描述了细菌代谢物 (+)-链霉素 A 的对映选择性合成,这是癌细胞中己糖激酶 II (HK2) 的新型抑制剂。其单甲基化间苯二酚对三联苯核可通过 Danheiser 苯环化方便地制备。其邻位喹啉手性中心的阐述是通过碘基促进的区域选择性和对映选择性羟基化脱芳构化来完成的。所得邻苯二酚的烯属侧链最终在瓦克型条件下氧化,生成(+)-链霉抗菌素A的丙酮附属物。
Enantioselective Prévost and Woodward reactions using chiral hypervalent iodine(iii): switchover of stereochemical course of an optically active 1,3-dioxolan-2-yl cation
Optically active 1,3-dioxolan-2-yl cation intermediates were generated during enantioselective dioxyacetylation of alkene with chiral hypervalent iodine(III). Regioselective attack of a nucleophile toward the intermediate resulted in reversal of enantioselectivity of the dioxyacetylation.
Amino acid-derived novel chiral hypervalent iodine(V) reagents were synthesized from the corresponding chiral iodoarenes through DMDO oxidations. Their oxidation states were determined by the 13C NMR chemical shifts of the ipso-carbon of the iodine atom, HRMS analysis, and elemental analyses. They were applied to the enantioselective hydroxylative dearomatization/[4+2]-dimerization cascade reactions
从相应的手性碘芳烃通过DMDO氧化合成了氨基酸衍生的新型手性高价碘试剂。它们的氧化态由碘原子的ipso-碳的13 C NMR化学位移,HRMS分析和元素分析确定。将它们用于苯酚衍生物的对映选择性羟基化脱芳香化/ [4 + 2]-二聚级联反应,得到所需产物,其ee最高为58%。
Forging Medium Rings via I(I)/I(III)‐Catalyzed Diene Carbofunctionalization
作者:You‐Jie Yu、Joel Häfliger、Zi‐Xuan Wang、Constantin G. Daniliuc、Ryan Gilmour
DOI:10.1002/anie.202309789
日期:2023.9.18
An I(I)/I(III) catalysis-based strategy to access 8-membered carbocycles via the direct carbofunctionalization of 2-phenethyl-substituted 1,3-dienes is disclosed. This strategy to generate densely functionalized, fluorinated benzocyclooctenes is modular and through changes in the oxidation/activation regime and the external nucleophile, the challenging cyclization can be merged with formation of allylic