铜催化羧酸与芳氨基甲酰氯的脱羧交叉偶联

报道了在不加碱的条件下,无配体铜盐能有效催化羧酸和氨基甲酰氯脱羧交叉偶联反应,以CuCl₂为催化剂、苯为溶剂,于120℃条件下反应48h即可实现脱羧交叉偶联过程.在此标准条件下,该催化体系对官能团普适性较好,以较高收率获得了各种酰胺,产物经¹H NMR、¹³CNMR和HRMS表征.     

Photoinduced Metal-Free Decarboxylative Transformations: Rapid Access to Amines,Alkyl Halides,and Olefins

Herein, we report an efficient photocatalytic strategy for the decarboxylative transformations of redox-active esters to construct C=C, C(sp³)−N, and C(sp³)−X bonds in a single-step. This operationally simple method provides a straightforward access to a variety of protected alkyl amines, alkyl halides and olefins under mild conditions in the absence of metals and photocatalysts. The method can successfully be applied to primary, secondary, and tertiary aliphatic carboxylic acid derivatives. Mechanistic studies indicate that the charge transfer complex (CTC) was formed by ⁿBu₄NI with redox-active esters, in which the ⁿBu₄NI acted as both an iodine source and an efficient electron donor.     

Direct Aroylation of Olefins through a Cobalt/Photoredox-Catalyzed Decarboxylative and Dehydrogenative Coupling with α-Oxo Acids

A photoredox/cobalt dual catalytic procedure has been developed that allows benzoylation of olefins. Here the photoredox catalyst effects the decarboxylation of α-ketoacids to form benzoyl radicals. After addition of this radical to styrenes, the cobalt catalyst abstracts a H-atom. Hydrogen evolution from the putative cobalt hydride intermediate allows a Heck-like aroylation without the need for a stoichiometric oxidant. Mechanistic studies reveal that electronically different styrenes lead to a curved Hammett plot, thus suggesting a change in product-determining step in the catalytic mechanism.     

Formation of C(sp3)–C(sp3) Bonds through Nickel‐Catalyzed Decarboxylative Olefin Hydroalkylation Reactions

Olefins and carboxylic acids are among the most important feedstock compounds. They are commonly found in natural products and drug molecules. We report a new reaction of nickel‐catalyzed decarboxylative olefin hydroalkylation, which provides a novel practical strategy for the construction of C(sp³)?C(sp³) bonds. This reaction can tolerate a variety of synthetically relevant functional groups and shows good chemo‐ and regioselectivity. It enables cross‐coupling of complex organic molecules containing olefin groups and carboxylic acid groups in a convergent fashion.     

Decarboxylative Conjunctive Cross‐coupling of Vinyl Boronic Esters using Metallaphotoredox Catalysis

The synthesis of complex alkyl boronic esters through conjunctive cross‐coupling of vinyl boronic esters with carboxylic acids and aryl iodides is described. The reaction proceeds under mild metallaphotoredox conditions and involves an unprecedented decarboxylative radical addition/cross‐coupling cascade of vinyl boronic esters. Excellent functional‐group tolerance is displayed, and application of a range of carboxylic acids, including secondary α‐amino acids, and aryl iodides provides efficient access to highly functionalized alkyl boronic esters. The decarboxylative conjunctive cross‐coupling was also applied to the synthesis of sedum alkaloids.     

氢氟酸盐和三价碘实现的β,γ-不饱和羧酸脱羧氟化反应

介绍了一种基于氧化脱羧过程的合成含氟烯丙基化合物的新方法.利用三乙胺三氢氟酸盐为氟化试剂,在碘苯二乙酸为氧化剂的条件下,对β,γ-不饱和羧酸进行脱羧氟化,反应收率53%～76%.并且开发了一系列含氟烯丙基化合物的应用方法,包括环加成、氧化、还原以及通过活化烯烃实现的氟原子的取代反应（构建C―O,C―S,C―Se,C―N键）.     

Asymmetric Decarboxylative 1,4‐Addition of Malonic Acid Half Thioesters to Vinyl Sulfones: Highly Enantioselective Synthesis of 3‐Monofluoromethyl‐3‐Arylpropanoic Esters

An asymmetric decarboxylative 1,4‐addition of malonic acid half thioesters (MAHTs) to 2‐aryl‐substituted vinyl sulfones has been developed, yielding adducts with excellent enantioselectivity (up to 97 % ee). In view of tuning pK_a values, a quinine‐based benzyl‐substituted thiourea was designed and demonstrated as the most efficient catalyst. The enantioselective synthesis of 3‐monofluorinated analogues of 3‐methyl indanone and (+)‐turmerone has been accomplished from decarboxylative 1,4‐addition adducts with satisfactory results.