A review on DBU-mediated organic transformations

Figures & data

Figure 1. Structure of DBU catalyst.

Scheme 1. Stabilization of protonated DBU.

Scheme 2. Synthesis of DBU.

Scheme 3. Synthesis of amidation of alkyl cyanoacetates.

Scheme 4. Synthesis of 3,4-bis-O-alkyl-1-alky1-5-(2-hydroxyethyl)-5-hydroxy-1,5 -dihydropyrrol-2-ones.

Scheme 5. Synthesis of amidation of α-functional aldehydes.

Scheme 6. Synthesis of 1-alkoxypyrazino [1,2-a] indoles.

Scheme 7. Synthesis of amidation of acyl imidazoles.

Scheme 8. Synthesis of N-protected amino weinreb amides and peptidyl weinreb amides.

Scheme 9. Synthesis of amidation and amination of (Hetero) aryl chlorides.

Scheme 10. Synthesis of alkenes.

Scheme 11. Synthesis of 2-methylbenzofurans.

Scheme 12. Synthesis of 1,3-dimethyl-6-propyl uracil.

Scheme 13. Synthesis of symmetrical diynes.

Scheme 14. Synthesis of symmetrical/unsymmetrical 3,4-diaryl maleimides.

Scheme 15. Synthesis of 5-exophthalides.

Scheme 16. Synthesis of O-alkyl phthalides.

Scheme 17. Synthesis of fused heteroaryl pyrazinones.

Scheme 18. Synthesis of 4,4’-Bi-1H-imidazol-2-ones.

Scheme 19. Synthesis of 2,3-substituted γ-benzopyranones.

Scheme 20. Synthesis of highly substituted 4H-pyrans.

Scheme 21. Synthesis of N-substituted 1,3-dihydrobenzimidazol-2-ones.

Scheme 22. Synthesis of indole derivatives.

Scheme 23. Synthesis of ortho-acylphenols.

Scheme 24. Synthesis of ethyl thioesters.

Scheme 25. Synthesis of N-, O-, and S-benzylation derivatives.

Scheme 26. Synthesis of poly(p-nitrobenzylmethylacrylate) and poly[4-(4-nitrobenzyloxy)styrene].

Scheme 27. Synthesis of per-O-acetylation of cellulose moiety.

Scheme 28. Synthesis of methyl esters.

Scheme 29. Synthesis of diaryl thioethers and S-cycles.

Scheme 30. Synthesis of N-substituted carbamic acid esters.

Scheme 31. Synthesis of bromoaryl compounds.

Scheme 32. Synthesis of di α-halogenation of nitromethyl group attached to an aryl/alkyl compounds.

Scheme 33. Synthesis of bromo allyl alcohol derivatives.

Scheme 34. Synthesis of a herbicide process.

Scheme 35. Synthesis of α-cyano-γ-butyrolactonebispirooxindoles.

Scheme 36. Synthesis of δ-thiolactams.

Scheme 37. Synthesis of methyl-4-alky1-3-hydroxybenzoates.

Scheme 38. Synthesis of functionalized benzo[c]chromen-6-one core.

Scheme 39. Synthesis of triarylated pyrimidine derivatives.

Scheme 40. Synthesis of E-α,β-unsaturated esters.

Scheme 41. Synthesis of 1,3-dioxolanes (A) and Baylis–Hillman product (B).

Scheme 42. Synthesis of spirocyclic oxindole dihydrothiophene.

Scheme 43. Synthesis of 1,2,3,4-tetrahydrodibenzo[b,d]furan motifs.

Scheme 44. Synthesis of protected β-amino acids.

Scheme 45. Synthesis of β-amino esters/α–fluoro-β-amino esters.

Scheme 46. Synthesis of (S)-N-tert-butanesulfinylfluoroacetaldimine compounds.

Scheme 47. Synthesis of biphenyls.

Scheme 48. Synthesis of flavones and aurones.

Scheme 49. Synthesis of 1,4-disubstituted 1,2,3-triazoles.

Scheme 50. Synthesis of ketones.

Scheme 51. Synthesis of α-aminonitriles and cyanohydrins.

Scheme 52. Synthesis of methyl-H-phosphinate esters.

Scheme 53. Synthesis of the methylation of bezimidazoles, phenols and indoles.

Scheme 54. Synthesis of α-alkylation of enones.

Scheme 55. Synthesis of functionalized oxazoles.

Scheme 56. Synthesis of 1,3-diketones/α,β-unsaturated-1,3-diketones.

Scheme 57. Synthesis of O-acyl cyanohydrin adducts.

Scheme 58. Synthesis of α-diketones.

Scheme 59. Synthesis of 4-Azalactone.

Scheme 60. Synthesis of cyclic hemiacetals.

Scheme 61. Synthesis of 2-amino-4-aryl-6,7,8,9-tetrahydro-5H-benzo[7]annu-lene-1,3-dicarbonitriles.

Scheme 62. Synthesis of pyrrolo[2,1-a]isoquinolines.

Scheme 63a. Synthesis of spiropyrans.

Scheme 63b. The plausible mechanism.

Scheme 64. Synthesis of N-Aryl quinoline analogues.

Scheme 65. A diastereoselective synthesis of pyrano fused coumarins.

Scheme 66. Synthesis of 2-thioxo-2,3-dihydroquinazoline-4(1H)-ones.

Scheme 67a. Synthesis β-oxoalkyl carbamates.

Scheme 67b. Mechanism.

Scheme 68. Synthesis highly functionalized pyridine derivatives.

Scheme 69. Synthesis of substituted chromenes and pyranes.

Scheme 70. Synthesis of 2-amino-4-(nitroalkyl)-4H-chromene-3-carbonitriles.

