Synthesis of spiro-4<i>H</i>-pyrazole-oxindoles and fused 1<i>H</i>-pyrazoles <i>via</i> divergent, thermally induced tandem cyclization/migration of alkyne-tethered diazo compounds
A thermally induced, substrate-dependent reaction of alkynyl diazocompounds has been developed. This transformation produces spiro-4H-pyrazole-oxindoles and fused 1H-pyrazoles in good to high yields from the corresponding alpha-cyano and alpha-sulfonyl diazocompounds. The salient features of this reaction include excellent chemoselectivity and atom-economy, mild reaction conditions, simple purification
The reaction of 2-alkynyl anilines with catalytic amounts of B(C6F5)3 (5 mol%) resulted in the formation of 2-substituted indoles according to an intramolecular hydroamination in good to excellent yields. Reaction intermediates as well as products were characterized by NMR spectroscopy and by X-ray crystallography. The domino hydroamination/hydrogenation sequence allowed the efficient synthesis of
2-炔基苯胺与催化量的B(C 6 F 5)3(5mol%)的反应根据分子内加氢胺化以良好或优异的产率形成了2-取代的吲哚。反应中间体和产物通过NMR光谱和X射线晶体学表征。多米诺加氢胺化/加氢序列允许以高收率有效地合成四氢喹啉8。
Catalytic Arylation of a CH Bond in Pyridine and Related Six-Membered N-Heteroarenes Using Organozinc Reagents
作者:Isao Hyodo、Mamoru Tobisu、Naoto Chatani
DOI:10.1002/asia.201100971
日期:2012.6
Despite significant advances in the catalytic direct arylation of heteroarenes, the application of this reaction to pyridines has been met with limited success. An oxidative nucleophilic arylation strategy has been developed to overcome this problem. Pyridine, pyrazine, quinolone, and related electron‐deficient N‐heteroarenes can be arylated at the most electrophilic site using the developed nickel‐catalyzed
Transition-Metal Controlled Diastereodivergent Radical Cyclization/Azidation Cascade of 1,7-Enynes
作者:Yingying Zhao、Yancheng Hu、Haolong Wang、Xincheng Li、Boshun Wan
DOI:10.1021/acs.joc.6b00655
日期:2016.5.20
M–N3 complex to alkyl radicals. Following this concept, the diastereoselectivity has been switched by modulating the transition metals and the ligands. The Mn(III)-mediated radical cyclization/azidation cascade of 1,7-enynes afforded trans-fused pyrrolo[3,4-c]quinolinones, whereas the Cu(II)/bipyridine system gave cis-products.
已经开发了一种实现en烯非对映异构叠氮化的策略,它采用了从M–N 3络合物到烷基自由基的叠氮化物转移。遵循这个概念,通过调节过渡金属和配体来改变非对映选择性。Mn(III)介导的1,7-烯炔的自由基环化/叠氮化级联反应提供了反式稠合的吡咯并[3,4- c ]喹啉酮,而Cu(II)/联吡啶系统则提供了顺式产物。
Palladium-Catalyzed Carbonylative Annulation Reaction of 2-(1-Alkynyl)benzenamines: Selective Synthesis of 3-(Halomethylene)indolin-2-ones
A novel and selective palladium-catalyzed carbonylative annulation process for the synthesis of 3-(halomethylene)indolin-2-ones was demonstrated. In the presence of PdX2 and CuX2, 3-(halomethylene)indolin-2-ones were selectively obtained from the carbonylative annulations of 2-(1-alkynyl)benzenamines with CO in moderate to good yields.