Convenient phosphorus tribromide induced syntheses of substituted 1-arylmethylnaphthalenes from 1-tetralone derivatives
摘要:
A series of 1-arylmethylnaphthalenes 7a-g and I I have been synthesized conveniently in good yields at room temperature through phosphorus tribromide induced aromatization of 1-aryl-[3,4]-dihydronaphthyl-methanols 6a-g and 10, which were obtained from 1-tetralone derivatives. (c) 2005 Elsevier Ltd. All rights reserved.
l-Proline derived nitrogenous steroidal systems: an asymmetric approach to 14-azasteroids
作者:Ritesh Singh、Gautam Panda
DOI:10.1039/c3ra42272k
日期:——
intramolecular SN2′ cyclization reaction for the construction of critical C-ring in the nitrogen impregnated steroidal architectures bearing unsaturation at Δ9(11) position. In the endeavour to synthesize some new congeners, the remote electronic impact of the electron donating groups in A ring and heteroatoms like oxygen in Bring, on the propensity of C-ring cyclization was also observed.
已经描述了在温和的反应条件下使用L-脯氨酸来访问14-氮杂类固醇的有效手性池方法。关键步骤涉及分子内的S N 2'环化反应,以在含氮的甾族结构中在Δ9 (11)位置携带不饱和键,以构建关键的C环。为了合成一些新的同类物,还观察到了A环上给电子基团和B环上的氧等杂原子对C环环化倾向的远程电子影响。
Multimetallic Ni- and Pd-Catalyzed Cross-Electrophile Coupling To Form Highly Substituted 1,3-Dienes
作者:Astrid M. Olivares、Daniel J. Weix
DOI:10.1021/jacs.7b13601
日期:2018.2.21
synthesis of highly substituted 1,3-dienes from the coupling of vinyl bromides with vinyl triflates is reported for the first time. The coupling is catalyzed by a combination of (5,5'-bis(trifluoromethyl)-2,2'-bipyridine)NiBr2 and (1,3-bis(diphenylphosphino)propane)PdCl2 in the presence of a zinc reductant. This method affords tetra- and penta-substituted 1,3-dienes that would otherwise be difficult
Regioselective Synthesis of Vinyl Halides, Vinyl Sulfones, and Alkynes: A Tandem Intermolecular Nucleophilic and Electrophilic Vinylation of Tosylhydrazones
作者:Devi Prasan Ojha、Kandikere Ramaiah Prabhu
DOI:10.1021/ol503114n
日期:2015.1.2
in tandem at the carbene center to install an electrophile and a nucleophile on the same carbon. This metal-free concept, which is unprecedented, has been illustrated by regioselectivesynthesis of a variety of vinyl halides, vinyl sulfones, and alkyne derivatives.
Synthesis of α,ω‐Bis‐Enones by the Double Addition of Alkenyl Grignard Reagents to Diacid Weinreb Amides
作者:Stefan Wiesler、Michael A. Bau、Thomas Niepel、Sara L. Younas、Hieu‐Trinh Luu、Jan Streuff
DOI:10.1002/ejoc.201901043
日期:2019.9.30
The synthesis of bis‐enones from alkenyl bromides and α,ω‐bis‐Weinreb amides via a double Grignard reaction is reported. The work contains reliable protocols for the double addition and the efficient generation of the required substituted alkenyl Grignard reagents from alkenyl bromide precursors.
Rhodium-Catalyzed Enantioselective Intramolecular Hydroacylation of Trisubstituted Alkenes
作者:Kirsten F. Johnson、Eugene A. Schneider、Brian P. Schumacher、Arkady Ellern、Joseph D. Scanlon、Levi M. Stanley
DOI:10.1002/chem.201603880
日期:2016.10.24
We report the first examples of transition metal‐catalyzedenantioselective alkene hydroacylations with 1,1,2‐trisubstituted alkenes. DFT and mechanistic studies are consistent with a reaction pathway for these rhodium‐catalyzed processes including intramolecular alkene hydroacylation and α‐epimerization to generate highly enantioenriched, polycyclic architectures. This reaction sequence enables the