Jurczak Janusz, Sobczuk Adam, Da Browa Kajetan, Lindner Marcin, Niedbała Patryk
Institute of Organic Chemistry , Polish Academy of Sciences , Kasprzaka 44/52 , 01-224 Warsaw , Poland.
J Org Chem. 2018 Nov 2;83(21):13560-13567. doi: 10.1021/acs.joc.8b02160. Epub 2018 Oct 23.
A new protocol for PTC-mediated O-alkylation of the intraannular position of 20-membered unclosed cryptands (UCs) is reported. In contrast to the classical, "direct" strategy, which requires functionalization of the lariat arm at the beginning of synthesis, this "indirect" approach enables the late-stage introduction of various benzylic substituents after an unfavorable macrocyclization step (11 examples, yields up to 98%). Notably, this method permits preparation of, previously inaccessible, crowded UCs bearing 1-acetylpyrene substituent and dimer joined by p-xylene linker.
报道了一种用于20元非封闭穴醚（UCs）内环位置的相转移催化（PTC）介导的O-烷基化新方案。与经典的“直接”策略不同，后者在合成开始时就需要对套索臂进行官能化，这种“间接”方法能够在不利的大环化步骤之后后期引入各种苄基取代基（11个实例，产率高达98%）。值得注意的是，该方法能够制备以前无法获得的带有1-乙酰基芘取代基且通过对二甲苯连接体连接的二聚体的拥挤UCs。
