<i>In Situ</i> Dehydrogenative Generation of Vinyl Groups Bound to Heteroatoms by the Use of Ethyl Groups as Surrogates in Iridium-Catalyzed Intramolecular C–H/C–H Coupling
作者:Kaito Yagi、Toshimichi Ohmura、Michinori Suginome
DOI:10.1021/acscatal.3c05965
日期:2024.2.2
methoxy, and dimethylamino groups, were tolerated under the reaction conditions, whereas a cyano group induced DHA. The C(sp3)–H/C(sp3)–H dehydrogenative cyclization was applicable to ethyl 2-methylphenyl sulfide, N-ethyl-2-methylaniline, and ethyl(2-methylphenyl)silane, by which S-, N-, and Si-containing five-membered rings were constructed. In addition to a 2-methyl group on the aromatic rings, 2-tert-butyl
乙基2-甲基苯基醚直接转化为2-甲基苯并呋喃是通过铱催化剂系统促进的C(sp 3 )–H/C(sp 3 )–H脱氢环化实现的,使用DTBM-SEGPHOS ( L1 )作为配体和叔丁基醚-丁基乙烯(TBE)作为氢清除剂。该反应通过乙氧基脱氢 (DH) 形成乙烯基氧基,随后芳环上的 2-甲基通过分子内 C(sp 3 )–H 加成到乙烯基氧基上。脱氢芳氧基化 (DHA) 是烷基芳基醚催化 C(sp 3 )–H 转化的竞争过程,芳环 6 位取代基的存在可有效抑制脱氢芳氧基化 (DHA)。芳香环上的官能团,包括B(pin)、α-苯乙烯基、乙酰基、苯乙酰基、氟基、三氟甲基、甲氧基和二甲氨基,在反应条件下是可以耐受的,而氰基则诱导DHA。 C(sp 3 )–H/C(sp 3 )–H脱氢环化适用于乙基2-甲基苯基硫醚、N-乙基-2-甲基苯胺和乙基(2-甲基苯基)硅烷,其中S -, N构建了-、和含Si的