Ph3PAuNTf2 (≈1 mol-%) catalyzes the selective cycloisomerization of substituted aryl propargyl ethers into 2H-chromenes in excellent yields. Benzofuran byproducts are formed only in the case of electron-deficient arenes, in up to 7 % relative yield. The Ph3PAuNTf2-catalyzed cyclization of aryl propargyl ethers was applied as a key step to the concise synthesis of the naturally occurring benzopyrans
Ph3PAuNTf2 (≈1 mol-%) 以优异的产率催化取代的芳基
炔丙基醚选择性环异构化成
2H-色烯。
苯并呋喃副产物仅在缺电子
芳烃的情况下形成,相对产率高达 7%。Ph3PAuNTf2 催化的芳炔基醚环化被用作简明合成天然苯并
吡喃 seselin、xaNThyletin、precocenes I 和 II、8-(3',3'-二甲基烯丙基)weNTeria chromene 和 2, 2-二甲基-8-
异戊二烯-6-
丙烯酸。