Selective carboxylation of reactive benzylic C–H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system

• Toshifumi Dohi,
• Shohei Ueda,
• Kosuke Iwasaki,
• Yusuke Tsunoda,
• Koji Morimoto and
• Yasuyuki Kita

Beilstein J. Org. Chem. 2018, 14, 1087–1094, doi:10.3762/bjoc.14.94

• determined to be the best in terms of product yield. No reaction was observed in the absence of sodium bromide (Table 1, entry 9) and other representative hypervalent iodine(III) reagents, such as PIFA and PhI(OH)OTs, and pentavalent Dess–Martin periodinane and IBX, were inferior for this carboxylation when

Hypervalent iodine-mediated Ritter-type amidation of terminal alkenes: The synthesis of isoxazoline and pyrazoline cores

• Sang Won Park,
• Soong-Hyun Kim,
• Jaeyoung Song,
• Ga Young Park,
• Darong Kim,
• Tae-Gyu Nam and
• Ki Bum Hong

Beilstein J. Org. Chem. 2018, 14, 1028–1033, doi:10.3762/bjoc.14.89

• -iodoxybenzoic acid) and DMP (Dess–Martin periodinane) (Table 1, entries 7 and 8) gave similar yields to the background reaction. Lastly, a Lewis acid screen (Table 1, entries 9–12) was performed. Among the tested Lewis acids, AlCl3, SnCl4, TiCl4, TMSOTf and BF3·Et2O, the latter was found to be the best choice

2-Iodo-N-isopropyl-5-methoxybenzamide as a highly reactive and environmentally benign catalyst for alcohol oxidation

• Takayuki Yakura,
• Tomoya Fujiwara,
• Akihiro Yamada and
• Hisanori Nambu

Beilstein J. Org. Chem. 2018, 14, 971–978, doi:10.3762/bjoc.14.82

• oxidants have been widely employed for oxidation in organic synthesis [1][2][3][4][5][6][7][8][9] because they are nonmetallic, less toxic, and easy to handle, and they allow mild reaction conditions in most cases. Pentavalent iodine reagents such as Dess–Martin periodinane (DMP, 1) [10] and 2

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

Synthesis of ribavirin 2’-Me-C-nucleoside analogues

• Fanny Cosson,
• Aline Faroux,
• Jean-Pierre Baltaze,
• Jonathan Farjon,
• Régis Guillot,
• Jacques Uziel and
• Nadège Lubin-Germain

Beilstein J. Org. Chem. 2017, 13, 755–761, doi:10.3762/bjoc.13.74

• ketone with Dess–Martin periodinane afforded 12a in 87% yield whereas the reaction of the less reactive isomer 11b led to 12b in 44% yield. With the aim to get some explanations for the different reactivities observed for the two isomers 10a and 10b, we investigated the structure of the less reactive

Exploring endoperoxides as a new entry for the synthesis of branched azasugars

• Svenja Domeyer,
• Mark Bjerregaard,
• Henrik Johansson and
• Daniel Sejer Pedersen

Beilstein J. Org. Chem. 2017, 13, 644–647, doi:10.3762/bjoc.13.63

• –Doering oxidation conditions [15]. However, when the same conditions were applied to alcohol 4 it resulted in a complex mixture. Other oxidation procedures, including TPAP [16], Dess–Martin periodinane [17] and TEMPO [18] were attempted but in all instances complex mixtures were obtained and none of the

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• the corresponding hydroxamic acids using, for example, periodate [14], Dess–Martin periodinane [64], Swern oxidation conditions [65], lead and silver oxide [66], and transition-metal oxidation with peroxide as the oxidant [67]. In a recent work by Tusun dirhodium caprolactamate [68], and the aerobic

Selective bromochlorination of a homoallylic alcohol for the total synthesis of (−)-anverene

• Frederick J. Seidl and
• Noah Z. Burns

Beilstein J. Org. Chem. 2016, 12, 1361–1365, doi:10.3762/bjoc.12.129

• avoided exposure to strong bases or reducing agents, a limitation that significantly guided the choice of reagents and conditions for the subsequent steps. Dess–Martin periodinane oxidation of alcohol 6 followed by Horner–Wadsworth–Emmons olefination with triethyl 2-phosphonopropionate (9) furnished the

• equiv), acetone, 65 °C, 3 h; c) Dess–Martin periodinane (1.2 equiv), NaHCO3 (5 equiv), CH2Cl2, 0 °C to rt; d) triethyl 2-phosphonopropionate 9 (1.5 equiv), n-BuLi (1.2 equiv), 1:1 THF/acetonitrile, 0 °C, 5 min; e) DIBAL−H (3 equiv), CH2Cl2, −78 °C, 20 min; f) NBS (1.2 equiv), ClTi(OiPr)3 (1.1 equiv), 20

