A Scalable and Expedient Route to 1-Aza[6]helicene Derivatives and Its Subsequent Application to a Chiral-Relay Asymmetric Strategy
摘要:
A rapid route to diversely functionalized 1-aza[6]helicenes has been achieved via the development of a copper-mediated cross-coupling reaction, followed by PtCl4-catalyzed cycloisomerization. Not only does this method allow access to these functionally important molecules on gram scale, but this strategy Is also suitable for relaying the axial chirality of a key intermediate to the helicity of the product.
Enantioselective Synthesis of Fully Benzenoid Single and Double Carbohelicenes via Gold‐Catalyzed Intramolecular Hydroarylation
作者:Masakazu Satoh、Yu Shibata、Ken Tanaka
DOI:10.1002/chem.201800986
日期:2018.4.11
The enantioselectivesynthesis of fully benzenoid single and double carbo[6]helicenes has been achieved via the gold‐catalyzed intramolecular hydroarylation. The single crystal of the racemic double carbo[6]helicene consists of unique layer structureslike timbers with halving joints in the woodworking. Furthermore, the double carbo[6]helicenes exhibited relatively large CPL activities among chiral
The reaction of biphenyl-alkynes with in situ generated Tf2C=CH2 followed by neutralization gave polycyclicaromatichydrocarbons (PAHs) decorated by a highly stabilized carbanionic functionality. Thus obtained PAHs showed improved solubility in both aqueous and organic solvents.
的反应联苯炔烃与原位产生的TF 2 C = CH 2,然后中和,得到由高度稳定的负碳离子的功能的装饰多环芳香烃(PAHs)。由此获得的多环芳烃在水性和有机溶剂中均显示出改善的溶解度。
Intramolecular addition of benzyl anion to alkyne utilizing [1,2]-phospha-Brook rearrangement under Brønsted base catalysis
A novel reaction system for intramolecular addition of benzyl anions to alkynes was developed by utilizing the [1,2]-phospha-Brook rearrangement under Brønsted base catalysis. The present reaction is a rare example of a catalytic additionreaction of an unstabilized benzyl anion under Brønsted base catalysis.
Diisobutylaluminum Hydride Promoted Selectivity-Switchable Synthesis of Benzothiophene Oxides and Benzothiophenes via an Al–Li-Dimetalated Intermediate
We developed an efficient and direct method for synthesis of benzothiophene oxides from 1-bromo-2-[2-(trimethylsilyl)ethynyl]benzenes and thionylchloride as an easily accessible source of the sulfinyl group. Benzothiophenes were also synthesized selectively by simply increasing the amount of thionylchloride. These methods achieved efficient syntheses of various benzothiophene oxides and benzothiophenes
Synthesis of Phenanthrene Derivatives by Intramolecular Cyclization Utilizing the [1,2]-Phospha-Brook Rearrangement Catalyzed by a Brønsted Base
作者:Azusa Kondoh、Takuma Aoki、Masahiro Terada
DOI:10.1002/chem.201501377
日期:2015.9.1
The synthesis of functionalized phenanthrene derivatives was achieved by intramolecular cyclization utilizing the [1,2]‐phospha‐Brook rearrangement under Brønsted base catalysis. Treatment of biaryl compounds having an α‐ketoester moiety and an alkyne moiety at the 2 and 2′ positions, respectively, with diisopropyl phosphite in the presence of a catalytic amount of phosphazene base P2‐tBu provides
功能化的菲衍生物的合成是通过在Brønsted碱催化下利用[1,2]-磷-布鲁克重排进行分子内环化来实现的。在催化量的磷腈碱P2 - t Bu存在下,用亚磷酸二异丙酯处理在2和2'位置分别具有α-酮酸酯部分和炔烃部分的联芳基化合物,可以得到9,10-二取代的菲衍生物。高产。该反应涉及通过乌珀隆过程生成酯烯酸酯,即将亚磷酸二异丙酯添加至酮部分,然后进行[1,2]-磷-布鲁克重排,将分子内添加至炔烃,以及[3] ,3]以连续方式重新排列烯丙基磷酸酯部分。