Palladium-catalyzed C–H glycosylation and retro Diels–Alder tandem reaction via structurally modified norbornadienes (smNBDs)

Abstract

This report describes palladium catalyzed C-H glycosylation and retro Diels-Alder tandem reaction via structurally modified norbornadiene (smNBDs). The smNBDs was proposed to regulate the reactivity of aryl-norbornadiene-palladacycle (ANP) process, as...

Visible-Light-Induced Copper-Catalyzed Asymmetric C(sp3)–C(sp3)–H Glycosylation: Access to C-Glycopeptides

“…2 Recent studies in this field have focused on the direct C(sp 3 )−C(sp 2 )−H/C(sp)−H glycosylation (Scheme 1, path a). 3 Palladium-catalyzed C−H glycosylation has emerged as a powerful way to obtain C-branched chain glycosides, especially involving directed and nondirected group-assisted methods. Other strategies for the construction of C−C glycosidic bonds were established by C(sp 2 )−C(sp 3 )/C-(sp 2 )−H glycosylation (Scheme 1, path b).…”

“…Intermediate IV experienced a H shift to produce species V. Subsequent intramolecular recombination of alkyl radicals with Cu II promoted the formation of chiral Cu III species VI. Finally, the target C(sp 3 )−C(sp 3 )−H glycosylation Scheme 3. Substrate Scope a,b,c a Reaction conditions: 1a (2 equiv, 0.2 mmol), 2a (1 equiv, 0.1 mmol), L1 (0.012 mmol, 0.12 equiv), Cu(OTf) 2 (0.1 equiv, 0.01 mmol), DABCO (1.5 equiv, 0.15 mmol), argon atmosphere, 15 h, −10 °C, and under 440 nm blue LED.…”

Ruthenium‐Catalyzed Stereo‐ and Site‐Selective ortho‐ and meta‐C−H Glycosylation and Mechanistic Studies

“…Thereafter, we treated the reaction with ethylene dithioglycol and boron trifluoride diethyl ether and performed a deprotection experiment on 3a to obtain glycosides containing multiple naked hydroxyl groups in one step [27] (Scheme 3).…”

Recent Advances in the Synthesis of Five‐membered Nitrogen Heterocycles Induced by Palladium Ions and Complexes

“…This Pd/NBD cooperative catalysis led to the formation of glycosylated indoles. [91] Glycosylation was performed by reacting 2-iodoanilines and glycosyl chlorides in the presence of TFP ligand L4 and Ts-NBD as coupling partner. In the process, first substituted norbornadiene served as the coupling partner in the Catellani reaction to induce ortho-CÀ H glycosylation followed by a retro Diels-Alder tandem reaction.…”

“…In fact, there is only a single example using NBD substituted with a para ‐toluenesulfonyl group. This Pd/NBD cooperative catalysis led to the formation of glycosylated indoles [91] . Glycosylation was performed by reacting 2‐iodoanilines and glycosyl chlorides in the presence of TFP ligand L 4 and Ts‐NBD as coupling partner.…”