Acid Promoted Tetrafunctionalization of Terminal Alkynes: Geminal Diazidation and Dibromination.

The synthesis of complex alkanes by the tetrafunctionalization of alkynes is limited and challenging. Herein, an unprecedented efficient geminal diazidation and dibromination of terminal alkynes is developed, which provides novel access to structurally diverse organic azides. The approach has exclusive chemo- and regioselectivity and features mild reaction conditions, good tolerance of various functional groups, and more crucially, no metal involved in the reaction, thereby benefiting the late-stage decoration of medicinal molecules.

Palladium-Catalyzed Intermolecular Dehydrogenative C-2 Pentenylation of Indoles with 2-Methyl-2-butene.

Five-carbon (C) units are the fundamental building blocks that constitute a multitude of natural products. Herein we report an unprecedented unusual C functionalization of indole regioselectively at the C-2-position enabled by a (2-pyridyl)sulfonyl-directing palladium-catalyzed dehydrogenative strategy with a bulk chemical 2-methyl-2-butene as a C source. Compared to typical C functionalization using pentenyl alcohols, carbonates, borates, or halides as the C source, the protocol not only has a low cost advantage but also is of atom and step economy.

Synthesis of meta-carbonyl phenols and anilines.

Phenols and anilines are of extreme importance for medicinal chemistry and material science. The development of efficient approaches to prepare both compounds has thus long been a vital research topic. The utility of phenols and anilines directly reflects the identity and pattern of substituents on the benzenoid ring.

Regioselective Dehydrogenative Reverse Prenylation of Indoles with 2-Methyl-2-butene.

Bulk chemical 2-methyl-2-butene, one of the main C5 distillates of the petrochemical industry, has scarcely been utilized directly in synthesizing high-value-added fine chemicals. Herein, we use 2-methyl-2-butene as the starting material to develop a palladium-catalyzed highly site- and regio-selective C-3 dehydrogenation reverse prenylation of indoles. This synthetic method features mild reaction conditions, a broad substrate scope, atom- and step-economies.

Synthesis of 5,6-Dihydrophenanthridines via Palladium-Catalyzed Intramolecular Dehydrogenative Coupling of Two Aryl C-H Bonds.

5,6-Dihydrophenanthridines are common aza heterocycle frameworks of natural products and pharmaceuticals. Herein, we reported the first palladium-catalyzed intramolecular C-H/C-H dehydrogenative coupling reaction of two simple arenes to generate 5,6-dihydrophenanthridines. The approach features a broad substrate scope and good tolerance of functional groups, offering an efficient alternative synthesis route for important 5,6-dihydrophenanthridine compounds.

Delayed diagnosis and management of necrotizing fasciitis of the left lower leg: A case report.

Introduction: Necrotizing fasciitis (NF) is a rare, severe soft tissue infection, characterized by rapid and extensive necrosis of the skin, subcutaneous tissue, and superficial and deep fascia. It is frequently misdiagnosed as other infectious diseases, leading to inappropriate treatment and potentially serious consequences. It may be complicated by septic shock and multiple organ failure with a fatal outcome.

Synthesis of Acyl Hydrazides via a Radical Chemistry of Azocarboxylic -Butyl Esters.

A new chemistry of azo compounds, that is, addition of free radicals generated in situ to access various acyl hydrazides, has been developed. The protocol provides a novel strategy for the synthesis of valuable acyl hydrazides. The transformation features mild reaction conditions, good tolerance of functional groups, and a broad substrate scope.

Se-(Fluoromethyl) Benzenesulfonoselenoates: Shelf-Stable, Easily Available Reagents for Monofluoromethylselenolation.

A new class of electrophilic monofluoromethylselenolation reagents, Se-(fluoromethyl) benzenesulfonoselenoates, has been developed. They can be readily prepared from sodium benzenesulfinates, Se powder and ClCFH in one step under mild reaction conditions. Se-(fluoromethyl) benzenesulfonoselenoates are efficient electrophilic monofluoromethylselenolation reagents for a wide range of nucleophiles including indole, 6-azaindole, pyrrole, thiophene, electron-rich arene, aryl boronic acid and alkyne.

Incidence of extrauterine growth retardation and its risk factors in very preterm infants during hospitalization: a multicenter prospective study.

Objectives: To investigate the incidence of extrauterine growth retardation (EUGR) and its risk factors in very preterm infants (VPIs) during hospitalization in China.

Methods: A prospective multicenter study was performed on the medical data of 2 514 VPIs who were hospitalized in the department of neonatology in 28 hospitals from 7 areas of China between September 2019 and December 2020. According to the presence or absence of EUGR based on the evaluation of body weight at the corrected gestational age of 36 weeks or at discharge, the VPIs were classified to two groups: EUGR group (=1 189) and non-EUGR (=1 325).

Palladium-Catalyzed Three-Component Regioselective Dehydrogenative Coupling of Indoles, 2-Methylbut-2-ene, and Carboxylic Acids.

Five-carbon (C5) structural units are the fundamental building blocks of many natural products. An unprecedented palladium-catalyzed three-component dehydrogenative cascade coupling of indoles, 2-methylbut-2-ene, and carboxylic acids has been developed. The approach enables the straightforward introduction of a C3'-bonded five-carbon structural unit with a tertiary alcohol quaternary carbon center into indoles.

Aerobic Oxidative Dehydrogenation of Ketones to 1,4-Enediones.

An efficient and unprecedented strategy for the synthesis of 1,4-enediones from saturated ketones has been developed via palladium-catalyzed oxidative dehydrogenation. The protocol employs molecular oxygen as the sole oxidant and represents an atom- and step-economic process. The approach showed broad substrate scope, good functional group tolerance, and complete -stereoselectivity.