Synthesis of Bridged Benzazocines and Benzoxocines by a Titanium-Catalyzed Double-Reductive Umpolung Strategy
作者:Plamen Bichovski、Thomas M. Haas、Daniel Kratzert、Jan Streuff
DOI:10.1002/chem.201405852
日期:2015.2.2
A sequence of two titanium(III)‐catalyzed reductive umpolung reactions is reported that allows the rapid construction of benzazo‐ and benzoxozine building blocks. The first step is a reductive cross‐coupling of quinolones or chromones with Michael acceptors. This reaction proceeds with complete syn‐selectivity for the quinolone functionalization while the anti‐diastereomers are obtained as the major
A readily accessible and bench-stable water-soluble hypervalent iodine(III) reagent (phenyliodonio)sulfamate (PISA) with an I–N bond was synthesized, and its structure was characterized by X-ray crystallography. With PISA, various indoles were synthesized via C–H amination of 2-alkenylanilines involving an aryl migration/intramolecular cyclization cascade with excellent regioselectivity in aqueous
A Pd-catalyzed cascade Ullmann coupling–aldol–dehydration reaction of ortho-acylphenyl iodides affords colchino analogues with wide functional group tolerance.
Herein, we demonstrate Oxa‐Diels‐Alder reaction of 3‐trifluoroacetyl‐4‐methyl‐quinolin‐2(1H)‐one with aldehydes in the presence of a base to engineer the functionalized pyrano[3,4‐c]quinolones. This reaction proceeds through an in‐situ generated hetero dendralene intermediate and features perfect stereoselectivity on a wide range of substrates with excellent atom economy. The high electron‐withdrawing
Auto-Tandem Catalysis: Synthesis of Acridines by Pd-Catalyzed C=C Bond Formation and C(<i>sp<sup>2</sup></i>)-N Cross-Coupling
作者:Zhongxing Huang、Yang Yang、Qing Xiao、Yan Zhang、Jianbo Wang
DOI:10.1002/ejoc.201201070
日期:2012.10.10
A facilepalladium-catalyzedsynthesis of acridines has been realized by consecutive C=C double bondformation and C–N cross-coupling. A variety of functionalized acridines can be accessed from easily available o-dihalobenzenes and N-tosylhydrazones in a single operation. This one-pot protocol has a wide scope with respect to both coupling partners, and provides an efficient route to functionalized