Pd-Catalyzed α-Arylation of α,α-Difluoroketones with Aryl Bromides and Chlorides. A Route to Difluoromethylarenes
作者:Shaozhong Ge、Wojciech Chaładaj、John F. Hartwig
DOI:10.1021/ja501117v
日期:2014.3.19
α-difluoroketones with aryl and heteroaryl bromides and chlorides catalyzed by an air- and moisture-stable palladacyclic complex containing P(t-Bu)Cy2 as ligand. The combination of this Pd-catalyzed arylation and base-induced cleavage of the acyl–aryl C–C bond within the α-aryl-α,α-difluoroketone constitutes a one-pot, two-step procedure to synthesize difluoromethylarenes from aryl halides. A broad range
Pd-Catalyzed α-Arylation of Trimethylsilyl Enolates of α,α-Difluoroacetamides
作者:Shaozhong Ge、Sophie I. Arlow、Michael G. Mormino、John F. Hartwig
DOI:10.1021/ja508590k
日期:2014.10.15
ilyl)acetamides with aryl and heteroaryl bromides catalyzed by an air- and moisture-stable palladacyclic complex containing P(t-Bu)2Cy as ligand. A broad range of electronically varied aryl and heteroaryl bromides underwent this transformation to afford α-aryl-α,α-difluoroacetamides in high yields. Due to the electrophilicity of the fluorinated amide, this palladium-catalyzed cross-coupling reaction
A novel PVP-I catalyzed acetalizations/transacetalizations of carbonyl compounds has been developed processing with a mild and easy handling fashion. Different types of Acyclic and cyclic acetals were prepared from carbonyl compounds or their acetals successfully. Further applications of newly developed catalytic combination were testified. This protocol featured with simplicity of operation, mild
A Facile Synthesis of 1,3,5-Triaryl Benzenes from Acetophenone Diethyl Ketals in the Presence of Acetyl Chloride and SmCl<sub>3</sub>
作者:Ke-Jun Cheng、Zong-Biao Ding、Shi-Hui Wu
DOI:10.1080/00397919708004800
日期:1997.1.1
Abstract Samarium trichloride, SmCl3, has been found to be an efficient catalyst for the synthesis of 1,3,5-triaryl benzenes from acetophenone diethyl ketals in the presence of acetylchloride under solvent of pentane and mild conditions.
Catalytic Asymmetric α-Iminol Rearrangement: New Chiral Platforms
作者:Xin Zhang、Richard J. Staples、Arnold L Rheingold、William D. Wulff
DOI:10.1021/ja5065685
日期:2014.10.8
A series of 19 different asymmetric catalysts were screened in an effort to identify the first chiral catalyst for the rearrangement of α-hydroxy imines to α-amino ketones involving a 1,2-carbon shift. Although aluminate complexes of VAPOL, VANOL, and 7,7′-tBu2VANOL were quite effective catalysts giving up to 88% ee, the ne plus ultra catalyst for this reaction was found to be a zirconium complex of
筛选了一系列 19 种不同的不对称催化剂,以确定第一个手性催化剂,用于将 α-羟基亚胺重排为 α-氨基酮,涉及 1,2-碳位移。尽管 VAPOL、VANOL 和 7,7'-tBu2VANOL 的铝酸盐配合物是非常有效的催化剂,可提供高达 88% 的 ee,但发现用于该反应的 ne plus 超催化剂是 VANOL 的锆配合物,可提供 97 至 >99% ee 对于大多数检查的底物。该催化剂的 X 射线衍射研究表明,锆以具有三个 VANOL 配体和两个质子化 N-甲基咪唑的均配配合物形式存在。