• mol % Ti(OiPr)4, 10 mol % (S,R)-4, 0.025 M hexanes, −15 °C, 42 h; g) Dess–Martin periodinane (1.2 equiv), NaHCO3 (5 equiv), CH2Cl2, 0 °C to rt; h) CBr4 (2 equiv), PPh3 (4 equiv), CH2Cl2, 0 °C, 10 min; i) Et3N (5 equiv), dimethyl phosphonate (4 equiv), DMF, rt, 5 min. Optimization of a selective

A cross-metathesis approach to novel pantothenamide derivatives

• Jinming Guan,
• Matthew Hachey,
• Lekha Puri,
• Vanessa Howieson,
• Kevin J. Saliba and
• Karine Auclair

Beilstein J. Org. Chem. 2016, 12, 963–968, doi:10.3762/bjoc.12.95

• molecule to be extended to pantothenamide 16. As outlined in Scheme 3, 16 was assembled from 11d by first oxidation to the corresponding aldehyde 12 using Dess–Martin periodinane in wet DCM. Further oxidation to the carboxylic acid 13 was achieved using mild chlorite oxidation. The product was used in the

Stereoselective synthesis of hernandulcin, peroxylippidulcine A, lippidulcines A, B and C and taste evaluation

• Marco G. Rigamonti and
• Francesco G. Gatti

Beilstein J. Org. Chem. 2015, 11, 2117–2124, doi:10.3762/bjoc.11.228

• to −30 °C). Treatment of 7 with Dess–Martin periodinane (DMP) [23] in CH2Cl2 at room temperature gave ketone 8 ([α]D +11.0° (c 1.0, CHCl3)) in 90% yield. The most difficult step of this synthetic route is the dehydrogenation of ketone 8. Since our main interest is focused on the taste evaluation of

Total synthesis of panicein A₂

• Lili Yeung,
• Lisa I. Pilkington,
• Melissa M. Cadelis,
• Brent R. Copp and
• David Barker

Beilstein J. Org. Chem. 2015, 11, 1991–1996, doi:10.3762/bjoc.11.215

• minutes, giving 14 in an excellent 94% yield. Hydrogenolysis of the alkene in 14 using Pd/C in MeOH proceeded in 2 hours, providing alcohol 15 which was then oxidised to the desired ketone 13 with Dess–Martin periodinane in 75% yield over two steps. Although this approach was ultimately two steps longer

Towards inhibitors of glycosyltransferases: A novel approach to the synthesis of 3-acetamido-3-deoxy-D-psicofuranose derivatives

• Maroš Bella,
• Miroslav Koóš and
• Chun-Hung Lin

Beilstein J. Org. Chem. 2015, 11, 1547–1552, doi:10.3762/bjoc.11.170

• ). Subsequently, the selective protection of the primary hydroxy group in diol 5 as trityl ether under standard conditions followed by the oxidation of the free secondary hydroxy group in 3-acetamido-3-deoxy-4,5-O-isopropylidene-6-O-pivaloyl-1-O-trityl-D-altritol (6) with Dess–Martin periodinane yielded a

Articulated rods – a novel class of molecular rods based on oligospiroketals (OSK)

• Pablo Wessig,
• Roswitha Merkel and
• Peter Müller

Beilstein J. Org. Chem. 2015, 11, 74–84, doi:10.3762/bjoc.11.11

• /PPh3. vii: Cu/C, Et3N. viii: K2CO3/MeOH. ix: CBr4/PPh3/NaN3). Macrocyclization of articulated rod 25. Synthesis of building blocks 27–29 (i: 1. pyrene-1-ylacetic acid, DCC/DMAP, 68%; 2. Dess–Martin periodinane 89%. ii: 1. cinnamoyl chloride, iPr2NEt, 94%; 2. Dess–Martin periodinane, 86%. iii: K2CO3

• –Martin-periodinane. iii: pentaerythritol, pTsOH (cat.). iv: 2-(4-methoxybenzyloxy)acetic acid, DCC, HOBt. v: (COCl)2/DMSO. vi: NaH, TMSCl, TMSOTf, vii DDQ, DCM, buffer pH 7). Synthesis of articulated rod 11 (i: CBr4, PPh3, NaN3. ii: K2CO3/MeOH. iii: Cu/C DCM/MeOH 1:1, cat. Et3N). Sequential deprotection

• ); 0.013 % (w/v) (line 3) and 0.02 % (w/v) (line 4) at 37 °C. Comparison of photochemical reactivity of 32b, 33a, 39 (left). Irradiation UV spectrum of 32b in ACN (right, t = 0, 0.5, 1, 1.5, 2.5, 4, 8, 16 min). Synthesis of building block 8 (i: trimethylsilylpropargyl-4-nitrophenylcarbonate. ii: Dess

