Imidazolylsulfonates: Electrophilic Partners in Cross-Coupling Reactions
作者:Jennifer Albaneze-Walker、Ravinder Raju、Jennifer A. Vance、Andrew J. Goodman、Michael R. Reeder、Jing Liao、Mathew T. Maust、Patrick A. Irish、Peter Espino、David R. Andrews
DOI:10.1021/ol802381k
日期:2009.4.2
Arylimidazolylsulfonates participate as electrophilic coupling partners in palladium-mediated cross-coupling reactions. The arylimidazolylsulfonates display good stability while maintaining good reactivity in a variety of palladium-catalyzed coupling reactions. Imidazolylsulfonates are a practical and economic alternative to triflates.
Nickel-Catalyzed C−O Activation of Phenol Derivatives with Potassium Heteroaryltrifluoroborates
作者:Gary A. Molander、Floriane Beaumard
DOI:10.1021/ol101592r
日期:2010.9.17
A general method based on nickel-catalyzed C-O activation of various phenol derivatives with potassium (hetero)aryltrifluoroborates has been developed. A large number of heterobiaryls can be easily obtained with yields up to 99% using methanesulfonate cross-coupling partners.
Suzuki−Miyaura Cross-Coupling of Aryl Carbamates and Sulfamates: Experimental and Computational Studies
作者:Kyle W. Quasdorf、Aurora Antoft-Finch、Peng Liu、Amanda L. Silberstein、Anna Komaromi、Tom Blackburn、Stephen D. Ramgren、K. N. Houk、Victor Snieckus、Neil K. Garg
DOI:10.1021/ja200398c
日期:2011.4.27
The first Suzuki-Miyaura cross-coupling reactions of the synthetically versatile aryl O-carbamate and O-sulfamate groups are described. The transformations utilize the inexpensive, bench-stable catalyst NiCl2(PCy3)(2) to furnish biaryls in good to excellent yields. A broad scope for this methodology has been demonstrated. Substrates with electron-donating and electron-withdrawing groups are tolerated, in addition to those that possess ortho substituents. Furthermore, heteroaryl substrates may be employed as coupling partners. A computational study providing the full catalytic cycles for these cross-coupling reactions is described. The oxidative addition with carbamates or sulfamates occurs via a five-centered transition state, resulting in the exclusive cleavage of the aryl C-O bond. Water is found to stabilize the Ni-carbamate catalyst resting state, which thus provides rationalization of the relative decreased rate of coupling of carbamates. Several synthetic applications are presented to showcase the utility of the methodology in the synthesis of polysubstituted aromatic compounds of natural product and bioactive molecule interest.
Synthesis of 3-Substituted Furans by Hydroformylation
作者:Perli Nanayakkara、Howard Alper
DOI:10.1002/adsc.200505238
日期:2006.3
for the synthesis of 3-substitutedfurans by the hydroformylation of substituted propargylic alcohols is described using rhodium acetate and triphenylphosphine in dichloromethane. The hydroformylation reaction proceeds in a regioselective manner under mild reaction conditions. This novel methodology is versatile and can be applied to the synthesis of a variety of 3-aryl-substituted furans.
A one-pot telescopic synthesis of benzo[<i>b</i>]carbazoles and exploration of their liquid crystalline properties
作者:Nirmal Malik、Ritobrata De、Santanu Kumar Pal、S. S. V. Ramasastry
DOI:10.1039/d4cc00721b
日期:2024.4.30
describe a diversity-oriented one-pot telescopic synthesis of various benzo[b]carbazoles with the naphthannulation of indoles as the key step, enabled by an intramolecular furan–olefin Diels–Alder reaction. This strategy is general and efficient across a wide range of substrates. We applied this method to synthesize and characterize the first benzo[b]carbazole-based liquid crystalline materials, where
我们描述了各种苯并[ b ]咔唑的多样性导向的一锅式伸缩合成,以吲哚的环烷化作为关键步骤,通过分子内呋喃-烯烃Diels-Alder反应实现。该策略在多种基材上都是通用且有效的。我们应用这种方法合成并表征了第一个苯并[ b ]咔唑基液晶材料,其中独特的分子设计导致在室温下形成罕见的向列相。