A Lewis-base-catalyzed enantioselective [3 + 3] annulation reaction of Morita−Baylis−Hillman (MBH) carbonates with α-arylidene pyrazolinones is described, affording the pyrazolone-fused spirocyclohexenes bearing an all-carbon quaternary stereocenter in high yields with good to excellent diastereoselectivities and excellent enantioselectivities.

An unprecedented [4 + 3] annulation reaction of aza- ortho-quinone methides with arylcarbohydrazonoyl chlorides has been achieved under mild conditions. The annulation underwent a sequential conjugate addition/intramolecular annulation/rearrangement, providing a useful method for the synthesis of biologically interesting 2,3-dihydro-1 H-benzo[ e][1,2,4]triazepine.

A visible‐light‐promoted iterative synthesis of 2‐deoxyoligosaccharides is reported by De‐Cai Xiong, Xin‐Shan Ye, and co‐workers in their Research Article (e202114726). The rapid constructions of oligosaccharides, 20‐mer deoxyglycan, and digoxin are facilitated by a bromide‐based hydrogen species through an electron transfer process.

An enantioselective synthesis of biologically important imidazolidines has been achieved via a tandem [3 + 2] cycloaddition/1,4-addition reaction of azomethine ylide and aza-o-quinone methides. With the use of this tool, various imidazolidine derivatives are obtained in good yields with excellent diastereoselectivities and enantioselectivities.

C-Glycosides are a class of carbohydrates with a variety of biological activities, and the construction of their unique C-C glycosidic bond is a hot and challenging topic in carbohydrate chemistry. The formation of new C-C bond from carbon-carbon double bond is a common strategy in organic chemistry. With the rapid development of ene-chemistry, great progress in the synthesis of C-glycosides from glycal donors containing 1,2-double bond has been made. In this review, the methods for the synthesis of C-glycosides based on glycals are summarized, including Ferrier I-type C-glycosylation, Heck-type C-glycosylation, C-glycosylation of 1-substituted glycals using transition metal-catalyzed coupling reaction, Michael-type C-glycosylation of 2-substituted glycals, and radical addition type C-glycosylation of glycals. Keywords glycal; C-glycoside; C-glycosylation; carbohydrate 碳苷是指糖上端基碳原子和配糖体通过碳-碳键相 连的糖类化合物. 自然界存在的天然碳苷化合物多具有 重 要 的 生 理 活 性 . 假 尿 嘧 啶 核 苷 [1] (pseudouridine) (Scheme 1)是第一个被报道的碳核苷. 它被认为是 tRNA 降解的最终产物, 在肿瘤患者体内含量会异常增高, 可 以作为肿瘤标志物. 从中药葛根中分离得到的异黄酮类 碳苷葛根素 [2] (puerarin), 具有舒张血管、缓解心绞痛等 多种活性. 很多具有重要生理活性的天然产物也含有碳 苷单元, 比如 Kendomycin [3] . 与氧苷的 C-O 键相比, 碳苷端基的 C-C 键对酶和化学(酸)水解有更强的耐受 性. 例如, α-半乳糖神经酰胺 KRN7000 的碳苷类似物对 小 鼠 B16 黑色 素瘤 细胞的 保护 作用比 其氧 苷母体 KRN7000 强 1000 倍 [4] ; 由根皮苷(phlorizin)改造后的碳