NAA-modified DNA oligonucleotides with zwitterionic backbones: stereoselective synthesis of A–T phosphoramidite building blocks

• Boris Schmidtgall,
• Claudia Höbartner and
• Christian Ducho

Beilstein J. Org. Chem. 2015, 11, 50–60, doi:10.3762/bjoc.11.8

• some modifications were applied (Scheme 3). Starting from 2'-deoxyadenosine (22), N-6-benzoyl-5'-O-TBDMS-2'-deoxyadenosine (23) was prepared [61] and subjected to oxidation of the 3'-hydroxy functionality to a keto group with Dess–Martin periodinane (DMP). This was followed by reduction with sodium

Palladium-catalysed cyclisation of alkenols: Synthesis of oxaheterocycles as core intermediates of natural compounds

• Miroslav Palík,
• Jozef Kožíšek,
• Peter Koóš and
• Tibor Gracza

Beilstein J. Org. Chem. 2014, 10, 2077–2086, doi:10.3762/bjoc.10.216

• –Martin periodinane, CH2Cl2, 0 °C, 1 h. L-DET = L-dimethyl tartrate. Synthesis of alkenols 24–26 and 28. Reagents and conditions: a) lit. [32] DIBAL-H, CH2Cl2; b) TBDPSCl, imidazole, CH2Cl2, rt, overnight; c) NaH, THF then MeI, rt, overnight; d) FeCl3·6H2O, CHCl3, rt, 1 h (for 25); e) 60% AcOH, 60 °C, 3 h

• ]. Synthesis of alkenols 20-23 and 30. Reagents and conditions: a) lit. [31] (COCl)2, DMSO, Et3N, CH2Cl2, −78 °C to rt, 2 h; b) Phosphonium salt, BuLi, THF, 0 °C to rt, overnight, MPLC; c) lit. [32] (EtO)2POCH2CO2Et, NaH, THF, 0 °C to rt, 3 h; d) 60% AcOH, 60 °C, 3 h; e) MeMgCl, Et2O, 0 °C to rt, 1 h; f) Dess

Syntheses of ¹⁵N-labeled pre-queuosine nucleobase derivatives

• Jasmin Levic and
• Ronald Micura

Beilstein J. Org. Chem. 2014, 10, 1914–1918, doi:10.3762/bjoc.10.199

• work-up and reversed-phase column chromatography (C18) (Scheme 2) [14]. Then, the α-bromo aldehyde 7 was obtained in two steps from commercially available 3-phthalimidopropan-1-ol that was oxidized using Dess–Martin periodinane. Subsequent in situ bromination of the 3-phthalimidopropan-1-al with

• chromatography, 92%. Compound 2 was isolated as salt of trifluoroacetic acid (TFA). Synthesis of [H215N(C7')] preQ1 base (3). a) K2CO3 (1.5 equiv), DMF, 70 °C, 14 h, 47%. b) Dess–Martin periodinane (1.5 equiv), CH2Cl2, 3 h, room temperature. c) 5,5-dibromobarbituric acid (0.6 equiv), acetonitrile, reflux, 2 h

Application of cyclic phosphonamide reagents in the total synthesis of natural products and biologically active molecules

• Thilo Focken and
• Stephen Hanessian

Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195

• converted to the corresponding sulfonamide with para-methoxyphenyl (PMP) sulfonyl chloride. Cleavage of the silyl ether moiety with TBAF gave primary alcohol 143, which was oxidized to the corresponding acid 144 by a two-step protocol consisting of treatment with Dess–Martin periodinane followed by Pinnick

• primary alcohol of the side chain was oxidized with Dess–Martin periodinane (DMP) to give aldehyde 183. The latter was subsequently reacted with trimethylsilyl ketene acetal 184 in the presence of oxazaborolidinone 185 to afford aldol product 186 and the C22-epimer as only isomers in a 1:1 mixture. Dess

Olefin cross metathesis based de novo synthesis of a partially protected L-amicetose and a fully protected L-cinerulose derivative

• Bernd Schmidt and
• Sylvia Hauke

Beilstein J. Org. Chem. 2014, 10, 1023–1031, doi:10.3762/bjoc.10.102

• and acetal cleavage, giving 4-benzoyl protected L-amicetose 16 as an anomeric mixture in 65% yield (Scheme 3). With a view towards L-cinerulose, formally the C4-oxidation product of L-amicetose, we started from cross metathesis product 8 which was first oxidized using Dess–Martin periodinane [69]. The

Asymmetric total synthesis of a putative sex pheromone component from the parasitoid wasp Trichogramma turkestanica

