作者:Qiang-Qiang Li、Zaher Shah、Jian-Ping Qu、Yan-Biao Kang
DOI:10.1021/acs.joc.7b02720
日期:2018.1.5
A base-promoted transition metal-free approach to substituted alkenes using alcohols under aerobic conditions using air as the inexpensive and clean oxidant is described. Aldehydes are relatively difficult to handle compared to corresponding alcohols due to their volatility and penchant to polymerize and autoxidize. Wittig ylides are easily oxidized to aldehydes and consequently form homo-olefination
1<i>H-</i>Phosphindoles as Structural Units in the Synthesis of Chiral Helicenes
作者:Keihann Yavari、Souad Moussa、Béchir Ben Hassine、Pascal Retailleau、Arnaud Voituriez、Angela Marinetti
DOI:10.1002/anie.201202024
日期:2012.7.2
Building helicenes: A photochemical cyclization approach affords helicenes in which the fused ring sequence ends with a phosphole unit (see scheme). The stereogenic phosphorus centers of the substrates control the screw sense of helical chirality. The terminal phosphole units undergo photochemical [2+2] annulations to give dimeric helical structures.
Amino Oxazolines as Easily Accessible Water Stable Ligands for Palladium Catalysed Aqueous Heck Reaction
作者:Akeel S. Saiyed、Reshma S. Joshi、Ashutosh V. Bedekar
DOI:10.3184/174751911x13100589976564
日期:2011.7
A series of amino oxazolinyl ligands were screened for palladium catalysed Heck reaction. These ligands work well as phosphine free system in aqueous, micellar medium, can be effectively recovered and reused for subsequent cycles.
Synthesis of Derivatives of Phenanthrene and Helicene by Improved Procedures of Photocyclization of Stilbenes
作者:Harish R. Talele、Monik J. Gohil、Ashutosh V. Bedekar
DOI:10.1246/bcsj.82.1182
日期:2009.9.15
An improved method has been developed for photocyclization of stilbene to construct phenanthrenes and benzo[c]phenanthrenes. This reaction is promoted by iodine while tetrahydrofuran is used as an ...
Enantioenriched Ruthenium-Tris-Bipyridine Complexes Bearing One Helical Bipyridine Ligand: Access to Fused Multihelicenic Systems and Chiroptical Redox Switches
2-pyridyl groups are described. The preparation was performed via an adapted Mallory reaction using aromatic imines as precursors. The obtained novel class of helical 2,2′-bipyridine ligands was then coordinated to Ru(bipy)22+ units, thus affording the first diastereomerically and enantiomericallypure [RuL(bipy)2]2+ (11a,c, L = 6a,c) or [Ru2L′(bipy)4]4+ (12, L′ = 10b) complexes. The topology and stereochemistry
描述了被一个或两个 2-吡啶基取代的新型氮杂[ n ]螺旋烯(6a - d,10a,b,n = 4-7)的合成和光物理和手性光学特性。该制备是通过使用芳族亚胺作为前体的经过调整的 Mallory 反应进行的。然后将获得的新型螺旋 2,2'-联吡啶配体与 Ru(bipy) 2 2+单元配位,从而提供第一个非对映异构和对映异构纯 [RuL(bipy) 2 ] 2+ ( 11a , c , L = 6a , c ) 或 [Ru 2L'(bipy) 4 ] 4+ ( 12 , L' = 10b ) 复合物。详细研究了这些新型金属螺旋结构的拓扑结构和立体化学,特别是使用 X 射线晶体学。有趣的是,与钌 (II) 的配位使得能够在同一支架内制备包含氮杂-和钌-螺旋烯的融合多螺旋系统。详细检查了这些复合物的光物理、手性和氧化还原特性,并证明了有效的氧化还原触发的手性转换活性。