Recent developments on the synthesis of functionalized carbohydrate/sugar derivatives involving the transition metal–catalyzed C–H activation/C–H functionalization

Creating, Preserving, and Directing Carboxylate Radicals in Ni-Catalyzed C(sp3)–H Acyloxylation of Ethers, Ketones, and Alkanes with Diacyl Peroxides

“…However, for α-HAT, the β-oxygen acts as a strong acceptor via a σ CH → σ* CO interaction that pulls electron density out of the α-CH bond making hydrogen less reactive toward the electron-deficient oxygen radical. Similar deactivating effects of the β-alkoxy substituent on C–H bonds were observed earlier in the Rh-catalyzed insertion into C–H bonds of ethers, a variety of transition metal-catalyzed C–H functionalizations of carbohydrates and radical C–H activation in diols …”

Construction of carbazole-based unnatural amino acid scaffolds via Pd(ii)-catalyzed C(sp3)–H functionalization

“…There stereochemistry of 18a and 18b was assigned based on earlier works. 3 The carbazole-based aliphatic carboxamide derivatives 18c , 18d / 18e , 18f , 18g , 18h , 18i and 18j were obtained from the corresponding aliphatic carboxamide substrates 3n , 3o , 3p , 3q , 3r , 3s and 3t containing the 8-aminoquinoline DG. Most of the corresponding amino acid carboxamide or aliphatic carboxamide substrates ( 3 ) used for performing the Pd( ii )-catalyzed, 8-aminoquinoline aided β-C–H arylation are known compounds and were prepared using standard methods.…”

“…Transition metal-catalyzed C–H activation and functionalization of small organic molecules is a remarkable transformation for installing functional groups at inactive C–H bonds. 1–4 In particular, the Pd( ii )-catalyzed, bidentate directing group-directed, site-selective functionalization of inactive C(sp 3 )–H bonds in organic compounds is emerging as an efficient method for constructing C–C bonds. This method has been applied for the diastereoselective functionalization of prochiral/diastereotopic C(sp 3 )–H bonds of various aliphatic and alicyclic compounds.…”

“…This method has been applied for the diastereoselective functionalization of prochiral/diastereotopic C(sp 3 )–H bonds of various aliphatic and alicyclic compounds. 1–5 Markedly, the synthesis of various unnatural amino acid derivatives has been reported by utilizing the Pd( ii )-catalyzed bidentate directing group-aided C(sp 3 )–H functionalization of carboxamides derived from α-amino acids and non-α-amino acids. 4,6…”

C–H modification of natural products: a minimalist enabling tactic for drug discovery, API processing and bioconjugation

“…14 The attractive features of these reactions are high atom- and step-economy and broad functional group accommodation, which have led to their increasing applications in complex synthetic endeavours, viz. natural product synthesis 15 and late stage derivatization of peptides, 16 nucleosides, 17 carbohydrates 18 and drug-like scaffolds. 19 In the present context, since C–H bonds in natural products rarely contribute to target binding, functionalization of such bonds presents minimum risk to their biological potencies.…”