Since the discovery of organic azides by Peter Griess more than 140 years ago, numerous syntheses of these energy-rich molecules have been developed. In more recent times in particular, completely new perspectives have been developed for their use in peptide chemistry, combinatorial chemistry, and heterocyclic synthesis. Organic azides have assumed an important position at the interface between chemistry, biology, medicine, and materials science. In this Review, the fundamental characteristics of azide chemistry and current developments are presented. The focus will be placed on cycloadditions (Huisgen reaction), aza ylide chemistry, and the synthesis of heterocycles. Further reactions such as the aza-Wittig reaction, the Sundberg rearrangement, the Staudinger ligation, the Boyer and Boyer-Aube rearrangements, the Curtius rearrangement, the Schmidt rearrangement, and the Hemetsberger rearrangement bear witness to the versatility of modern azide chemistry.

Organic Azides: An Exploding Diversity of a Unique Class of Compounds

https://chemistry.mdma.ch/hiveboard/rhodium/pdf/archive/merbst/quinoline1999.pdf

Quinoline, quinazoline and acridone alkaloids

A review of ionic liquids: Applications towards catalytic organic transformations

Recent advances in the staudinger reaction

2.5. Ionic Liquids Presented in This Review 2020 3. Cyclocondensation Reactions 2020 4. Synthesis of Three-Membered Heterocycles 2022 4.1. Aziridines 2022 5. Synthesis of Five-Membered Heterocycles 2022 5.1. Pyrroles 2022 5.2. Furans 2022 5.3. Thiophenes 2023 5.4. Pyrazoles 2024 5.5. Imidazoles 2025 5.6. Isoxazoles 2027 5.7. Oxazoles, Oxazolines, and Oxazolidinones 2027 5.8. Thiazoles and Thiazolidinones 2028 6. Synthesis of Six-Membered Heterocycles 2030 6.1. Pyridines 2030 6.2. Quinolines 2031 6.3. Acridines 2033 6.4. Pyrans 2033 6.5. Flavones 2035 6.6. Pyrimidines and Pyrimidinones 2035 6.7. Quinazolines 2037 6.8. -Carbolines 2038 6.9. Dioxanes 2039 6.10. Oxazines 2039 6.11. Benzothiazines 2040 6.12. Triazines 2040 7. Synthesis of Seven-Membered Heterocycles: Diazepines 2041

Ionic liquids in heterocyclic synthesis.

Synthesis of novel carbo- and heteropolycycles. 12. A new versatile synthesis of oxazoles by intramolecular aza-Wittig reaction

A new efficient synthesis of imidazolinones and quinazolinone by intramolecular aza-Wittig reaction

The regioselectivity of N- and C-3(β)-alkylations of indolylmetal salts was studied under various conditions. The effect of counter metal ion is crucial in determining the regioselectivity. In tetrahydrofuran, exclusive N-alkylation occurred with the potassium salt, but the extent of C-3-alkylation increased with the sodium and lithium salts and became predominant with the magnesium bromide salt. However, N-alkylation was favoured generally in more polar solvents and for alkyl toluene-P-sulphonates it was favoured even with magnesium bromide salts. The reactivity and regioselectivity of the alkylations were correlated with the calculated electron density of the indolyl anion and with 13C n.m.r. chemical shifts of the metal salts.

Regioselectivity control in alkylation reactions of indolyl ambident anion

A convenient short-step synthesis of rutecarpine and tryptanthrin as quinazoline alkaloids containing indole skeleton via intramolecular aza-Wittig reaction was described

Short-step synthesis of rutecarpine and tryptanthrin via intramolecular aza-Wittig reaction

A novel route to benzoannelated large-membered cyclic 1,5-diamines from lactams is described. Thus, n-membered lactams 1 were N-acylated by o-azidobenzoyl chloride 5 to afford the corresponding imides 4. These were treated with tributylphosphine and underwent an intramolecular aza-Wittig reaction to give n-membered ring-fused quinazolinones 2 in 84-96% yield. By reductive cleavage of 2 with BH 3 •THF, (n+4)-membered cyclic diamines 3 were obtained in 52-95% yield

Hisato Takeuchi

Papers

Synthesis of novel carbo- and heteropolycycles. 12. A new versatile synthesis of oxazoles by intramolecular aza-Wittig reaction

A new efficient synthesis of imidazolinones and quinazolinone by intramolecular aza-Wittig reaction

Regioselectivity control in alkylation reactions of indolyl ambident anion

Short-step synthesis of rutecarpine and tryptanthrin via intramolecular aza-Wittig reaction

Novel ring enlargement of lactams via quinazolinone annelation. A facile route to benzoannelated large-membered cyclic 1,5-diamines