Dual Transition Metal Electrocatalysis: Direct Decarboxylative Alkenylation of Aliphatic Carboxylic Acids.

Direct decarboxylative alkenylation of widely available aliphatic carboxylic acids with vinyl halides for the synthesis of alkenes with all substitution patterns has been accomplished by means of Ce/Ni dual transition metal electrocatalysis. The reactions employ alkyl acids as the limiting reagents and exhibit a broad scope with respect to both coupling partners. Notably, simple primary alkyl carboxylic acids could be readily engaged as carbon-centered radical precursors in the reaction. This new alkenylation protocol has been successfully demonstrated in direct modification of naturally occurring complex acids and is amenable to the enantioselective decarboxylative alkenylation of arylacetic acid. Mechanistic studies, including a series of controlled experiments and cyclic voltammetry data, allow us to probe the key intermediates and the pathway of the reaction.

Electrophotochemical Metal-Catalyzed Decarboxylative Coupling of Aliphatic Carboxylic Acids.

An electrophotochemical dual metal-catalyzed protocol for decarboxylative arylation of simple aliphatic carboxylic acids with aryl halides is reported. The relative stabilities of catalytically active metal complexes simultaneously generated at anode and cathode are the key design elements for the success of this convergent paired electrolysis. This new electrophotocatalytic method is mild, robust, and most importantly, capable of accommodating simple primary aliphatic acids including acetic acid - ubiquitous and variegated structural motifs yet remain oddly challenging substrates - directly as native functional groups for decarboxylative C(sp2 )-C(sp3 ) bond formation.

Harnessing Radical Chemistry via Electrochemical Transition Metal Catalysis.

The merger of transition metal catalysis and electroorganic synthesis has recently emerged as a versatile platform for the development of highly enabling radical reactions in a sustainable fashion. Electrochemistry provides access to highly reactive radical species under extremely mild reaction conditions from abundant native functionalities. Transition metal catalysts can be used as redox-active electrocatalysts to shuttle electrons, chiral information to organic substrates, and the reactive intermediates in the electrolytic systems. The combination of these strategies in this mechanistic paradigm thus makes the generation and utilization of radical species in a chemoselective manner and allows further application to more synthetically attractive enantioselective radical transformations. This perspective discusses key advances over the past few years in the field of electrochemical transition metal catalysis and demonstrates how the unique features of this strategy permit challenging or previously elusive transformations via radical pathways to be successfully achieved.

Copper-catalyzed chemoselective synthesis of 4-trifluoromethyl pyrazoles.

A series of 4-trifluoromethyl pyrazoles have been prepared via the copper-catalyzed cycloaddition of 2-bromo-3,3,3-trifluoropropene with a variety of N-arylsydnone derivatives under mild conditions. This new protocol under optimized reaction conditions [Cu(OTf)2/phen, DBU, CH3CN, 35 °C] afforded 4-trifluoromethyl pyrazoles in moderate to excellent yields with excellent regioselectivity.

Copper-catalyzed synthesis of 2,2-difluoro-1,3-benzoxathioles(selenoles) and their insecticidal activities: the selenium effect.

An efficient catalytic method for the synthesis of 2,2-difluoro-1,3-benzoxathioles(selenoles) from the reaction of o-bromophenols with trifluoromethanethiolates or selenolates is disclosed. Some of the title compounds exhibited excellent insecticidal activities.

Ubiquitin ligase UBE3C promotes melanoma progression by increasing epithelial-mesenchymal transition in melanoma cells.

Melanoma is the most aggressive type of skin cancer, exhibiting extensive local invasion and early distant metastasis. Aberrant expression of ubiquitin-protein ligase E3C (UBE3C) plays a key role in tumor development and progression. In the present study, we analyzed UBE3C expression in samples of cancerous and normal skin tissue. Levels of UBE3C expression were much higher in primary and metastatic melanoma tissues than in normal skin, cutaneous squamous cell carcinoma or basal cell carcinoma. Melanoma cells overexpressing UBE3C frequently exhibited a mesenchymal phenotype, including reduced expression of the epithelial marker E-cadherin and expression of the mesenchymal marker vimentin. Knockdown of UBE3C expression in melanoma cells significantly suppressed melanoma growth and progression. Furthermore, silencing UBE3C led to increased E-cadherin expression and decreased vimentin and Snail1 expression. Thus UBE3C promotes melanoma progression, possibly by inducing epithelial-mesenchymal transition in melanoma cells. Inhibiting UBE3C activity may suppress melanoma invasion and metastasis and may represent a targeted therapeutic approach.

[Clinical trials of treatment of acute facial paralysis with pain by blood-letting plus acupuncture in patients].

OBJECTIVE: To observe the clinical therapeutic effect of blood-letting plus acupuncture intervention for acute facial paralysis with pain (damp-heat type of liver and gallbladder). METHODS: A total of 120 cases of acute facial paralysis with pain were randomly and equally divided into control group and treatment group. Patients of the control group were treated by simple acupuncture therapy only, and patients of the treatment group treated by acupuncture plus bloodletting at the ipsilateral Yangbai(GB 14) and Quanliao (SI 18), and Dazhui (GV 14) and Yifeng (TE 17), alternatively. Shallow-acupuncture stimulation of ipsilateral Cuanzhu (BL 2), Sizhukong (TE 23), Sibai (ST 2), Dicang (ST 4), Jiache (ST 6), Yingxiang (SP 9), and bilateral Hegu (LI 4), Yanglingquan (GB 34) and Xingjian (LR 2) was administered for 30 min, once daily for one month. The patients' facial pain degree was evaluated by visual analogue scale (VAS), and the pain duration during acute stage was recorded. The facial nerve function and facial nerve function recovery (grade II) time were determined by using Sunnybrook Facial Grading scale and House-Brackmann (HB) grading scale, respectively. RESULTS: In comparison with pre-treatment, the post-aurem pain scores after the first treatment and after the acute stage were significantly decreased, and the facial nerve function scores after the treatment were significantly increased in both control and treatment groups (P < 0.01), and the effects of the treatment group were significantly superior to those of the control group (P < 0.01). The post-aurem pain duration and the time of facial nerve function recovery (HB) of the treatment group were considerably lower than those of the control group (P < 0.01). Of the 58 and 59 facial palsy patients in the control and treatment groups, 16 (27.6%) and 24 (40.7%) were cured, 18 (31.0%) and 23 (39.0%) experienced marked improvement, 15 (25.9%) and 10 (16.9%) were improved, and 9 (15.5%) and 2 (3.4%) were failed, with the effective rate being 85.0% and 96.6%, respectively. CONCLUSION: Bloodletting combined acupuncture is effective in the treatment of acute facial paralysis with pain.