The crystal structure of the Dess–Martin periodinane

• Albert Schröckeneder,
• Desiree Stichnoth,
• Peter Mayer and
• Dirk Trauner

Beilstein J. Org. Chem. 2012, 8, 1523–1527, doi:10.3762/bjoc.8.172

• periodinane; halogen bonds; hypervalent iodine; oxidant; Introduction The so-called Dess–Martin periodinane (DMP, 1,1,1-triacetoxy-1,1-dihydro-1,2-benziodoxol-3(1H)-one, 1) has emerged as one of the most useful reagents for the oxidation of primary and secondary alcohols to the corresponding aldehydes and

Reduction of benzylic alcohols and α-hydroxycarbonyl compounds by hydriodic acid in a biphasic reaction medium

• Michael Dobmeier,
• Josef M. Herrmann,
• Dieter Lenoir and
• Burkhard König

Beilstein J. Org. Chem. 2012, 8, 330–336, doi:10.3762/bjoc.8.36

• , secondary alcohols give best results, while others may react less efficiently. We have reinvestigated the long-known reduction of benzylic alcohols and α-hydroxycarbonyl compounds by hydriodic acid [22][23][24][25][26][27][28][29][30][31][32]. The method has been reported for a variety of alcohols, but

Efficient and selective chemical transformations under flow conditions: The combination of supported catalysts and supercritical fluids

• M. Isabel Burguete,
• Eduardo García-Verdugo and
• Santiago V. Luis

Beilstein J. Org. Chem. 2011, 7, 1347–1359, doi:10.3762/bjoc.7.159

• . Different examples can be found, in this regard, in the literature. The most common transformations are the kinetic resolution (KR) of secondary alcohols. For example, Matsuda has reported the use of the commercially available supported lipase Novozym 435 for the kinetic resolution of aromatic and

Cyclization of 5-hexynoic acid to 3-alkoxy-2-cyclohexenones

• Anne T. Hylden,
• Eric J. Uzelac,
• Zeljko Ostojic,
• Ting-Ting Wu,
• Keely L. Sacry,
• Krista L. Sacry,
• Lin Xi and
• T. Nicholas Jones

Beilstein J. Org. Chem. 2011, 7, 1323–1326, doi:10.3762/bjoc.7.155

• formed from esterification of unreacted oxalyl chloride with excess alcohol nucleophiles, and thus a basic hydrolysis step was added to our work-up procedure. Secondary alcohols required heating to 90 °C following addition of the alcohol nucleophile to promote product formation. IR and NMR spectral data

A straightforward approach towards combined α-amino and α-hydroxy acids based on Passerini reactions

• Ameer F. Zahoor,
• Sarah Thies and
• Uli Kazmaier

Beilstein J. Org. Chem. 2011, 7, 1299–1303, doi:10.3762/bjoc.7.151

• epoxides, followed by oxidation of the hydroxy amino acid formed. While aryl-substituted epoxides react preferentially at the benzylic position giving rise to the terminal primary alcohols [25], the corresponding alkyl-substituted epoxides provide secondary alcohols 1 by nucleophilic attack of the enolate

Functionalization of heterocyclic compounds using polyfunctional magnesium and zinc reagents

• Paul Knochel,
• Matthias A. Schade,
• Sebastian Bernhardt,
• Georg Manolikakes,
• Albrecht Metzger,
• Fabian M. Piller,
• Christoph J. Rohbogner and
• Marc Mosrin

Beilstein J. Org. Chem. 2011, 7, 1261–1277, doi:10.3762/bjoc.7.147

• chloride 165 react at room temperature with the aromatic aldehydes to provide the secondary alcohols 164 and 166 in 87–91% yield. The alkyl zinc reagent 167 adds to α,α,α-trifluoromethylacetophenone in 2 h and the corresponding alcohol 168 was isolated in 76% yield. Furthermore, the method was applied to

Amine-linked diglycosides: Synthesis facilitated by the enhanced reactivity of allylic electrophiles, and glycosidase inhibition assays

• Ian Cumpstey,
• Jens Frigell,
• Elias Pershagen,
• Tashfeen Akhtar,
• Elena Moreno-Clavijo,
• Inmaculada Robina,
• Dominic S. Alonzi and
• Terry D. Butters

Beilstein J. Org. Chem. 2011, 7, 1115–1123, doi:10.3762/bjoc.7.128

• ]. Reports of Mitsunobu reactions of secondary alcohols in fully functionalized carbohydrates are much scarcer. Rather, reports exist of failed attempts at Mitsunobu reactions of secondary carbohydrate alcohols [23] or the selective functionalisation of primary carbohydrate alcohols in the presence of

• secondary alcohols [24]. Some examples of successful reactions do exist, though, for oxygen, nitrogen and sulfur nucleophiles [25][26][27][28]. Unsaturated carbohydrates, similar to those described here, have also been reported to undergo Mitsunobu reaction with simple, non-carbohydrate nucleophiles [29][30

