, if operating in acetic acid solution (Scheme 10) [26]. According to the proposed mechanism, being that the concentrations of

• ) with 2,2’-azinobis(3-ethylbenzthiazoline-6-sulfonate) (ABTS), which was the first to be used among mediators of laccase [29]. Laccase-NHDs mediator systems were successfully employed for the aerobic oxidation of nonphenolic substrates such as benzyl alcohols [27][28][30][31] and ethers [32]. Whereas

• versus the substrate. In fact, the laccase-TEMPO system, which operates through an ionic route by formation of oxammonium ion as NHDs-Medox, resulted in particularly efficient promotion of the oxidation of benzyl alcohols, while it gave poor performances when applied in the presence of ethers. In

A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis

• Magnus Rueping and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2010, 6, No. 6, doi:10.3762/bjoc.6.6

• environmentally benign substrates which can be applied today as an approach towards greener processes. Additionally, the first diastereoselective and enantioselective Friedel–Crafts-type alkylations will be highlighted. Keywords: allyl alcohols; arene; asymmetric Friedel–Crafts reaction; benzyl alcohols; Friedel

• . Review The FC alkylation with benzyl alcohols – An efficient approach to 1,1-diarylalkanes 1,1-Diarylalkanes are important building blocks for the synthesis of many pharmaceuticals, agro- and fine chemicals (Figure 2). Traditionally, 1,1-diarylalkanes have been prepared from benzyl halides under Friedel

• reagents are highly desirable. To this end substantial progress has been made and different benzyl halide substitutes, including free and protected alcohols as well as tosylamides have been introduced (Scheme 2). In particular benzyl alcohols have become a valuable alternative. Due to their availability

1-(4-Alkyloxybenzyl)-3-methyl-1H-imidazol-3-ium organic backbone: A versatile smectogenic moiety

• William Dobbs,
• Laurent Douce and
• Benoît Heinrich

Beilstein J. Org. Chem. 2009, 5, No. 62, doi:10.3762/bjoc.5.62

• benzyl alcohols An. The different resulting alcohols were converted quantitatively into the intermediate 4-(alkoxy)benzyl bromides with thionyl bromide. The final compounds 1n were then obtained by quaternization of 1-methylimidazole with the bromides in refluxing THF under inert atmosphere (Scheme 1

Synthesis of methylenebisamides using CC- or DCMT- activated DMSO

• Qiang Wang,
• Lili Sun,
• Yu Jiang and
• Chunbao Li

Beilstein J. Org. Chem. 2008, 4, No. 51, doi:10.3762/bjoc.4.51

• on the chlorination [10] and etherification [11] of benzyl alcohols and from other references [12][13][14], we believe the reaction between 2,4,6-trichloro[1,3,5]triazine (cyanogen chloride, or CC) and DMSO produces a reactive sulfonium salt intermediate. Therefore, it was of interest to study the