A Planar-Chiral Phosphino(alkenyl)ferrocene for Suzuki-Miyaura C-C Coupling Reactions
作者:Dieter Schaarschmidt、Martin Grumbt、Alexander Hildebrandt、Heinrich Lang
DOI:10.1002/ejoc.201402861
日期:2014.10
applied in the presence of palladium in Suzuki–Miyauracouplings for the synthesis of sterically congested biaryls. The catalytic activity arises from homogeneous palladium phosphine complexes, of which the potential pre-catalyst [Pd(4)2Cl2] was characterized structurally. The catalytic system is excellently suited for the synthesis of tri-ortho-substituted biaryls under mild conditions (0.1 mol-%, 50–100
Anionic Phospho-Fries Rearrangement at Ferrocene: One-Pot Approach to P,O-Substituted Ferrocenes
作者:Marcus Korb、Dieter Schaarschmidt、Heinrich Lang
DOI:10.1021/om5002827
日期:2014.4.28
For the first time the anionic phospho-Fries rearrangement has been successfully applied in ferrocene chemistry, giving access to 1,2-P,O-substituted ferrocenes. The 1,3 (O → C)-migration occurs at ferrocenyl phosphates, thiophosphates, phosphite–borane adducts, and phosphinates by treatment with a base such as lithium diisopropylamide at low temperature, whereas the highest yields were obtained starting
阴离子磷酸-弗里斯重排首次成功地应用于二茂铁化学中,从而获得了1,2-P,O-取代的二茂铁。1,3(O→C)迁移发生于二茂铁基磷酸酯,硫代磷酸酯,亚磷酸酯-硼烷加合物和次膦酸酯,是通过在低温下用碱(如二异丙基氨基化锂)处理来实现的,而从二乙基二茂铁基磷酸酯开始获得最高的收率。膦酸酯的伯膦和随后施特尔策P的完全还原,C交叉耦合允许Fe的合成(η 5 -C 5 H ^ 3 -2-OME-PPH 2)(η 5 -C 5 H ^ 5)(1) 。资质1在钯催化的Suzuki-Miyaura C,C偶合中作为支撑配体已通过在温和的反应条件下以良好或优异的收率合成空间拥挤的三邻位取代的联芳基来证明。
Fine Tuning of Chiral Bis(N-heterocyclic carbene) Palladium Catalysts for Asymmetric Suzuki–Miyaura Cross-Coupling Reactions: Exploring the Ligand Modification
作者:Dao Zhang、Jueqin Yu
DOI:10.1021/acs.organomet.0c00036
日期:2020.4.27
aryl–aryl cross-couplingreactions of arylboronic acids and aryl halides. The enantioselectivity of the biaryl products was greatly improved within 24 h (up to 74% ee) when complexes 7a–g were used as catalysts. The results show that for these types of bis(NHC) palladium catalysts the structural characters of the chiral scaffolds play a decisive role in the enantioselectivities of cross-coupling reactions
AbstractThe Pd‐catalyzed Suzuki‐Miyaura cross‐couplings (SMRs) are utilized as the most practical method to construct C−C bond, especial for biaryls. However, a major disadvantage of current protocols is the requirement of excess organoboron coupling partner (1.5–3.0 equiv.). Herein, a novel palladacyclic 1,3‐bis(2,6‐diisopropylphenyl)acenaphthoimidazol‐2‐ylidene (AnIPr) precatalyst possessing a chiral oxazoline was designed, which enabled a general protocol towards bulky tri‐ortho‐substituted biaryls, ternaphthalenes and diarylanthracenes via the Pd‐catalyzed SMR employing equimolar organoborons and aryl bromides. A remarkable scope of substrates with various functional groups and heterocycles were well compatible with an adaptability to synthesize useful ligands.
Modular Design of Fluorescent Dibenzo- and Naphtho-Fluoranthenes: Structural Rearrangements and Electronic Properties
作者:Gavin S. Mohammad-Pour、Richard T. Ly、David C. Fairchild、Alex Burnstine-Townley、Demetrius A. Vazquez-Molina、Khang D. Trieu、Andres D. Campiglia、James K. Harper、Fernando J. Uribe-Romo
DOI:10.1021/acs.joc.8b00891
日期:2018.8.3
naphtho-fluoranthene polycyclic aromatic hydrocarbons (PAHs) with MW = 302 (C24H14) was synthesized via a Pd-catalyzed fluoranthene ring-closing reaction. By understanding the various modes by which the palladium migrates during the transformation, structural rearrangements were bypassed, obtaining pure PAHs in high yields. Spectroscopic and electrochemical characterization demonstrated the profound diversity
通过Pd催化的荧蒽闭环反应合成了MW = 302(C 24 H 14)的12种二苯并蒽和萘并荧蒽多环芳烃(PAHs)库。通过了解转变过程中钯迁移的各种模式,可以绕开结构重排,以高收率获得纯净的PAH。光谱和电化学表征证明了异构体之间电子结构的巨大差异。突出可见光发射方面的显着差异,该PAHs库将使它们的标准化能够用于毒理学评估和作为光电材料的潜在用途。