Vinylphosphonium and 2-aminovinylphosphonium salts – preparation and applications in organic synthesis

• Anna Kuźnik,
• Roman Mazurkiewicz and
• Beata Fryczkowska

Beilstein J. Org. Chem. 2017, 13, 2710–2738, doi:10.3762/bjoc.13.269

• the stereoselective synthesis thereof. The intermolecular Wittig reaction of these salts 58 with glyoxylic acid esters gave a dextro or levo γ-aminobutyric acid with values of specific rotation +14° and −6°, respectively, depending on the kind of chiral substituent R1 that was used (Scheme 39) [51]. γ

• -pyrrolocarbaldehyde. Stereoselective synthesis of bicyclic 2-pyrrolidinone derivatives in the reaction of vinylphosphonium halides and 5-acetyl-2-pyrrolidinone. Stereoselective synthesis of 3-pyrroline derivatives in the intramolecular Wittig reaction from vinylphosphonium salts and nitrogen nucleophiles. Synthesis

• vinylphosphonium salts with cyclic diketoester. Synthesis of quinoline derivatives in the intramolecular Wittig reaction from 2-(2-acylphenylamino)vinylphosphonium salts. Stereoselective synthesis of γ-aminobutyric acid in the intermolecular Wittig reaction from chiral 2-aminovinylphosphonium bromides and

Recent progress in the racemic and enantioselective synthesis of monofluoroalkene-based dipeptide isosteres

• Myriam Drouin and
• Jean-François Paquin

Beilstein J. Org. Chem. 2017, 13, 2637–2658, doi:10.3762/bjoc.13.262

• . This was then converted into a protected amino group employing a Mitsunobu reaction. Finally, removal of the nosyl group, followed by hydrolysis using lithium hydroxide, afforded the targeted isostere 24. Sano and co-workers also worked on the Mg(II)-promoted stereoselective synthesis of (Z

• (Cbz)-ψ[(Z)-CF=CH]-Lys(Cbz) [49] and Fmoc-Orn(Ns)-ψ[(Z)-CF=CH]-Nal were obtained [50]. Fujii and co-workers also worked on the stereoselective synthesis of (E)-monofluoroalkenes (Scheme 17) [51]. To obtain a good selectivity towards the (E)-alkene, they relied on the copper-mediated reduction and the α

• ]-Pro by Sano and co-workers. Synthesis of Cbz-Gly-ψ[(Z)-CF=C]-Pro by Sano and co-workers. Stereoselective synthesis of Fmoc-Gly-ψ[(Z)-CF=CH]-Phe by Pannecoucke and co-workers. Ring-closure metathesis to prepare Gly-ψ[(E)-CF=CH]-Phg by Couve-Bonnaire and co-workers. Stereoselective synthesis of Fmoc-Gly

Homologated amino acids with three vicinal fluorines positioned along the backbone: development of a stereoselective synthesis

• Raju Cheerlavancha,
• Ahmed Ahmed,
• Yun Cheuk Leung,
• Aggie Lawer,
• Qing-Quan Liu,
• Marina Cagnes,
• Hee-Chan Jang,
• Xiang-Guo Hu and
• Luke Hunter

Beilstein J. Org. Chem. 2017, 13, 2316–2325, doi:10.3762/bjoc.13.228

Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles

• Johannes Schörgenhumer,
• Maximilian Tiffner and
• Mario Waser

Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170

• -Chlorinations The stereoselective synthesis of chiral α-chlorinated carbonyl compounds is an important topic, since these targets can be valuable intermediates for the synthesis of a variety of different biologically active molecules [85][86]. The main interest in these compounds comes from their versatility

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

A concise and practical stereoselective synthesis of ipragliflozin L-proline

• Shuai Ma,
• Zhenren Liu,
• Jing Pan,
• Shunli Zhang and
• Weicheng Zhou

Beilstein J. Org. Chem. 2017, 13, 1064–1070, doi:10.3762/bjoc.13.105

• 10.3762/bjoc.13.105 Abstract A concise and practical stereoselective synthesis of ipragliflozin L-proline was presented starting from 2-[(5-iodo-2-fluorophenyl)methyl]-1-benzothiophene and 2,3,4,6-tetra-O-pivaloyl-α-D-glucopyranosyl bromide without catalyst via iodine–lithium–zinc exchange. The overall

