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。
A Method for Pyrrole Synthesis through Intramolecular Cyclization of γ-Alkynyl Oximes Promoted by SmI2
作者:Songlin Zhang、Yiqiong Wang、Lingyu Zhang
DOI:10.1055/a-1932-5749
日期:2022.12
A new strategy for the synthesis of pyrrole through intramolecular cyclization of γ-alkynyl oximes promoted by SmI2 is reported for the first time. In contrast to the prior methods, the selection of oxime instead of oximeether or ester as substrate makes the synthetic method without accompaniment of organic waste (ArCO2H, AcOH, or ROH) because the hydroxyl group in oxime acts as the leaving group
Selective electrophilic cyclization of <i>ortho</i>-carbonylarylacetylenols for the synthesis of cyclopenta[<i>a</i>]naphthalenol and 2-phenylnaphthalen-1-ol analogs
Selective cyclization occurred when the reaction was conducted in methyl trimethylacetate solvent which predominantly produced the 2-phenylnaphthalen-1-ol product through 6-endo-dig cyclization without elimination or the formation of cyclopenta[a]naphthalenol via shutting down the 5-exo-dig mode of cyclization. Switching the acid from a Brønsted acid to Bi(OTf)3 led to smooth reactions, providing
这项工作展示了一种通过选择性环化合成环戊[ a ]萘酚和2-苯基萘-1-醇类似物的新方法。采用邻炔基芳基烯酮作为常见底物,可以通过 2-卤代芳基苯乙酮和 pent-4-yn-1-ol 衍生物之间的 Sonogashira 偶联来制备。这些前体无需纯化即可通过在加热条件下用(+)-CSA处理来构建2-苯基萘-1-醇中间体。当反应在三甲基乙酸甲酯溶剂中进行时,发生选择性环化,该溶剂主要通过 6-内位环化产生 2-苯基萘-1-醇产物,而没有消除或通过关闭 5-外位环化形成环戊[ a ]萘酚。挖掘环化模式。将酸从布朗斯台德酸转换为 Bi(OTf) 3导致反应顺利,以中等至良好的产率提供环戊[ a ]萘酚产物。此外,我们还展示了利用2-苯基萘-1-醇制备萘醌,萘醌是生物活性和天然产物化合物的重要核心结构。
K<sub>2</sub>CO<sub>3</sub>-Mediated Cyclization and Rearrangement of γ,δ-Alkynyl Oximes To Form Pyridols
A novel K2CO3-mediated cyclization and rearrangement of γ,δ-alkynyl oximes for the synthesis of pyridols is described. The process accomplishes an efficient [1,3] rearrangement of the O-vinyl oxime intermediate which is in situ generated from the intramolecular nucleophilic addition of γ,δ-alkynyl oximes. The reaction employs readily accessible starting materials, tolerates a wide range of functional
描述了一种新颖的K 2 CO 3介导的γ,δ-炔基肟的环化和重排,用于合成吡咯。该方法完成了O-乙烯基肟中间体的有效[1,3]重排,该中间体是由γ,δ-炔基肟的分子内亲核加成反应原位产生的。该反应采用容易获得的起始原料,耐受各种官能团,并以高收率得到各种合成上具有挑战性的吡咯。
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