The synthesis and evaluation of an N-heterocyclic carbene (NHC)-capped cyclodextrin with various protecting groups were conducted. The corresponding gold complexes catalyzed the stereoselective cycloisomerization of enynes. Permethylation of the cyclodextrin’s hydroxyl groups improved yield and selectivity compared to its benzylated counterpart. Notably, alternating methyl and benzyl groups on the secondary rim of the cyclodextrin further enhanced asymmetry, achieving even higher enantioselectivities. To synthesize this compound, we optimized the selective deprotection of all benzyl groups at the 2-position of the sugar residues in the cyclodextrin.

中文翻译：

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ICyD 配体次缘的取代模式影响立体选择性


对具有各种保护基团的 N-杂环卡宾 （NHC） 封端环糊精进行了合成和评价。相应的金配合物催化乙烯的立体选择性环异构化。与苄基化对应物相比，环糊精羟基的过甲基化提高了产量和选择性。值得注意的是，环糊精次级边缘的甲基和苄基交替进一步增强了不对称性，实现了更高的对映选择性。为了合成这种化合物，我们优化了环糊精中糖残基 2 位上所有苄基的选择性脱保护。