• yield was 52% in three steps and the product purity was excellent. Two key diastereomers were prepared with efficient and direct access to the α-C-arylglucoside. Keywords: arylzinc derivative; β-C-arylglucoside; diastereomer impurity; ipragliflozin L-proline; stereoselective synthesis; Introduction

• canagliflozin. But so far, it has not been found that this method was applied to synthesize 1. In this paper, we report an efficient and practical method for the preparation of 1 through an arylzinc reagent. Results and Discussion Herein, a concise and practical stereoselective synthesis of 1 with three steps

A strategic approach to [6,6]-bicyclic lactones: application towards the CD fragment of DHβE

• Tue Heesgaard Jepsen,
• Emil Glibstrup,
• François Crestey,
• Anders A. Jensen and
• Jesper Langgaard Kristensen

Beilstein J. Org. Chem. 2017, 13, 988–994, doi:10.3762/bjoc.13.98

• synthetic procedures are extremely scarce. Herein, we wish to provide different strategies used to synthesize the CD fragment of DHβE as a general and simple method for the construction of [6,6]-bicyclic lactones which includes a stereoselective synthesis of vinyl halides, a regio- and stereoselective

• the C ring by an intramolecular Mizoroki–Heck cross-coupling reaction from a Z-configured olefin which would be crucial to the stereochemical outcome of the Heck cyclization event. We envisioned a Z-stereoselective synthesis of a vinyl halide [17] which should secure the desired E-stereochemistry for

Total synthesis of TMG-chitotriomycin based on an automated electrochemical assembly of a disaccharide building block

• Yuta Isoda,
• Norihiko Sasaki,
• Kei Kitamura,
• Shuji Takahashi,
• Sujit Manmode,
• Naoko Takeda-Okuda,
• Jun-ichi Tamura,
• Toshiki Nokami and
• Toshiyuki Itoh

Beilstein J. Org. Chem. 2017, 13, 919–924, doi:10.3762/bjoc.13.93

• afforded TMG-chitotriomycin (1) in 21% yield (10 steps from disaccharide 5bβ) [31]. Conclusion In conclusion, we have achieved the stereoselective synthesis of TMG-chitotriomycin (1) based on the automated electrochemical assembly of disaccharide and monosaccharide building blocks. Thus-obtained

Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems

• Katarina Kemper,
• Max Hirte,
• Markus Reinbold,
• Monika Fuchs and
• Thomas Brück

Beilstein J. Org. Chem. 2017, 13, 845–854, doi:10.3762/bjoc.13.85

• - and workup-intensive metal-organic catalysts [13][14][15][16]. The work of McKerrall et al. on ingenol [17][18] sets an example for the difficulty of stereoselective synthesis of complex diterpenes. Additionally, semi-synthetic approaches are tainted with the equivalent issues of economic efficiency

• stereoselective synthesis of (1R,3E,7E,11S,12S)-3,7,18-dolabellatriene, a bicyclic diterpene (Scheme 2). Dollabellanes derive mostly from marine organisms and display bioactivities such as antiviral and cytotoxic effects [59]. Dolabellatriene from a reprogrammed CotB2 contribute with antimicrobial activity

Silyl-protective groups influencing the reactivity and selectivity in glycosylations

• Mikael Bols and
• Christian Marcus Pedersen

Beilstein J. Org. Chem. 2017, 13, 93–105, doi:10.3762/bjoc.13.12

• proposed by Woerpel for these types of reactions [49]. Yamada and collaborators were the first to show that this principle could be used for the stereoselective synthesis of O-glycosides [42]. They prepared thioglucosides 60–62 (Scheme 11) having 2,3,4-O-TIPS groups and either TIPS, benzyl or pivaloyl

Strategies in asymmetric catalysis

• Tehshik P. Yoon

Beilstein J. Org. Chem. 2017, 13, 63–64, doi:10.3762/bjoc.13.8

• reactions. Those of us with research interests in stereoselective synthesis lauded this award because it celebrated the creative insights of these pioneers in asymmetric catalysis and because it marked a general recognition that enantioselective catalysis has had a significant practical impact on the

cis-Diastereoselective synthesis of chroman-fused tetralins as B-ring-modified analogues of brazilin

• Dimpee Gogoi,
• Runjun Devi,
• Pallab Pahari,
• Bipul Sarma and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2016, 12, 2816–2822, doi:10.3762/bjoc.12.280

