HWE reaction with a variety of α,β-unsaturated aldehydes gave high conversion to diene amides. Subsequent [4+2] cycloaddition with 4-substituted urazines gave triazolopyridazines upon cleavage from resin. An alternate [4+2] cycloaddition method with urazine followed by a Mitsunobu reaction also provided triazolopyridazines.
使用[4 + 2]环加成策略完成了三唑并
哒嗪的固相文库合成。Horner-Wadsworth-Emmons(HWE)试剂
二乙基膦酰
乙酸被连接到Rink酰胺固相肽合成支持物的
氨基酸N端。与各种α,β-不饱和醛的HWE反应可高度转化为二烯酰胺。随后与4-取代的尿
嘧啶的[4 + 2]环加成反应在从
树脂上裂解后得到三唑并
哒嗪。尿
嘧啶的另一种[4 + 2]环加成方法,然后进行Mitsunobu反应,也提供了三唑并
哒嗪。