Synthesis of adamantane derivatives. LVIII. Reaction of 1-adamantyl chloride with some heterocyclic unsaturated silanes.
作者:TADASHI SASAKI、AKIRA NAKANISHI、MASATOMI OHNO
DOI:10.1248/cpb.30.2051
日期:——
Various silylated heterocycles having amide functionality were treated with 1-adamantyl chloride (1) in the presence of a Lewis acid to give the corresponding N-adamantylated heterocycles. If α-position to the reacting lactim nitrogen was substituted, the reaction no longer occurred, or the adamantylation occurred at the position other than the expected nitrogen. These facts are attributed to a steric blocking effect of the α-substituent. While the same treatment of the thioamide 46 gave the S-adamantylated product, 48 and 51 afforded in contrast the N- and S-adamantylated products, respectively ; this result can be explained in terms of steric effect. Analogously, silylated 2-pyrazolines and triazoles were adamantylated at nitrogen. The reactions of 2-trimethylsilylthiophene, furan and -pyridine with 1 failed to give site-selective monoadamantylation.
在路易斯酸存在下,用 1-金刚烷酰氯(1)处理各种具有酰胺官能团的硅烷化杂环,得到相应的 N-金刚烷化杂环。如果反应的内酰胺氮的α位被取代,则不再发生反应,或者在预期氮以外的位置发生金刚烷基化反应。这些情况都归因于 α 取代基的立体阻滞效应。同样处理硫代酰胺 46 得到的是 S-金刚烷化产物,而 48 和 51 则分别得到了 N-和 S-金刚烷化产物;这一结果可以用立体效应来解释。类似地,硅烷化的 2-吡唑和三唑也在氮处发生了金刚烷化。2-三甲基硅基噻吩、呋喃和吡啶与 1 的反应未能产生位点选择性的单金刚烷化反应。