The isoxazolidine ring represents one of the privileged structures in medicinal chemistry, and there have been an increasing number of studies on isoxazolidine and isoxazolidine-containing compounds. ...Optimization of the 1,3-dipolar cycloaddition (1,3-DC), original methods including electrophilic or palladium-mediated cyclization of unsaturated hydroxylamine, has been developed to obtain isoxazolidines. Novel reactions involving the isoxazolidine ring have been highlighted to accomplish total synthesis or to obtain bioactive compounds, one of the most significant examples being probably the thermic ring contraction applied to the total synthesis of (±)-Gelsemoxonine. The unique isoxazolidine scaffold also exhibits an impressive potential as a mimic of nucleosides, carbohydrates, PNA, amino acids, and steroid analogs. This review aims to be a comprehensive and general summary of the different isoxazolidine syntheses, their use as starting building blocks for the preparation of natural compounds, and their main biological activities.
Covering: January 2013 to September 2018Sulfur-containing natural products are a large class of significant functional molecules. Many of these compounds exhibit potent biological activities and ...pharmacological properties; in fact, some of them have been developed into important drugs. The total synthesis of sulfur-containing natural products is a subject that has long attracted significant attention from synthetic organic chemists; to achieve this goal, various methods have been developed over the past years. This review surveys total syntheses of sulfur-containing natural products that introduce sulfur atoms using different sulfurization agents to construct related sulfur-containing moieties.
The chemical properties and applications of tert-butanesulinamide and other sulfinamides are examined. The addition of metalloenamies to azocarboxylates is also studied.
The development and application of continuous flow chemistry methods for synthesis is a rapidly growing area of research. In particular, natural products provide demanding challenges to this ...developing technology. This review highlights successes in the area with an emphasis on new opportunities and technological advances.
The development and application of continuous flow chemistry methods for synthesis have been ongoing in research laboratories for more than a decade, during which time a number of natural product syntheses have been investigated and reported using such tools.
A study investigated the occurrence, biogenesis and synthesis of biologically active carbazole alkaloids, which can be constructed by cycling biphenyls with an orthonitrogen substitute or ...diarylamines. Fischer-Borche synthesis is one avenue by which carbazoles can be prepared.
This advanced undergraduate/graduate textbook teaches readers to design kinetic experiments involving heterogeneous catalysts, to satisfactorily characterize these catalysts, to acquire valid rate ...data, to determine the presence or absence of heat and mass transfer limitations in these data, to select and simplify reaction models, to derive rate expressions based on these models, and to assess the consistency of these rate equations. A special emphasis is placed on assessing mass transfer effects, particularly in liquid-phase reactions. Sufficient background information and discussion of the assumptions related to the derivation of adsorption isotherms and reaction models has been provided to allow the reader to understand the limitations of these models and to feel comfortable in their application. Both ideal and nonideal surfaces are considered, and enzyme catalysis is also discussed. There are numerous worked-out examples, and homework exercises.
The book will be used as a textbook in courses in kinetics and/or catalysis and also as a supplement in advanced undergraduate chemical engineering courses on kinetics and reactor design, as well as a guide for researchers in catalysis in industry. The most probable discipline for its use is chemical engineering, but it can also be used in materials science, fuels science, and chemistry programs.
Many new practitioners in catalysis today are involved singularly or in small groups at small entrepreneurial companies around the world, especially in the United States. This book should be a tremendously useful reference book as these scientists design runs with heterogeneous catalysts, interpret their experimental data, and model the kinetics to describe their results
The ease of synthesis and the exceptional reactivity of alkoxyallenes has led to their use in a large number of highly diverse applications. This Report describes their use in various versions of the ...allene ether Nazarov cyclization. Following a brief introduction to the Nazarov cyclization (Section 1), the oxidative cyclization of vinyl alkoxyallenes is discussed first (Section 2). Nazarov cyclizations of α-alkoxyallenyl vinyl ketones and of α-alkoxyallenyl vinyl tertiary carbinols are covered (Section 3). The discovery and the subsequent rational design of acetals that serve as chiral auxiliaries on the allene in highly enantioselective Nazarov cyclizations is explained (Section 4). Interrupted Nazarov cyclizations of alkoxyallenes that are generated
in situ
from the isomerization of propargyl ethers on solid supports are discussed, including the evolution of a highly diastereoselective, chiral auxiliary controlled version of the reaction. Some applications of the methodology to natural products total synthesis have been included so as to provide the reader with benchmarks with which to judge the utility of the methodology.
The ease of synthesis and the exceptional reactivity of alkoxyallenes has led to their use in a large number of highly diverse applications.
Sulfoximines have gained considerable recognition as an important structural motif in drug discovery of late. In particular, the clinical kinase inhibitors for the treatment of cancer, roniciclib ...(pan‐CDK inhibitor), BAY 1143572 (P‐TEFb inhibitor), and AZD 6738 (ATR inhibitor), have recently drawn considerable attention. Whilst the interest in this underrepresented functional group in drug discovery is clearly on the rise, there remains an incomplete understanding of the medicinal‐chemistry‐relevant properties of sulfoximines. Herein we report the synthesis and in vitro characterization of a variety of sulfoximine analogues of marketed drugs and advanced clinical candidates to gain a better understanding of this neglected functional group and its potential in drug discovery.
The long‐neglected sulfoximine group has recently enjoyed a rapidly increasing interest in the life sciences. The synthetic methodology for sulfoximines has progressed over the last decade; however, the general understanding of this functional group regarding is medicinal‐chemistry‐relevant properties is limited. We report the synthesis and in vitro characterization of six sulfoximine analogues of marketed drugs and clinical candidates.
Quaternary carbon stereocentres-carbon atoms to which four distinct carbon substituents are attached-are common features of molecules found in nature. However, before recent advances in chemical ...catalysis, there were few methods of constructing single stereoisomers of this important structural motif. Here we discuss the many catalytic enantioselective reactions developed during the past decade for the synthesis of single stereoisomers of such organic molecules. This progress now makes it possible to incorporate quaternary stereocentres selectively in many organic molecules that are useful in medicine, agriculture and potentially other areas such as flavouring, fragrances and materials.
PDF
