Highly Efficient Pd-Catalyzed Coupling of Arenes with Olefins in the Presence of tert-Butyl Hydroperoxide as Oxidant
摘要:
[GRAPHICS]ArH : benzoid and non-benzoid. R = H, CH3, Ph. R-1 = Ph, Co2Et, COMe, CHO, CO2H, CN.The oxidative coupling of arenes with olefins has been performed efficiently in the presence of catalytic amounts of palladium acetate and benzoquinone (BQ) with tert-butyl hydroperoxide as the oxidant in up to 280 turnover numbers (TON). The catalytic system is especially active for the coupling of heterocycles such as furans and indole with activated olefins, The reaction is highly regio- and stereoselective, giving trans-olefins predominantly.
Organocatalyzed Asymmetric Conjugate Addition of Heteroaryl and Aryl Trifluoroborates: a Synthetic Strategy for Discoipyrrole D
作者:Jiun‐Le Shih、Thien S. Nguyen、Jeremy A. May
DOI:10.1002/anie.201503528
日期:2015.8.17
Bis‐heteroaryl or bis‐aryl stereocenters were formed by an organocatalytic enantioselective conjugateaddition using the respective trifluoroborate salts as nucleophiles. Control studies suggested that fluoride dissociation is necessary in the anhydrous conditions. This strategy is applicable to the synthesis of discoipyrroleD, an inhibitor of BR5 fibroblast migration.
<i>N</i>-Vinylpyridinium and -ammonium Tetrafluoroborate Salts: New Electrophilic Coupling Partners for Pd(0)-Catalyzed Suzuki Cross-Coupling Reactions
作者:Keith R. Buszek、Neil Brown
DOI:10.1021/ol063027h
日期:2007.2.1
N-Vinylpyridinium and -trialkylammonium tetrafluoroborate salts represent a new class of electrophilic coupling partner for Pd(0)-catalyzed Suzuki cross-coupling reactions and give very good to excellent yields of products with a wide range of boronic acids. The salts are easily prepared from activated acetylenes and pyridinium or trialkylammonium tetrafluoroborates to form crystalline, air-stable
enantioselective 1,2-reduction of α,β-unsaturated ketones has been achieved using a chiral pincer Mn catalyst. A series of PNN tridentate ligands containing benzimidazole groups were designed with ferrocene as the backbone, which coordinated with Mn to form the active catalyst. This mild process represents a general method to access chiralallyl alcohols with high catalytic activity (up to 9500 TON) and high enantioselectivity
Palladium-Catalyzed Alkynylation of Enones with Alkynylsilanes via C–C Bond Activation
作者:Yu-Wen Liu、Ling-Jun Li、Hui Xu、Hui-Xiong Dai
DOI:10.1021/acs.joc.2c00498
日期:2022.5.20
We report herein the synthesis of 1,3-enynes via palladium-catalyzed cross-coupling between enone derivatives and alkynylsilanes. The employment of an appropriate pyridine-oxazoline ligand is the key to the C–C cleavage and the high E/Z stereoselectivity. This protocol features broad substrate scope and wide functional-group tolerance, affording the desired products in moderate-to-good yields. Late-stage