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

• alcohols has been developed by utilizing NaAuCl4. The benzylic and secondary alcohols (55 and 58) worked well under mild conditions with low catalyst loading (Scheme 11). The chiral benzyl alcohol 60 gave racemic ether 61, which suggested the intermediacy of a carbocation. Ye et al. reported an expedient

Asymmetric synthesis of tertiary thiols and thioethers

• Jonathan Clayden and
• Paul MacLellan

Beilstein J. Org. Chem. 2011, 7, 582–595, doi:10.3762/bjoc.7.68

• reaction is successful with a wide range of primary and secondary alcohols, but Mitsunobu-type reactions are very sensitive to steric bulk at the electrophilic carbon atom. For example, reaction of alcohol 25 with a phenol under standard Mitsunobu conditions at 50 °C for 16 hours provides only a trace

Synthesis of glycoconjugate fragments of mycobacterial phosphatidylinositol mannosides and lipomannan

• Benjamin Cao,
• Jonathan M. White and
• Spencer J. Williams

Beilstein J. Org. Chem. 2011, 7, 369–377, doi:10.3762/bjoc.7.47

• the glycosidic linkage. For α-mannosylation of primary and secondary alcohols, the mannosyl donors 16 [38] and 17 were used. Treatment of glycosyl bromide 11 with NaBH4/KI in MeCN [39] afforded the crystalline 1,2-O-benzylidene acetal 18 as a single diastereoisomer in quantitative yield (Scheme 3

Achiral bis-imine in combination with CoCl₂: A remarkable effect on enantioselectivity of lipase-mediated acetylation of racemic secondary alcohol

• K. Arunkumar,
• M. Appi Reddy,
• T. Sravan Kumar,
• B. Vijaya Kumar,
• K. B. Chandrasekhar,
• P. Rajender Kumar and
• Manojit Pal

Beilstein J. Org. Chem. 2010, 6, 1174–1179, doi:10.3762/bjoc.6.134

• -imines in combination with CoCl2 [16] in the lipase-mediated acetylation of a benzylic secondary alcohols. Accordingly, a number of achiral bis-imines were prepared and used to generate the desired complex. While a number of methods have been reported to prepare Schiff bases by reacting an amine with a

Concise methods for the synthesis of chiral polyoxazolines and their application in asymmetric hydrosilylation

• Wei Jie Li,
• Zun Le Xu and
• Sheng Xiang Qiu

Beilstein J. Org. Chem. 2010, 6, No. 29, doi:10.3762/bjoc.6.29

• ][30][31][32][33], while enantioselective hydrogenation of prochiral ketones to optically active secondary alcohols is among the most fundamental subjects in modern synthetic chemistry. In this article, with the new polyoxazoline ligands in hand, the Rh-catalyzed hydrosilylation of aromatic ketones was

• . Under the optimized conditions described above, the hydrosilylation of various aryl-substituted ketones catalyzed by [Rh(COD)Cl]2 in the presence of ligand 2 gave the corresponding secondary alcohols with good enantioselectivities. The results of all the reactions are shown in Table 3 in terms of the

The development and evaluation of a continuous flow process for the lipase- mediated oxidation of alkenes

• Charlotte Wiles,
• Marcus J. Hammond and
• Paul Watts

Beilstein J. Org. Chem. 2009, 5, No. 27, doi:10.3762/bjoc.5.27

• increasing productivity, biocatalyst lifetimes and exploring the potential of employing immobilised enzymes in industrial processes. Recent examples include the continuous flow enantioselective acetylation of a series of racemic secondary alcohols [27] and the continuous flow synthesis of alkyl esters [28

Green oxidations: Titanium dioxide induced tandem oxidation coupling reactions

• Vineet Jeena and
• Ross S. Robinson

Beilstein J. Org. Chem. 2009, 5, No. 24, doi:10.3762/bjoc.5.24

• 3b in a satisfactory isolated yield of 60%. The coupling of secondary alcohols 1c and 1d both proceeded smoothly, even though the hindered alcohol 1c required a longer reaction time. Finally, the diamine component was varied (entries v-vii) with satisfactory yields obtained for both primary and

• secondary alcohols. Concerning the mechanism, when titanium dioxide is irradiated with an appropriate energy source, electrons are promoted from the valence band to the conduction band leaving behind positive holes in the valence band [20]. The positive holes and electrons migrate to the surface where the

A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed- bed microreactor

• Andrew Bogdan and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2009, 5, No. 17, doi:10.3762/bjoc.5.17

• characterization of a simplified packed-bed microreactor using an immobilized TEMPO catalyst shown to oxidize primary and secondary alcohols via the biphasic Anelli-Montanari protocol. Oxidations occurred in high yields with great stability over time. We observed that plugs of aqueous oxidant and organic alcohol

