Vinyl Selenones Derived from d‐Fructose: A New Platform for Fructochemistry

Abstract

d-Fructose, an inexpensive biomass precursor available on al arge scale, has been used for the generation of enantiomerically pure chemical entities. Construction of vinyl selenone moieties on cyclic skeletons of d-fructose led to the highly reactive synthetic intermediates comprisingo f an electron-deficient double bond along with an excellent leaving group. Reactions of these Michael acceptors with dif-ferent nucleophiles afforded aziridines, thiiranes,c yclopropanes, dihydrofurans, dihydroisoxazole, dibenzyloxymethylfuran, and isonucleosides in moderate to good yields. This powerful and practical route provides an ew platform for synthetic applicationso fr enewable biomass precursors and adds to the toolbox for chemists interested in new chemical entities. Supportinginformation for this article can be found under http:// dx.doi.org/10.1002/ajoc.201600183.I tc ontains 1 Ha nd 13 CNMR spectra of all new compounds, COSYs pectra( for 18 b, 20 a, 24,a nd 27 c), NOESY spectrum(for 17 c), 1D NOE difference spectra (for 18 b, 20 a,and 24), and ORTEP diagrams (for 15 h, 17 a, 22,and 30 b).populara ldoses such as d-glucose, d-mannose, d-ribose, dxylose, etc. Ac hiral ketones ynthesized from d-fructose [9] rapidly developed into an ew class of asymmetric epoxidation catalyst forthe epoxidation of olefins ( Figure 2). [10] Fructose-derived chiral 1,3-oxazolidine-2-thiones (OZTs) are also used as chiral substrates in coupling reactions ( Figure 2). [11] 1,5-Anhydro-dfructose( 1,5-AnFru) [12] and di-d-fructose dianhydrides (DFAs) [2, 13] are important precursors for the synthesis of new carbohydrate derivatives (Figure 2).We have been designing methodsf or accessing enantiopure oxaheterocycles, [14] carbocycles, [15, 16] aza-and thia-heterocycles, [16, 17] pyrroles, [18] and 1,5-disubstituted-1,2,3-triazoles [19] from monosaccharides. In line with the utilization of sugar molecules as "chiral pools"i ns ynthetic chemistry, [20] our strategy wast ou se highlyr eactive vinyl sulfone-and vinyl sulfoxide-modified carbohydrates, [21] which are powerful Michael acceptors ande fficient partners in cycloaddition reactions. [15, 19] More recently,w eh ave introduced vinyl selenone-modified carbohydrates as efficient Michael acceptors in diversity oriented synthesis (DOS) to generate complex molecular scaffolds. [22] The aryl selenoyl functionality of vinyl selenone plays ad ual role as an efficient electron-withdrawing group as well as al eaving group, allowing Michael addition followed by elimination in tandem fashion. [22] Although vinyl selenones are widely used in simple systems [23] and nucleosides, [24] vinyl selenones derived from carbohydrates have rarely been utilized partly because of the notoriously unpredictable stability of carbohydrate selenones or selenoxides. [25,26] Nevertheless,w e have designed and used stable vinyl selenone-modified furanosides for generating new molecules. [22,26] As d-fructose is now considered as an intermediate for generating small molecules such as 2,5-dimethylfuran, 5-hydroxymethy...

Modern Synthetic Strategies with Organoselenium Reagents: A Focus on Vinyl Selenones

“…The combination of the chirality of carbohydrates with the high reactivity of vinyl selenones can offer interesting opportunities for generating new stereochemically defined and structurally complex compounds. Recently, Pathak designed D -xylose or D -fructose-derived alkenyl selenones to explore Michael-initiated functionalizations of sugars [ 40 , 41 ] with small carbo and heterocyclic rings. Moreover, furanoside and pyranoside rings were decorated with five-membered N-heteroaromatic compounds through Michael addition/elimination sequences.…”

Vinylation of N-Heteroarenes through Addition/Elimination Reactions of Vinyl Selenones

“…Both contain an electron-withdrawing group that activates the double bond to the conjugate nucleophilic attack, but the weak C–Se bond donates to the phenylselenonyl moiety a better leaving group character for further substitution or elimination reactions. While several Michael addition/cyclization cascade reactions using vinyl selenones are widely reported in the literature [ 29 , 30 , 31 ], also in asymmetrical versions [ 32 , 33 , 34 , 35 , 36 , 37 ], only sporadic examples involving addition/elimination domino processes are investigated [ 38 , 39 ].…”