Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

• Valerian Dragutan,
• Ileana Dragutan,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68

• method, an enyne precursor was first converted into an exocyclic 1,3-diene in 92% yield. A Diels–Alder reaction with naphthoquinone and a deprotection step then led to the final compound (−)-zenkequinone B in a stereoselective manner (Scheme 23). C-Aryl glycosides Another interesting report from

• Kaliappan et al. [93] described a highly efficient synthesis of C-aryl glycosides, which are naturally occurring compounds of biological relevance. Starting from a glycoside precursor, the intermolecular enyne metathesis with ethylene gas in the presence of the second-generation Grubbs catalyst allowed the

• ). Subsequent Diels–Alder cycloaddition reactions with dienophiles and further aromatization reactions paved the way for a convenient access to structurally diverse polycyclic compounds. For instance, installing the C-aryl and spiro-C-aryl glycosides in the same moiety was successfully achieved. An application

Anomeric modification of carbohydrates using the Mitsunobu reaction

• Julia Hain,
• Patrick Rollin,
• Werner Klaffke and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1619–1636, doi:10.3762/bjoc.14.138

• phenols to achieve aryl glycosides Not only anomeric esters, but also glycosides can be obtained through the Mitsunobu reaction. Dehydrative glycosylation approaches with reducing sugars were previously reviewed [43][44]. As phenols are weak acids, they are suitable reaction partners in the Mitsunobu

• reaction, leading to aryl glycosides with reducing sugars as the alcohol components. Grynkiewicz can be called the pioneer of Mitsunobu glycosylation, as having explored the Mitsunobu reaction for the synthesis of various aryl glycosides [24][45]. Thus, native sugars such as D-glucose and D-mannose (Scheme

• photoswitchable azobenzene α-D-mannoside 47 (Scheme 9) [46]. Notably, in this reaction, traces of an anomeric mixture of the respective furanoside 48 were detected. The Mitsunobu synthesis of aryl glycosides was also applied to p-nitrophenol [47], naphthols [48][49], or multifunctional phenols [27][50]. Such

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

• A. Michael Downey and
• Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123

• . 5.1.1 Accessing phenolic glycosides: To the best of our knowledge the first example of this methodology was applied to the synthesis of phenolic glycosides by Grynkiewicz [103][104] nearly 40 years ago. In his seminal work he discovered that by using a more reactive phosphine (PBu3), aryl glycosides

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

• prepare dapagliflozin and canagliflozin. However, these approaches might be difficult to scale up because of the involvements of complex synthetic procedures, chromatographic purification or expensive catalysts and ligands. Gong et al. [15] reported an approach to synthesise C-aryl glycosides based on a

Synthesis of rigid p-terphenyl-linked carbohydrate mimetics

• Maja Kandziora and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 1749–1758, doi:10.3762/bjoc.10.182

• . Unnatural divalent rigid p-terphenyl-linked C-aryl glycosides with 2.0 nm dimension are available using Suzuki cross-couplings. The key compound, a p-bromophenyl-substituted 1,2-oxazine, was prepared by a stereoselective [3 + 3]-cyclization of a D-isoascorbic acid-derived (Z)-nitrone and lithiated TMSE

• synthesis of divalent compounds 1 with p-terphenyl spacers and of β-D-2-aminotalose- or β-D-2-aminoidose-configured carbohydrate mimetics 2 (Scheme 1). These novel carbohydrate mimetics represent unique structures, combining the features of C-aryl-glycosides and aminosugars. The p-bromophenyl-substituted

• intermediates such as 15 or 16 are also useful precursors for the synthesis of other C-aryl glycosides with potential biological activity. By simple hydrogenolysis of the bicyclic compounds, three new aminopyrans could be synthesized. Different methods for N–O bond cleavage like palladium-catalyzed

Synthesis and structure of tricarbonyl(η⁶-arene)chromium complexes of phenyl and benzyl D-glycopyranosides

• Thomas Ziegler and
• Ulrich Heber

Beilstein J. Org. Chem. 2012, 8, 1059–1070, doi:10.3762/bjoc.8.118

• hydrogen bonds. Keywords: aryl glycosides; carbohydrates; transition-metal complex; tricarbonyl(arene)chromium; Introduction In 1957, Fischer and Öfele published the preparation of tricarbonyl(η6-benzene)chromium, which was the first arene tricarbonylchromium complex [1]. Since then, a plethora of

2-Allylphenyl glycosides as complementary building blocks for oligosaccharide and glycoconjugate synthesis

• Hemali D. Premathilake and
• Alexei V. Demchenko

Beilstein J. Org. Chem. 2012, 8, 597–605, doi:10.3762/bjoc.8.66

• efforts were of particular relevance. First, chemists have been making aryl glycosides for some 130 years [28], and many excellent protocols for their synthesis are available [29]. We determined that AP glycosides can be readily obtained from the corresponding peracetate by using inexpensive 2-allylphenol