• [2,1-c]chromen-6a-ols 5 (Figure 1) as B-ring-modified analogues of brazilin through the fusion of chroman and tetralin motifs to generate new bioactive molecules. To the best of our knowledge, the stereoselective synthesis of such chroman-fused tetralins has never been reported. Based on the continuous

• convenient Brønsted acid-catalyzed, metal-free, stereoselective synthesis of 6a,7,8,12b-tetrahydro-6H-naphtho[2,1-c]chromen-6a-ols as B-ring-modified analogues of brazilin using starting materials derived from inexpensive 1-tetralone and phenol derivatives. Our worries concerning the formation cis–trans

Useful access to enantiomerically pure protected inositols from carbohydrates: the aldohexos-5-uloses route

• Felicia D’Andrea,
• Giorgio Catelani,
• Lorenzo Guazzelli and
• Venerando Pistarà

Beilstein J. Org. Chem. 2016, 12, 2343–2350, doi:10.3762/bjoc.12.227

• the stereoselective synthesis of enantiopure inositol derivatives, also the possibility to pick and tag specific positions of the inositol ring, installing the protective groups earlier on the carbohydrate frame through the well-known sugar chemistry, is of extreme interest. Although some attractive

A new and expeditious synthesis of all enantiomerically pure stereoisomers of rosaprostol, an antiulcer drug

• Wiesława Perlikowska,
• Remigiusz Żurawiński and
• Marian Mikołajczyk

Beilstein J. Org. Chem. 2016, 12, 2234–2239, doi:10.3762/bjoc.12.215

• ; stereoselective synthesis; synthetic design; Introduction Rosaprostol (1) is a trade name for 7-(2-hexyl-5-hydroxycyclopentane)heptanoic acid (Figure 1) which belongs to a series of 19,20-dinorprostanoic acid derivatives. It exhibits gastric antisecretory activity and cytoprotective action without the undesired

• stereoselective synthesis of rosaprostols 1a–d. The resolution of (±)-3 and some experimental details are depicted in Scheme 3. It shows also the absolute configurations of (+)-3 and (−)-3 ascribed to the compounds based on their successful conversion into the known rosaprostols 1a and 1c, respectively. Having

Stereoselective synthesis of fused tetrahydroquinazolines through one-pot double [3 + 2] dipolar cycloadditions followed by [5 + 1] annulation

• Xiaofeng Zhang,
• Kenny Pham,
• Shuai Liu,
• Marc Legris,
• Alex Muthengi,
• Jerry P. Jasinski and
• Wei Zhang

Beilstein J. Org. Chem. 2016, 12, 2204–2210, doi:10.3762/bjoc.12.211

• formaldehyde through [5 + 1] annulation to afford a novel polycyclic scaffold bearing tetrahydroquinazoline, pyrrolidine, pyrrolidinedione, and N-substituted maleimide in stereoselective fashion. Keywords: [5 + 1] annulation; [3 + 2] cycloaddition; one-pot reactions; stereoselective synthesis

The direct oxidative diene cyclization and related reactions in natural product synthesis

• Juliane Adrian,
• Leona J. Gross and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2016, 12, 2104–2123, doi:10.3762/bjoc.12.200

• of this polyketide. At this point it has to be mentioned that in 1987 the group of Weiler also used such a permanganate-promoted oxidative cyclization for the stereoselective synthesis of the THF unit in ionomycin [63]. Similarly, in 1980 Walba et al. reported on the B/C-ring fragment synthesis of

• ) was found to be more potent than rollidecin D (70) with selectivity toward the colon cell line HT-29 [108]. In 2001, the groups of Sinha and Keinan reported on a stereoselective synthesis of rollidecin C (69) and D (70) [109] using the tandem oxidative polycyclization reaction with trifluoro

• ], another triterpene natural product found in Jamaican endemic plant Spathelia glabrescens (Rutaceae) [141]. In 1999, Morimoto and co-workers reported on a stereoselective synthesis of the meso-tris-THF natural product teurilene (82) [142][143] (several previous total syntheses existed [144][145][146][147

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

• used by Orena in reactions with cyclopentadiene and cyclohexadiene, giving the products with de values of 74 and 86%, respectively [118]. A series of chiral auxiliaries based on mandelic acid showed similar stereoselectivity benefits and have been proposed by Procter for stereoselective synthesis [109