• Danny Geerdink,
• Jeffrey Buter,
• Teris A. van Beek and
• Adriaan J. Minnaard

Beilstein J. Org. Chem. 2014, 10, 761–766, doi:10.3762/bjoc.10.71

• allylic alcohol 17 in 90% yield, which in turn was oxidized to aldehyde 18 using Dess–Martin periodinane. Given that the conversion of 18 into 19 using a Wittig reaction had proven to be sluggish, we switched again to a Horner–Wadsworth–Emmons olefination, expecting to observe high E-selectivity. Indeed

Synthesis of complex intermediates for the study of a dehydratase from borrelidin biosynthesis

• Frank Hahn,
• Nadine Kandziora,
• Steffen Friedrich and
• Peter F. Leadlay

Beilstein J. Org. Chem. 2014, 10, 634–640, doi:10.3762/bjoc.10.55

• -dicyano-1,4-benzoquinone, Men = (l)-menthyl, DMP = Dess–Martin periodinane, TMS = trimethylsilyl. Synthesis of the BorDH3 substrates. a) Thiophenolpropionate, Cy2BCl, Me2EtN, Et2O, −78 °C to −20 °C, 16 h (57% over two steps from 12); b) HSNAc, Et3N, DMF, rt, 16 h (70%); c) THF/HCOOH/H2O (6:3:1), rt, 2 d

Synthesis of the B-seco limonoid core scaffold

• Hanna Bruss,
• Hannah Schuster,
• Rémi Martinez,
• Markus Kaiser,
• Andrey P. Antonchick and
• Herbert Waldmann

Beilstein J. Org. Chem. 2014, 10, 194–208, doi:10.3762/bjoc.10.15

• achieved under acidic conditions. Oxidation of the resulting diol with Dess–Martin periodinane and subsequent Pinnick oxidation completed the synthesis. Ireland–Claisen rearrangements with fully decorated A ring. With the suitable substituted fragment 87 in hand, we decided to initially perform the

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• (295 to 296, see Scheme 37) has been investigated early on by the group of Boeckmann [217]. Dess–Martin periodinane oxidation of diol 306 resulted in a smooth rearrangement at ambient temperature, yielding formyldihydrooxepine 307. A modified approach has been investigated by the group of Lee, using

Total synthesis of the endogenous inflammation resolving lipid resolvin D2 using a common lynchpin

• John Li,
• May May Leong,
• Alastair Stewart and
• Mark A. Rizzacasa

Beilstein J. Org. Chem. 2013, 9, 2762–2766, doi:10.3762/bjoc.9.310

• the ylide derived from 9 provided the alkene 10 [9] with excellent stereoselectivity. Oxidation of 10 with Dess–Martin periodinane then afforded aldehyde 7. The phosphonium salt 6 [21][22] was produced from propargyl bromide via silylation of the derived sodium salt with TIPSCl followed by reaction

Multigramme synthesis and asymmetric dihydroxylation of a 4-fluorobut-2E-enoate

• James A. B. Laurenson,
• John A. Parkinson,
• Jonathan M. Percy,
• Giuseppe Rinaudo and
• Ricard Roig

Beilstein J. Org. Chem. 2013, 9, 2660–2668, doi:10.3762/bjoc.9.301

• one-pot oxidation/Wittig procedure was implemented from 37a; treatment with the Dess–Martin periodinane [41] in the presence of the stabilised ylide afforded a 4:1 E:Z mixture of the product alkene 39a in good (74%) yield. A second purification by column chromatography isolated the E-alkene

The total synthesis of D-chalcose and its C-3 epimer

• Jun Sun,
• Song Fan,
• Zhan Wang,
• Guoning Zhang,
• Kai Bao and
• Weige Zhang

Beilstein J. Org. Chem. 2013, 9, 2620–2624, doi:10.3762/bjoc.9.296

• via TBSOTf to furnish 11, and 11 could be converted into 12 (Scheme 5). With requisite intermediate 12 in hand, our attention was directed toward preparing the final product, chalcose. Alcohol 12 was subjected to Dess–Martin periodinane [29] because it afforded aldehyde 13 in 86% yield, making it

• form 7′ using TBSOTf. Alcohol 8′ was oxidized using Dess–Martin periodinane to give aldehyde 9′ in 86% yield. Finally, 9′ was efficiently deprotected with TBAF, leading to the C-3 epimer of chalcose (I′) in 83% yield. Epimer I′ was acetylated using acetic anhydride in pyridine, furnishing diacetate 10

• -toluenesulfonate. Reagents and conditions: (a) TBSOTf, 2,6-lutidine, CH2Cl2, rt, 90%; (b) CSA, MeOH, 0 °C, 59%. TBS = t-butyldimethylsilyl, Tf = trifluoromethanesulfonyl, CSA = DL-10-camphorsulfonic acid. Reagents and conditions: (a) Dess–Martin periodinane, CH2Cl2, rt, 86%; (b) TBAF, THF, 0 °C, 84%; (c) Py, AcO2