Hasil untuk "Organic chemistry"

Xiaoyu Yang, Tao Wu, Robert J. Phipps et al.

Despite being largely absent from natural products and biological processes, fluorine plays a conspicuous and increasingly important role within pharmaceuticals and agrochemicals, as well as in materials science.1a−1c Indeed, as many as 35% of agrochemicals and 20% of pharmaceuticals on the market contain fluorine.1d Fluorine is the most electronegative element in the periodic table, and the introduction of one or more fluorine atoms into a molecule can result in greatly perturbed properties. Fluorine substituents can potentially impact a number of variables, such as the acidity or basicity of neighboring groups, dipole moment, and properties such as lipophilicity, metabolic stability, and bioavailability. The multitude of effects that can arise from the introduction of fluorine in small molecules in the context of medicinal chemistry has been extensively discussed elsewhere.2 For these reasons, methods to introduce fluorine into small organic molecules have been actively investigated for many years by specialists in the field of fluorine chemistry. However, particularly in the past decade, a combination of the increasing importance of fluorine-containing molecules and the successful development of bench stable, commercially available fluorine sources has brought the expansion of fluorine chemistry into the mainstream organic synthesis community. This has resulted in an acceleration in the development of new fluorination methods and consequently in methods for the asymmetric introduction of fluorine.3 Catalytic asymmetric fluorination methods have inevitably lagged somewhat behind their nonasymmetric counterparts as understanding of the modes of reactivity of new fluorinating reagents must generally be developed and understood before they can be extended to enantioselective catalysis.3b Indeed, the last special issue of Chemical Reviews dedicated to fluorine chemistry, in 1996, contained no articles addressing asymmetric fluorine chemistry, and the editor of the issue noted that “although fluorine chemistry is much less abstruse now than when I entered the field a generation ago, it remains a specialized topic and most chemists are unfamiliar, or at least uncomfortable, with the synthesis and behavior of organofluorine compounds.”4 The field has undoubtedly undergone great change within the last two decades. As with the incorporation of the fluorine atom, the introduction of the trifluoromethyl (CF3) group into organic molecules can substantially alter their properties. As with fluorine, the prevalence of CF3 groups in pharmaceuticals and agrochemicals coupled with the development of new trifluoromethylating reagents also has led to a recent surge in the development of asymmetric trifluoromethylation and perfluoroalkylation. Although the fluorine and trifluoromethyl moieties are often found on the aromatic rings of many pharmaceutical and agrochemicals rather than in aliphatic regions, this may be a result of the lack of efficient methods for the asymmetric introduction of C–F and C–CF3 bonds into molecules; it could be the case that lack of chemical methods is restricting useful exploration of such molecules. However, there are still encouraging examples of drug candidates containing chiral fluorine and trifluoromethyl-bearing carbons (Figure ​(Figure11). Figure 1 Molecules of medicinal interest bearing C–F and C–CF3 stereocenters.

M. Stępień, Elżbieta Gońka, Marika Żyła et al.

A. Wendlandt, Alison M. Suess, S. Stahl

M. Cokoja, Christian Bruckmeier, B. Rieger et al.

Joseph W. Tucker, C. Stephenson

Chang-Liang Sun, Zhangjie Shi

Lei Shi, W. Xia

D. Stephan

J. Nie, Hong-Chao Guo, D. Cahard et al.

J. Wilkes

W. Herrmann

E. Pelizzetti, N. Serpone

R. Gennis

K. Jaeger, M. Reetz

Daniel Kaiser, Immo Klose, Rik Oost et al.

Organosulfur compounds have long played a vital role in organic chemistry and in the development of novel chemical structures and architectures. Prominent among these organosulfur compounds are those involving a sulfur(IV) center, which have been the subject of countless investigations over more than a hundred years. In addition to a long list of textbook sulfur-based reactions, there has been a sustained interest in the chemistry of organosulfur(IV) compounds in recent years. Of particular interest within organosulfur chemistry is the ease with which the synthetic chemist can effect a wide range of transformations through either bond formation or bond cleavage at sulfur. This review aims to cover the developments of the past decade in the chemistry of organic sulfur(IV) molecules and provide insight into both the wide range of reactions which critically rely on this versatile element and the diverse scaffolds that can thereby be synthesized.

C. N. Sawyer, P. McCarty, G. Parkin

K. V. van Bommel, A. Friggeri, S. Shinkai

Hai Wang, Tianhong Huang, Jiawei Chang

The wave-particle duality of massive macromolecules -- such as the fullerene C$_{60}$ -- is a well-established quantum phenomenon. However, whether the quantum behavior of large organic molecules actively dictates the macroscopic structure and function of synthetic materials remains unknown. In organic semiconductors, crystal polymorphism fundamentally determines optoelectronic performance, yet classical thermodynamic models consistently fail to resolve the microscopic origins of phase selection. This includes the long-standing anomaly of divergent polymorph formation under identical thermodynamic parameters across different reactor scales. Here we show that the polymorphism of copper phthalocyanine (CuPc, 576 Da) -- a planar macromolecule comparable in mass to C$_{60}$ -- is governed by quantum coherence during atmospheric-pressure organic vapor phase deposition (OVPD). We establish the Dissipative structure field-Induced Multipartite Entanglement (DIME) framework, which integrates ambient blackbody radiation, molecular de Broglie wavelengths, and frontier orbital directionality to model field-driven quantum entanglement. We demonstrate that exceptionally weak environmental decoherence at room temperature preserves the coherence of molecular matter waves, enabling the self-assembly of ultralong ($>1$ cm) single-crystalline $η$-CuPc nanowires. By leveraging the DIME framework to manipulate environmental decoherence, we rationally designed an OVPD reactor to synthesize a previously undiscovered polymorph, designated $ω$-CuPc. Our findings reveal that multipartite quantum entanglement acts as the decisive regulator of organic crystal assembly, opening a deterministic, quantum-level pathway for engineering organic semiconductor polymorphism.

Joe Pratt-Johns, Toby St. Clere Smithe, Chris Guiver et al.

We construct a functor that gives a dynamics to an algebraic model of interacting components. The construction generalises a computational model of Fontana and Buss in the field of artificial life known as AlChemy, in which molecules and their chemical interactions are emulated by lambda calculus terms and their application and subsequent reduction. We discuss future directions for the application of category theory to algebraic artificial chemistry as an organisational tool, with a focus on formalising the connection between the algebraic and the dynamical facets of such models.

P. Schmitt‐Kopplin, Z. Gabelica, R. Gougeon et al.