• functionalized with a range of catalysts and works well as packing material for flow chemistry [39]. In this report, we demonstrate the immobilization of TEMPO and its use in a flow system using the Anelli-Montanari protocol for the oxidation of primary and secondary alcohols [30][40]. Our simplified reactor is

• flow conditions for the benzyl alcohol oxidation, a number of different substrates were examined to test the generality of the AO-TEMPO packed-bed microreactor. High conversions were achieved when using both aromatic and aliphatic alcohols (Table 1, Entries 1–6). Secondary alcohols, which are known to

Chemoselective reduction of aldehydes by ruthenium trichloride and resin- bound formates

• Basudeb Basu,
• Bablee Mandal,
• Sajal Das,
• Pralay Das and
• Ashis K. Nanda

Beilstein J. Org. Chem. 2008, 4, No. 53, doi:10.3762/bjoc.4.53

• as hydrocarbons [4], primary and secondary alcohols [5][6], and formic acid and its salts [7][8][9][10][11] have been used as the hydrogen source. Besides the use of Rh, Ir, Ni and Pd metals in CTH, carbonyl reduction using the combination of Ru(II)-ligand complexes and propan-2-ol in the presence of

Synthesis of chiral cyclohexanes and carbasugars by 6-exo-dig radical cyclisation reactions

• Rajeev K. Shrivastava,
• Elise Maudru,
• Gurdial Singh,
• Richard H. Wightman and
• Keith M. Morgan

Beilstein J. Org. Chem. 2008, 4, No. 43, doi:10.3762/bjoc.4.43

• triphenylphosphine, imidazole and iodine in 78% yield. The iodides 26 were prone to rapid decomposition even when stored at 4 °C as evidenced by TLC and 1H, 13C NMR analysis. Similar chemistry was performed with aldehyde 21 which gave a mixture of secondary alcohols 23 in 71% yield and subsequently the mixture of

Large- scale ruthenium- and enzyme- catalyzed dynamic kinetic resolution of (rac)-1-phenylethanol

• Krisztián Bogár,
• Belén Martín-Matute and
• Jan-E. Bäckvall

Beilstein J. Org. Chem. 2007, 3, No. 50, doi:10.1186/1860-5397-3-50

• organic solvents.[38][39] CALB is immobilized on polyacrylate and this increases its thermostability and makes it easy to recover from the reaction mixture. Recently, we have developed highly efficient DKR protocols for secondary alcohols in which the traditional enzymatic resolution is combined with an

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

• stereoisomers of the epoxides 15[9] derived from 11 according to our reported procedure as synthetic intermediates. Regioselective cleavage of the epoxide (2R-[4S])-15 rings with lithium acetylide generated from 1-nonyne with n-butyl lithium in combination with BF3-Et2O[10] gave the secondary alcohols (2R-[4S

Conformational rigidity of silicon- stereogenic silanes in asymmetric catalysis: A comparative study

• Sebastian Rendler and
• Martin Oestreich

Beilstein J. Org. Chem. 2007, 3, No. 9, doi:10.1186/1860-5397-3-9

• reagents for the silicon-to-carbon chirality transfer. Kinetic resolution of secondary alcohols using a dehydrogenative coupling reaction. Catalytic cycle for hydrosilylation. Postulated catalytic cycle for dehydrogenative coupling. Supporting Information Supporting Information File 88: Supporting

Total syntheses of oxygenated brazanquinones via regioselective homologous anionic Fries rearrangement of benzylic O-carbamates

• Glaucia Barbosa Candido Alves Slana,
• Mariângela Soares de Azevedo,
• Rosângela Sabattini Capella Lopes,
• Cláudio Cerqueira Lopes and
• Jari Nobrega Cardoso

Beilstein J. Org. Chem. 2006, 2, No. 1, doi:10.1186/1860-5397-2-1

• , [12] the benzoylbenzofurans 5a-5d, were prepared in one-pot reaction from α-bromoacetophenone 6 and ortho-hydroxybenzaldehydes 7a-7d in excellent yields (90–96%). Reduction of benzoylbenzofurans 5a-5d in the presence of NaBH4 yielded the secondary alcohols 8a-8d, which upon treatment with N,N

Towards practical biocatalytic Baeyer- Villiger reactions: applying a thermostable enzyme in the gram- scale synthesis of optically- active lactones in a two-liquid- phase system

• Frank Schulz,
• François Leca,
• Frank Hollmann and
• Manfred T. Reetz

Beilstein J. Org. Chem. 2005, 1, No. 10, doi:10.1186/1860-5397-1-10

• of tolerance towards organic solvents. We speculated that thermostable alcohol dehydrogenases may meet these demands and decided to use the secondary alcohol dehydrogenase (2°ADH) from Thermoanaerobacter ethanolicus.[51][52][53][54][55][56] This 2°ADH oxidizes secondary alcohols like isopropanol to