Modular Synthesis of (Borylmethyl)silanes through Orthogonal Functionalization of a Carbon Atom.

(Borylmethyl)trimethylsilanes are important building blocks in organic synthesis displaying a unique reactivity. Yet, the synthesis of more advanced derivatives is limited by the advanced silicon intermediates required for their preparation. Herein, a one-pot synthesis of (borylmethyl)silanes is developed, sourced on available alkyl-, aryl-, alkoxy-, aryloxy-, and silyl-hydrosilane materials. The privileged reactivity of N-hydroxyphthalimidyl diazoacetate (NHPI-DA) in Si-H insertion and α-silyl redox-active esters in different decarboxylative borylation reactions are scrutinized.

Nickel-Catalyzed Electroreductive Coupling of Alkylpyridinium Salts and Aryl Halides.

An electrochemical, nickel-catalyzed reductive coupling of alkylpyridinium salts and aryl halides is reported. High-throughput experimentation (HTE) was employed for rapid reaction optimization and evaluation of a broad scope of pharmaceutically relevant structurally diverse aryl halides, including complex drug-like substrates. In addition, the transformation is compatible with both primary and secondary alkylpyridinium salts with distinct conditions. Mechanistic insights were critical to enhance the efficiency of coupling using secondary alkylpyridinium salts. Systematic comparisons of the electrochemical and non-electrochemical methods revealed the complementary scope and efficiency of the two approaches.

N-Hydroxyphthalimidyl diazoacetate (NHPI-DA): a modular methylene linchpin for the C-H alkylation of indoles.

Despite the extensive studies on the reactions between conventional diazocompounds and indoles, these are still limited by the independent synthesis of the carbene precursors, the specific catalysts, and the required multi-step manipulation of the products. In this work, we explore redox-active carbenes in the expedited and divergent synthesis of functionalized indoles. NHPI-DA displays unusual efficiency and selectivity to yield insertion products that can be swiftly elaborated into boron and carbon substituents that are particularly problematic in carbene-mediated reactions.

Decarboxylative Alkyl Coupling Promoted by NADH and Blue Light.

Photoexcited dihydronicotinamides like NADH and analogues have been found to generate alkyl radicals upon reductive decarboxylation of redox-active esters without auxiliary photocatalysts. This principle allowed aliphatic photocoupling between redox-active carboxylate derivatives and electron-poor olefins, displaying surprising water and air-tolerance and unusually high coupling rates in dilute conditions. The orthogonality of the reaction in the presence of other carboxylic acids and its utility in the functionalization of DNA is presented, notably using visible light in combination with NADH, the ubiquitous reductant of life.

Viper bite and its complications at a tertiary care centre in southern part of West Bengal: A prospective, clinical, socioeconomic and epidemiological study.

Background: Viper snake bite is a threat to the Indian health system with 83 000 deaths annually. There is a paucity of literature regarding independent risk factors for renal damage due to viper bite. We present the scenario in a rural part of West Bengal and highlight some vital factors to prevent the complications. Methods: We screened all patients with snake bite from January 2012 to December 2015 in Midnapore Medical College and chose definite viper bites according to our inclusion criteria, treated them as per the Indian government protocol, followed them for any acute kidney injury, managed them with haemodialysis (HD) if needed and compared some socioeconomic and clinical factors between HD and non-HD groups to predict the outcome. Results: A total of 1220 snake bites were screened, 660 were viper bites, and 1 80 needed HD at least once. The HD group mostly consists of tribal population (75% v. 45% in non-HD group) who used unscientific first-aid measures. Bite timing was characteristically between 4 a.m. and 8 a.m., especially during defecation in fields, without any considerable seasonal variation. The average bite-to-needle time was 24.6 hours in the HD group and 5.1 hours in the non-HD group, with the average economic burden of ₹3345 in the HD group and ₹730 in the non-HD group. Conclusions: Along with formal education, there is a need to create awareness among the relatively poor tribal population about snake bite to reduce the bite-to-needle time.

Diverse meta-C-H Functionalization of Arenes across Different Linker Lengths.

Arenes containing conformationally flexible long alkyl chains have been successfully functionalized at the meta-position. Good to excellent meta selectivity is achieved for systems with up to 20 atoms between the target C-H bond and the coordinating heteroatom of the directing group. The palladium-catalyzed functionalization reactions include alkylation, cyanation, olefination, and acetoxylation. The meta selectivity is exclusively governed by the design of flexible pyrimidine-based scaffolds.

Remote meta-C-H Cyanation of Arenes Enabled by a Pyrimidine-Based Auxiliary.

An easily removable pyrimidine-based auxiliary has been employed for the remote meta-C-H cyanation of arenes. The scope of this Pd-catalyzed cyanation reaction using copper(I) cyanide as the cyanating agent was demonstrated with benzylsilanes, benzylsulfonates, benzylphophonates, phenethylsulfonates, and phenethyl ether derivatives. The method was utilized for the synthesis of pharmaceutically valuable precursors.

Rhodium-Catalyzed meta-C-H Functionalization of Arenes.

Rhodium-catalyzed ortho-C-H functionalization is well known in the literature. Described herein is the Xphos-supported rhodium catalysis of meta-C-H olefination of benzylsulfonic acid and phenyl acetic acid frameworks with the assistance of a para-methoxy-substituted cyano phenol as the directing group. Complete mono-selectivity is observed for both scaffolds. A wide range of olefins and functional groups attached to arene are tolerated in this protocol.