Tellurium Reagents in Organic Synthesis; Recent Advances. Part 2

Recent synthetic applications of tellurium reagents are reviewed, covering the literature specifically from 1985 to 1990. This review appears in two parts in consecutive issues. Part 1 contains Sections 1-3, and Part 2 contains Sections 4-8. Part 1 1. Introduction 2. Reduction of Organic Substrates with Tellurium Reagents. 2.1. Reduction of Carbonyl Compounds 2.2. Reduction of α,β-Unsaturated Carbonyl Compounds 2.3. Reduction of Double Bonds Conjugated to Aromatic Systems 2.4. Reduction of Imines and Enamines 2.5. Reduction of Thioketones 2.6. Reduction of Nitrogenated Compounds 2.6.1. Nitro Compounds 2.6.2. Nitroso, Hydroxylamino, Azo, and Azoxy Compounds 2.6.3. N-Oxides 2.6.4. Azides 2.7. Dehalogenation by Tellurium Reagents 2.7.1. Debromination of Vicinal Dibromides 2.7.2. Synthesis of Conjugated Dienes by Tellurolate Induced Debrominations 2.7.3. Preparation of o-Quinodimethanes by Dehalogenation of α,α′-Dihalo-o-xylenes using Sodium Aryltellurolates 2.8. Reductive Fission of Carbon-Heteroatom Bonds by Tellurium Reagents 2.8.1. Reductive Dehalogenation of Organic Compounds 2.8.2. Reductive Removal of the Nitro Group from Quaternary Carbons 2.8.3. Reductive Desulfonylation of β-Oxo Sulfones and α-Nitro Sulfones 2.8.4. Partial Desulfurization of Bis-sulfenylated Diarylmethanes and Bis-sulfenylated β-Dicarbonyl Compounds 2.8.5. Dealkylation of Quaternary Ammonium Salts 2.8.6. Dealkylation of Carboxylic Acid Esters 2.8.7. Deacylation of Aryl Carboxylates and Carbonates 2.8.8. Deallylation of Allyl Aryl Ethers 2.8.9. Decarboxylation of 2,2,2-Trichloro-1,1-dimethylethyl and Trichlorethyl Carbamates 2.8.10. Monodeallylation of Diallylquinoline-2,4(1H,3H)-diones 2.9. Reduction of Epoxides 2.9.1 Reductive Opening of Epoxides with Sodium Hydrogen Telluride or Sodium Telluride 2.9.2. Diphenyl Ditelluride Mediated Electroreductive Cleavage of α,β-Epoxy Ketones, Esters and Nitriles 2.10. Miscellanea 3. Tellurium Mediated Formation of Anionic Species and Their Reaction with Eletrophiles 3.1. Reformatsky-Type Reaction 3.2. Cyclopropanation of α,β-Unsaturated Carbonyl Compounds and Alkylidenation of Aldehydes with Dibromomalonates 3.3. Sulfenylation of α-Halocarbonyl Compounds with Diphenyl Disulfide 3.4. Sulfonylation of Alkyl Halides with Sulfonyl Chlorides 3.5. Reaction of Tosyl Azides with Aldehydes Part 2 4. Oxidation of Organic Substrates by Tellurium Reagents 4.1. Diaryl Telluroxides as Selective Oxidizing Reagents 4.2. Bis(4-methoxyphenyl) Telluroxide as a Mediator in Electrolytic Oxidation of Thioamides 4.3. Selective Oxidations with Arenetellurinic Anhydrides 4.4. Selective Oxidation of Sulfides to Sulfoxides with Hydrogen Peroxide Catalyzed by Tellurium Dioxide 4.5. Oxidation of Dibromostilbenes to Benzils with Tellurium Dioxide 4.6. Regeneration of Ketones from the Corresponding Semicarbazones, Azines and Hydrazines with Tellurium Dioxide 4.7. Reaction of Oxidizing Tellurium Reagents with C,C Double Bonds 4.7.1. Epoxidation of Olefins with Polystyrene-Bound Tellurinic Acids 4.7.2. Diacetoxylation and Dimethoxylation of Olefins 4.7.3. Amidotellurinylation of Olefins; Synthesis of 2-Oxazolidinones and 4,5-Dihydrooxazoles 4.8. Oxidation and Hydration of Acetylenes 5. Cyclofunctionalization of Unsaturated Organic Substrates with Tellurium Reagents 5.1. Tellurolactonization of Unsaturated Carboxylic Acids 5.2. Telluroetherification of Unsaturated Alcohols 6. Detellurative Reactions of Tellurium Containing Compounds 6.1. Detellurative Carbonylation of Organo Tellurides; Preparation of Carboxylic Acids 6.2. Palladium Promoted Detellurative Coupling of Organo Tellurides 6.3. Nickel(II) Catalyzed Detellurative Cross-Coupling of Tellurophene with Grignard Reagents leading to Conjugted Dienes 7. Lithium/Tellurium Exchange; Preparation of Organolithium Reagents and Their Capture with Electrophiles 7.1. Generation of Allyl-, Benzyl-, Aryl-, Vinyl-, and Ethynyl-lithium 7.2. Generation of Acyl- and Aroyllithiums 7.3. Generation of Heterosubstituted Methyllithiums 7.4. Generation of Vinylcuprates by Copper/Tellurium Exchange 8. Miscellanea 8.1. Olefination Reactions Employing Tellurium Ylides 8.2. α-Hydroxyalkylation of α,β-Unsaturated Carbonyl Compounds 8.3. Synthesis of α-Arylpropanoic Acids by Oxidative Rearrangement of Aryl α-Telluroethyl Ketones 8.4. The Oxidation of Allylic Phenyl Tellurides 8.5. Conversion of Acyl Chlorides to Ketones via Telluroesters 8.6. Conversion of Allylsilanes into Allylamines via Phenyltellurinylation 8.7. Tellurium Tetrachloride as a Halogenating Agent 8.8. Tellurium Tetrachloride as a Lewis Acid 8.9 Tellurium Tetrachloride as a Catalyst for Cationic Oligo- and Polymerization Reactions 8.10. Tellurium Tetrachloride Promoted Rearrangement of Cycloheptatrienes to Benzylic Alcohols 8.11. Alkoxytellurium(VI) Fluorides as Alkylating Agents 8.12. Tellurium Tetrachloride Mediated Synthesis of 4, 5-Dihydroisoxazoles 8.13. Conversion of α-Dichlorotelluro Ketones to α-Halo Ketones 8.14. 1,1,2-Trihaloalkenes and Dimeric Acetylenes from Acetylenic Tellurium Compounds