Base-Promoted Tandem Cyclization for the Synthesis of Benzonitriles by C−C Bond Construction
作者:Cheng-Zhi Zhu、Yin Wei、Min Shi
DOI:10.1002/adsc.201701329
日期:2018.2.15
A facile synthesis of benzonitriles via a base‐promoted tandem cyclization reaction of α,β‐unsaturated enones having electron‐withdrawing group (EWG) and 2‐acyl‐acrylonitriles was developed. This new synthetic method to access benzonitriles is suitable for a wide range of substrates. A plausible reaction mechanism is proposed on the basis of previous literature and our own investigations.
Aldol Condensation of Aldehydes with Ketones Promoted by the Copper(II) Ion. Orientation to the Chemical Model for Metalloaldolases
作者:Masaaki Iwata、Sakae Emoto
DOI:10.1246/bcsj.49.1369
日期:1976.5
condensation reactions of aromaticaldehydes such as 1 through 4 and 7 through 13, and aliphatic aldehydes such as 5 and 6, with a number of ketones promoted by the copper(II) ion were examined. The reactions were specifically promoted by the copper(II) ion, while such metal ions as zinc, cobalt(II), manganese(II), and magnesium were quite inactive as catalysts. All the aldehydes but 7 and 8 reacted with
研究了芳香醛(例如 1 到 4 和 7 到 13)和脂肪醛(例如 5 和 6)与许多由铜 (II) 离子促进的酮的羟醛缩合反应。铜 (II) 离子特别促进了反应,而锌、钴 (II)、锰 (II) 和镁等金属离子作为催化剂非常不活泼。在 Claisen-Schmidt 类型的反应中,除 7 和 8 之外的所有醛都与除乙酰乙酸乙酯、乙腈和硝基甲烷以外的所有脂肪族酮反应不同程度。乙酰丙酮得到Knoevenagel类型的缩合产物。在醛与 2-丁酮的反应中,醛会区域特异性地攻击 2-丁酮 C3 处的亚甲基。胺类抑制反应,同时观察到锌或钴 (II) 的共存效应。结果表明,在铜(II)离子促进的反应中,存在的底物选择性很大程度上取决于酮的种类。结果,可能...
Asymmetric Retro-Claisen Reaction Catalyzed by Chiral Aza-Bisoxazoline–Zn(II) Complex: Enantioselective Synthesis of α-Arylated Ketones
作者:Jia-Hui Liu、Xue-Jiao Lv、Yan-Kai Liu
DOI:10.1021/acs.orglett.3c00372
日期:2023.3.17
been developed under the catalysis of a chiral aza-bisoxazoline–Zn(II) complex. The reaction proceeds via a sequence of conjugate addition, arylation, hemiketal anion-initiated C–C bond cleavage, and enantioselective protonation of enolate to provide various functionalized α-arylated ketones bearing a tertiary stereogenic center with high enantioselectivities. Notably, biologically important benzofuran