Heinrich Zollinger Diazo Chemistry II Aliphatic, Inorganic and Organometallic Compounds

Weinheim • New York VCH Basel • Cambridge • Tokyo Contents

Symbols, Quantities and Units XV

Abbreviations and Acronyms XVI

1 Introduction 1 1.1 History of Aliphatic, Inorganic, and Organometallic Diazo Compounds 1 1.2 Nomenclature and General References 5

2 Methods for the Preparation of Alkane, Alkene, and Alkyne Diazo Compounds 11 2.1 Stable Aliphatic Diazonium Ions 11 2.2 Introduction to the Methods for the Synthesis of Aliphatic Diazo Compounds 15 2.3 Preparation of Aliphatic Diazo Compounds by Nitrosation of Aliphatic Amines 20 2.4 Cleavage of N-Alkyl-yV-nitroso Amides 28 2.5 Syntheses Starting with Ketones or Aldehydes 34 2.5.1 Dehydrogenation of Hydrazones 34 2.5.2 Bamford-Stevens Reaction 40 2.5.3 Forster Reaction 46 2.5.4 Miscellaneous Reactions 47 2.6 Diazo Transfer to Active Methylene Compounds 48 2.7 Diazo Transfer to Alkenes 63 2.8 Diazo Transfer to Alkynes 75 2.9 Diazoethene and its Derivatives 81 2.10 Synthesis of Alkenediazonium Salts 83 2.11 Synthesis of Compounds with a Csp-attached Diazonio Group 91 3 Inorganic Diazo Compounds and Metal Complexes with Dinitrogen as Ligand 95 3.1 Addition Products of Dinitrogen to Nonmetallic Inorganic Species 95 3.2 Diazo Derivatives of Polyhedral Boron Hydrides 101 3.3 Addition Products of Dinitrogen to Transition Metal Complexes 107 3.4 Short Review on the Chemistry of Nitrogen Fixation 114

4 Kinetics and Mechanism of Aliphatic Diazotizations 121 4.1 Nitrosation of Alkylamines 121 4.2 Carcinogenicity of iV-Nitrosoamines 127 XII Contents

4.3 Mechanisms of Diazoalkane Syntheses 132 4.4 Acid-Base Equilibria of Aliphatic Diazo Compounds 138

5 The Structure of Aliphatic Diazo Compounds 145 5.1 Aliphatic Diazonium Ions 145 5.2 Diazoalkanes and Related Compounds 146 5.3 Theoretical Investigations on Aliphatic Diazonium Salts, and on Alkane, Alkene, and Alkyne Diazo Compounds 161 5.4 Isomers of Diazomethane 173

6 Reactions of Aliphatic Diazo and Diazonium Compounds not Involving Initial Dediazoniation 191 6.1 Azo Coupling Reactions of Aliphatic Diazonium Ions and Related Processes 191 6.2 Introduction to 1,3-Dipolar Cycloadditions 195 6.3 Mechanism of 1,3-Dipolar Cycloadditions 200 6.4 Regio- and Diastereoselectivity of Dipolar Cycloadditions with Diazoalkanes 212 6.5 Cycloaddition Reactions with Diazoalkanes in Organic Synthesis 228

7 Dediazoniation Reactions Involving Diazonium Ion Intermediates 241 7.1 Introduction to Deamination Mechanisms 241 7.2 Routes to Alkanediazonium Ions 244 7.3 Deamination Mechanisms of Open-Chain Amines: Substitution Products 253 7.4 Eliminations and Rearrangements in Deamination of Open-Chain Amines 271 7.5 Deamination of Alicyclic Amines 278 7.6 A Challenge to Revisit Deamination Mechanisms 290 7.7 Synthetic Applications of Deamination Reactions 295 7.8 Summary and Outlook (by Wolfgang Kirmse) 302

8 Dediazoniation Reactions Involving Carbene and Carbenoid Intermediates 305 8.1 Introduction to General Carbene Chemistry 305 8.2 Formation of Carbenes and Carbenoids by Dediazoniation of Diazoalkanes 314 8.3 Addition of Carbenes to Alkenes 318 8.4 Addition of Carbenes and Carbene Precursors to Aromatic Hydrocarbons and to Fullerene[60] 324 8.5 Insertion, Abstraction, and Rearrangement Reactions of Carbenes 335 8.6 Carbenes from a-Diazocarbonyl Compounds: The Wolff Rearrangement and the Arndt-Eistert Reaction 344 8.7 Transformations Involving Metal Carbenoids 358 8.8 Enantioselective Reactions of Carbenoids 373 Contents XIII

9 Miscellaneous Reactions Involving Diazo and Related Compounds 383 9.1 Electrophilic and Nucleophilic Substitution at the C(a)-Atom of Diazo Compounds 383 9.2 The N(/3)-Electrophilicity of Aliphatic Diazo Compounds 395 9.3 Electron Transfer to and from Diazo Compounds: Ion Radicals 400 9.4 Oxidations and Reductions of Diazo Compounds 408 9.5 Dediazoniations of Alkenediazonium Ions 414

10 Metal Complexes of Diazonium and Diazo Compounds 421 10.1 Structure of Metal Complexes Containing Arenediazonium Ions as Ligands 421 10.2 Synthesis of Aryldiazenido Metal Complexes 430 10.3 Diazoalkanes as Ligands in Transition Metal Complexes 439

11 Epilogue: From Peter Griess' Discovery to Organometallic Diazo Compounds 455

References 459

Index 507