Gold-Catalyzed Diastereoselective Cycloisomerization of Alkylidene-Cyclopropane-Bearing 1,6-Diynes
作者:Hongchao Zheng、Laura L. Adduci、Ryan J. Felix、Michel R. Gagné
DOI:10.1002/anie.201405147
日期:2014.7.21
AbstractAn unprecedented gold‐catalyzed diastereoselective cycloisomerization of 1,6‐diynes bearing an alkylidene cyclopropane moiety has been developed. This methodology enables rapid access to a variety of 1,2‐trimethylenenorbornanes, which are important building blocks in the preparations of abiotic and sesquiterpene core structures.
Regioselective Crossed Aldol Reactions under Mild Conditions via Synergistic Gold-Iron Catalysis
was identified as an essential co-catalyst in preventing vinyl Au protodeauration and facilitating nucleophilic additions. Effective C–C bond formation was achieved undermildconditions (room temperature) with excellent regioselectivity and high efficiency (1% [Au], up to 95% yields). The intramolecular reaction was also achieved, giving successful macrocyclization (16–31 ring sizes) with excellent
开发了一种协同金铁 (Au-Fe) 催化系统,用于顺序炔烃水合和乙烯基 Au 加成至醛或酮。 Fe(acac) 3被认为是防止乙烯基 Au 原型脱气和促进亲核加成的重要助催化剂。在温和条件(室温)下实现了有效的 C-C 键形成,具有出色的区域选择性和高效率(1% [Au],产率高达 95%)。还实现了分子内反应,成功进行了大环化(16-31 个环尺寸),且收率优异(高达 90%,克级),无需进一步稀释 (0.2 M),这突显了这种新的交叉羟醛策略在挑战中的巨大潜力。目标分子合成。
Alkyne Trifunctionalization via Divergent Gold Catalysis: Combining π-Acid Activation, Vinyl–Gold Addition, and Redox Catalysis
Here we report the first example of alkyne trifunctionalization through simultaneous construction of C–C, C–O, and C–N bonds via goldcatalysis. With the assistance of a γ-keto directing group, sequential gold-catalyzed alkynehydration, vinyl–gold nucleophilic addition, and gold(III) reductive elimination were achieved in one pot. Diazonium salts were identified as both electrophiles (N source) and