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• stereoselective synthesis of 1,2-dihydroquinolin-2-ylphosphonates 271 and 1,2-dihydroisoquinolin-1-ylphosphonates 272 via the three-component reactions of quinoline or isoquinoline, dialkyl acetylenedicarboxylates 269, and dialkyl phosphonates 270 has been described by Shaabani et al. (Scheme 56) [94]. The

• -(aminothioxomethyl)-1,2-dihydroisoquinolin-1-yl]phosphonates. Three-component stereoselective synthesis of 1,2-dihydroquinolin-2-ylphosphonates and 1,2-dihydroisoquinolin-1-ylphosphonates. Diphosphorylation of diazaheterocyclic compounds via a tandem 1,4–1,2 addition of dimethyl trimethylsilyl phosphite

• proline with aldehydes and dialkyl phosphites for the synthesis of pyrrolidinylphosphonates. Three-component domino aza-Wittig/phospha-Mannich sequence for the phosphorylation of isatin derivatives. Stereoselective synthesis of phosphorylated trans-1,5-benzodiazepines via a one-pot three-component

Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups

• Jakub Saadi,
• Christoph Bentz,
• Kai Redies,
• Dieter Lentz,
• Reinhold Zimmer and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2016, 12, 1236–1242, doi:10.3762/bjoc.12.118

Conjugate addition–enantioselective protonation reactions

• James P. Phelan and
• Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

• researchers have developed methods for the stereoselective synthesis of tertiary carbon stereocenters. One aesthetically pleasing approach is the enantioselective protonation of prochiral enolates and enolate equivalents [1][2][3][4][5][6][7][8][9][10]. While an attractive strategy, the enantioselective

Modular synthesis of the pyrimidine core of the manzacidins by divergent Tsuji–Trost coupling

• Sebastian Bretzke,
• Stephan Scheeff,
• Felicitas Vollmeyer,
• Friederike Eberhagen,
• Frank Rominger and
• Dirk Menche

Beilstein J. Org. Chem. 2016, 12, 1111–1121, doi:10.3762/bjoc.12.107

• . Application of the concept for manzacidin core synthesis After proofing the general adaptability of our synthetic concept, we next evaluated the applicability of this procedure for the synthesis of the authentic manzacidin substrate. As shown in Scheme 5, we first focused on the stereoselective synthesis of

• urea-type cyclization precursor 19. Stereodivergent synthesis of 1,3-syn- and anti-tetrahydropyrimidinones [31]. Stereoselective synthesis of all possible stereoisomers of the manzacidin core amine by asymmetric addition to chiral tert-butanesulfinyl ketimines. Synthesis of the authentic cyclization

Towards the total synthesis of keramaphidin B

• Pavol Jakubec,
• Alistair J. M. Farley and
• Darren J. Dixon

Beilstein J. Org. Chem. 2016, 12, 1096–1100, doi:10.3762/bjoc.12.104

• wish to report our preliminary synthetic efforts towards the stereoselective synthesis of the heavily functionalised piperidine core of keramaphidin B (1). Results and Discussion Our overall synthetic strategy is presented in Figure 2. We envisaged that a late stage alkyne RCM reaction of 2 and cis

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

A convenient route to symmetrically and unsymmetrically substituted 3,5-diaryl-2,4,6-trimethylpyridines via Suzuki–Miyaura cross-coupling reaction

• Dariusz Błachut,
• Joanna Szawkało and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2016, 12, 835–845, doi:10.3762/bjoc.12.82

• approach in the determination of the enantiomeric purity of (+)-crispine [81] and (R)-(+)-harmicine after their stereoselective synthesis [82]. The results of a more detailed study on the stereochemistry of atropisomeric enantiomers will be published elsewhere. Conclusion Herein, we described an easy and

Opportunities and challenges for direct C–H functionalization of piperazines

• Zhishi Ye,
• Kristen E. Gettys and
• Mingji Dai

Beilstein J. Org. Chem. 2016, 12, 702–715, doi:10.3762/bjoc.12.70

• the diamine switch strategy and α-methylbenzyl chiral auxiliary strategy has been reported to give the best results and produce 51 in 70% yield and 90:10 diastereoselectivity (Figure 11, reaction 3). O’Brien and co-workers also reported a stereoselective synthesis of enantiopure 2,6-trans- and 2,5