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。
Pd(0)-Catalyzed Conjugate Addition of Benzylzinc Chlorides to α,β-Enones in an Atmosphere of Carbon Monoxide: Preparation of 1,4-Diketones
作者:Motoki Yuguchi、Masao Tokuda、Kazuhiko Orito
DOI:10.1021/jo035468+
日期:2004.2.1
Pd(0)-catalyzed conjugate addition of benzylzinc chloride to methyl vinyl ketone in the presence of chlorotrimethylsilane and lithium chloride in an atmosphere of carbon monoxide at room temperature afforded 1-phenyl-2,5-hexanedione monosilyl enol ether. In this catalytic carbonylation, four components are connected in one reaction. Successive acidic workup generated a variety of 1,4-diketones from
Conjugate addition of α-boron-stabilized carbanions is an underexplored reaction modality. Existing methods require deborylation of geminal di-/triboryl alkanes and/or the presence of additional activating groups. We report the 1,4-addition of α,α-diboryl carbanions generated via deprotonation of the corresponding geminal diborons. The methodology provided a general route to highly substituted and
2-Methylfurans were prepared by an effective cyclization of 1-alkyn-5-ones in the presence of mercuric triflate as the catalyst under very mild reaction conditions with high catalytic turnover up to 100 times. Benzene, toluene, or dichloromethane was the solvent of choice.