Silver Catalysis in Organic Synthesis

Chao-Jun Li, Xihe Bi, Chao-Jun Li, Xihe Bi

• Publisher: Wiley-VCH
• Year: 2018
• Print ISBN: 9783527342815
• eBook ISBN: 9783527807680
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Organic Chemistry

Covers all the aspects of the recent achievements in silver catalyzed reactions

Silver catalysis has emerged as a powerful tool in the field of organic synthesis. This comprehensive book systematically explores the unique performance of silver catalysis, introducing all the recent progress of silver catalysis in organic synthesis. It clearly emphasizes the unique features of silver catalysis and provides the reaction mechanism involved. This two-volume book also provides vivid schematics and tables throughout to enhance the accessibility to the relevant theory and mechanisms.

Silver Catalysis in Organic Synthesis begins with an introduction to Silver Chemistry before moving on to chapters covering: Silver-Catalyzed Cycloaddition Reactions;
Silver-Catalyzed Cyclizations; Silver-Mediated Radical Reactions; Silver-Mediated Fluorination, Perfluoroalkylation and Trifluoromethylthiolation Reactions; Coupling Reactions and C-H Functionalization; Silver-Catalyzed CO2 Incorporation; Silver-Catalyzed Carbene, Nitrene, and Silylene Transfer Reactions; Asymmetric Silver-Catalyzed Reactions; Silver-Catalyzed Reduction and Oxidation of Aldehydes and Their Derivatives; Silver Complexes in Organic Transformations; and Silver Nanoparticles in Organic Transformations.

-Covers recently developed organic reactions catalyzed by silver, along with their reaction mechanism
-Introduces many new reactions and mechanisms related to silver catalysis
-Offers professionals and newcomers in the related fields a survey of new advances in silver catalysis in organic synthesis

Silver Catalysis in Organic Synthesis will appeal to a wide readership including chemists, biochemists, pharmaceutical scientists, biomedical researchers, agriculture scientists, and graduate students in the related fields.

1
Introduction to Silver Chemistry

Paramasivam Sivaguru and Xihe Bi

Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, China

1.1 History and Features of Silver

Silver is a malleable, ductile, and precious metal that has been known since ancient times (its first debut around 5000 BCE) and is located in group 11 (Ib) and period 5 of the periodic table, between the coinage metal copper (period 4) and gold (period 6). Silver is widely distributed in nature. But its abundance in the earth's crust is very low (0.05 ppm) than other metals [1]. It occurs both naturally in its pure form and in ores, particularly derived from all the sulfur bearing lead, copper, gold, tellurides, and zinc, which is extracted through refining [2]. Silver has the atomic number 47 and atomic weight of 107.880, and its ground state electronic configuration is [Kr] 4d¹⁰5s¹, just like copper and gold. Mostly, silver can exist in a mixture of isotopes, ¹⁰⁷Ag and ¹⁰⁹Ag, approximately occurring in the equal proportions. The most common oxidation states of silver are 0 and +1, although some other oxidation states (+2 and +3) are also known [3]. Among these Ag(II) salts/complexes are less stable than that of Ag(I) and Ag(III) salts/complexes. Silver is noticeably diamagnetic, and its magnetic susceptibility is almost independent of temperature from room temperature to just below the melting point.

The elemental silver has the highest electrical conductivity (1·59 µΩ cm at 20 °C) [4], thermal conductivity (429 W m⁻¹ K⁻¹) [5], and optical reflectivity than any other metal, but it has the lowest electrical contact resistance, and its specific heat capacity is 0.23 J kg⁻¹ K⁻¹ at 25 °C. The melting and boiling point of silver is 961.9 and 2212 °C, respectively [6]. The heat of fusion of silver is 11.28 kJ mol⁻¹, and its hardness is 2.7 on the Mohs scale.

1.1.1 Chemistry of Silver

It has been recognized that the outer orbital 5s¹ electronic configuration of silver allowed to form numerous silver(I) salts/complexes with a wide variety of counterions (halide, sulfide, nitrate, oxide, acetylide compounds, cyano‐derivatives, and olefin complexes). Silver dissolves readily in nitric acid to form silver nitrate (Eq. 1.1), which is a transparent crystalline solid that is readily soluble in water, and is a photosensitive. In addition, it is a precursor for the preparation of various other silver compounds. Silver could also dissolve rapidly with hot concentrated sulfuric acid (Eq. 1.2). However, in the presence of ethanol, silver reacts with nitric acid to give the silver fulminate (AgCNO), which is a powerful touch‐sensitive explosive used in percussion caps [7]. Also, silver nitrate reacts with sodium azide (NaN₃) to form silver azide (AgN₃), which is also used as an explosive [8]. Silver or silver nitrates simply precipitate as silver chloride in the presence of chlorides, which are used in the photographic emulsion:

1.1

1.2

Furthermore, silver nitrate could easily react with copper to produce the silver crystals (Eq. 1.3). The alkaline solution of copper also reduces the silver nitrate into silver in the presence of reducing sugars. Tollens' test/silver mirror test is a qualitative test to distinguish between an aldehyde and ketone. The Tollens' reagent [Ag(NH₃)₂]⁺ is prepared from silver nitrate by two‐step process. In the first step, under basic conditions silver nitrate forms an insoluble silver oxide (Eq. 1.4), and it dissolves readily with the addition of sufficient aqueous ammonia (Eq. 1.5), which oxidizes an aldehyde into corresponding carboxylic acid (Eq. 1.6) [9]:

1.3

1.4

1.5

1.6

Silver is stable in oxygen and water, but it is tarnishing in the presence of ozone or hydrogen sulfide or sulfur in air/water owing to the formation of a black silver sulfide layer. Besides, silver readily forms soluble silver complexes such as Ag(NH₃)₂⁺, Ag(S₂O₃)₂³⁻, and Ag(CN)₂⁻ with ...

Table of contents

• Cover
• Table of Contents
• Preface
• 1 Introduction to Silver Chemistry
• 2 Silver‐catalyzed Cycloaddition Reactions
• 3 Silver‐Catalyzed Cyclizations
• 4 Silver‐Mediated Radical Reactions
• 5 Silver‐Mediated Fluorination, Perfluoroalkylation, and Trifluoromethylthiolation Reactions
• 6 Coupling Reactions and CH Functionalization
• 7 Silver‐Catalyzed CO2 Incorporation
• 8 Silver‐Catalyzed Carbene, Nitrene, and Silylene Transfer Reactions
• 9 Asymmetric Silver‐Catalyzed Reactions
• 10 Silver‐Catalyzed Reduction and Oxidation of Aldehydes and Their Derivatives
• 11 Silver Complexes in Organic Transformations
• 12 Silver Nanoparticles in Organic Transformations
• Index
• End User License Agreement