Phosphine-Catalyzed Regioselective and Stereoselective Hydrohalogenation Reaction of 2-(1-Alkynyl)-2-alken-1-ones: Synthesis of 2-Halo-1,3-dienes
作者:Wenbo Li、Lihua Gao、Zhenting Yue、Junliang Zhang
DOI:10.1002/adsc.201500408
日期:2015.8.24
A triphenylphosphine (PPh3)‐catalyzed, regioselective and stereoselective hydrohalogenation reaction of 2‐(1‐alkynyl)‐2‐alken‐1‐ones with metal halides in the presence of acetic acid is described, furnishing functionalized 3,4‐disubstituted 2‐halo‐1,3‐dienes in moderate to good yields with high stereoselectivity and regiospecificity. The simple execution, mild conditions and the potential utilization
Visible light catalyzed reaction of α-bromochalcones with chalcones: direct access to the urundeuvine scaffold
作者:Bhupal Singh Karki、Mukund M. D. Pramanik、Ruchir Kant、Namrata Rastogi
DOI:10.1039/c8ob01881b
日期:——
The α-keto vinyl radicals generated from α-bromochalcones under visiblelightphotoredoxcatalyzed conditions were trapped by chalcones. The subsequent intramolecular cyclization of the resulting benzylic radicals led to the synthesis of dihydronaphthalenes, which were conveniently oxidized to the corresponding naphthalenes. The strategy was adopted successfully for synthesizing derivatives of urundeuvine
Visible Light-Mediated Coupling of α-Bromochalcones with Alkenes
作者:Suva Paria、Viktor Kais、Oliver Reiser
DOI:10.1002/adsc.201400638
日期:2014.9.15
Photoredox catalyzed intermolecular couplings of α‐bromochalcones to olefins have been developed. Employing 1 mol% of the iridium complex Ir(ppy)3 as photocatalyst, vinyl radicals are generated from α‐bromochalcones as the key intermediate, which efficiently engage in a formal [4+2] cyclization with various alkenes. The resulting 3,4‐dihydronaphthalenes can be readily transformed to the corresponding
已经开发了光氧化还原催化的α-溴代查耳酮与烯烃的分子间偶联。使用1 mol%的铱络合物Ir(ppy)3作为光催化剂,乙烯基自由基是由α-溴代查耳酮作为关键中间体生成的,可以有效地与各种烯烃进行正式的[4 + 2]环化反应。生成的3,4-二氢萘可以很容易地转化为相应的萘,并进一步环化为5 H-苯并[ c ]芴。另外,如果烯烃在烯丙基位置具有合适的离去基团,则可以得到Heck型偶联产物与空间受阻更强的烯烃或烯丙基化产物。
Chiral N,N′-dioxide-Sc(NTf<sub>2</sub>)<sub>3</sub> complex-catalyzed asymmetric bromoamination of chalones with N-bromosuccinimide as both bromine and amide source
A chiral N,N[prime or minute]-dioxide-Sc(NTf2)3complex catalytic system has been developed to catalyze the asymmetric bromoamination reaction of chalones with N-bromosuccinimide.
Synthesis of Polysubstituted 2-Aminoimidazoles via Alkene-Diamination of Guanidine with Conjugated α-Bromoalkenones
作者:Sankar K. Guchhait、Neha Hura、Archana P. Shah
DOI:10.1021/acs.joc.6b03021
日期:2017.3.3
A step-economical access to polysubstituted aminoimidazoles has been accomplished via alkene vicinal C–N bonds formation of 2-bromo-2-alkenones with guanidine avoiding its NH-protection/derivatization prerequisite for electronic modulation. The approach has excellent substrate scope, is amenable to diverse guanidine-containing substrates, and introduces distinctive substitutions/functionalities into