Scheme 71. Synthesis of spiropyrazolone derivatives.

Scheme 72. Synthesis of 4H-pyrimido[2,1-b]benzothiazoles.

Scheme 73. Synthesis of quinazoline-2,4-(1H,3H)-diones.

Scheme 74. Synthesis of 2-benzoxazolones.

Scheme 75. Synthesis of carbomethoxylation of the alcoholic groups of phenols.

Scheme 76. Synthesis of hydantoins.

Scheme 77. Synthesis of N-alkyl carbamates.

Scheme 78. Synthesis of 2-benzimidazolones.

Scheme 79a. Synthesis of carbamates.

Scheme 79b. The plausible mechanism.

Scheme 80. Synthesis of cyclic carbonates.

Scheme 81. Synthesis of methyl-O-benzyl carbonothioates.

Scheme 82. Synthesis of S-alkyl carbonothioates.

Scheme 83. Synthesis of quinazolinones.

Scheme 84a. Synthesis of N-phenoxycarbonylation of N-heteroaromatics.

Scheme 84b. The plausible mechanism.

Scheme 85a. Synthesis of (E)-3-(2S,3R-O-isopropylidene-2,3-dihydrofuran-5-yl)-1-phenyl-prop-2-ene-1-ones.

Scheme 85b. The plausible mechanism.

Scheme 86. Synthesis of Danishefsky-Type diene.

Scheme 87. Synthesis of pyrazole-5-carboxylates.

Scheme 88. Bronsted basic characteristics of DBU.

Scheme 89. Synthesis of (3E,5E)-6,10-dimethylundeca-3,5,9-trien-2-one.

Scheme 90. Synthesis of α-keto esters of cyclopent-2-enon.

Scheme 91. Synthesis of 2/3-azachalcones.

Scheme 92. Synthesis of ketene silyl acetals.

Scheme 93. Synthesis of cyclopent-2-ene/ cyclohex-2-ene ketene silyl acetals.

Scheme 94. Synthesis of 2-alkylamino-3-nitro-4-alkylsulfanyl-4H-chromenes.

Scheme 95. Synthesis of enantiopure spiro-cycloadducts.

Scheme 96. Synthesis of 1H-quinazoline-2,4-diones.

Scheme 97. The stereoselective Michael addition reaction between chiral 5-glyco-4-nitrocyclohex-1-enes.

Scheme 98. Michael addition of glycine amines to aromatic nitroalkenes.

Scheme 99. Synthesis of spirocyclic-2-oxindole derivatives.

Scheme 100. Synthesis of 4H-pyrans.

Scheme 101. Synthesis of γ-nitro aliphatic methyl esters.

Scheme 102. Aza-Michael addition of α,β-unsaturated carbonyl compounds.

Scheme 103. Aza-Michael addition of amines to α,β-unsaturated compounds.

Scheme 104. Stereoselective synthesis of 1-amino-2,5-diarylcyclohexanecarboxylic acid derivatives.

Scheme 105. Synthesis of cyclic α,β-unsaturated butenolides and pyrazolones.

Scheme 106. Synthesis of 2,3,5-trisubstituted furans.

Scheme 107. Synthesis of functionalized 2H-1-benzopyrans.

Scheme 108. Synthesis of γ-lactams.

Scheme 109. Synthesis of 2-aryl-2H-indazoles.

Scheme 110. Synthesis of β-amino-α-diazocarbonyls/β-hydroxy-α-diazocarbonyls.

Scheme 111a. Annulation of 1-substituted-3-en-1-yn-5-als with cycloalkanones.

Scheme 111b. The plausible mechanism.

Scheme 112. Synthesis of nitriles.

Scheme 113. Synthesis of 1,4,5-trisubstituted-1,2,3-triazoles.

Scheme 114. Synthesis of β-hydroxy-α-arylacrylates.

Scheme 115. Synthesis of β-aminosulfonylimidates.

Scheme 116. Synthesis of fused 1,2,3-triazoles.

Scheme 117. Synthesis of N¹-substituted 1H-indazoles.

Scheme 118. Synthesis of spirooxindole derivatives.

Scheme 119. Synthesis of Substituted 1,2,3-triazoles.

Scheme 120. Synthesis of isatin-incorporated phosphate-bearing 1,6-adducts.

Scheme 121a. Synthesis of 3,4-dihydropyranones.

Scheme 121b. The plausible mechanism.

Scheme 122. Synthesis of 1,2,3-triazoles.

Scheme 123. Synthesis of carbamic acids and urea.

Scheme 124. Synthesis of S-Fm (Fm: 9-Fluorenylmethyl) protected peptides.

Scheme 125a. Synthesis of γ-hydroxy-α-enones.

Scheme 125b. A possible mechanism of the role of DBU in this rearrangement.

Scheme 126. Synthesis of tetrasubstituted thiophenes.

Scheme 127. Synthesis of novel tetramic acid derivatives.

Scheme 128. Synthesis of a novel series of anthracene-9,10-dione derivatives.

Scheme 129. Synthesis of allylic benzoates.

Scheme 130. 1,3,2-oxathiaphospholane ring opening condensation reaction with selected C-, O-, S-, and N- nucleophiles.

Scheme 131. Synthesis of nitriles.

Scheme 132. Synthesis of 4-vinylphenols.

Scheme 133. Synthesis of symmetrical diarylamines.

Scheme 134. Synthesis of terminal aryl- and styryl-acetylenes.

Scheme 135. Synthesis of arylacetylenes and 1,3-enynes.

Scheme 136. Synthesis of multisubstituted 2,3-dihydro-4H-quinolizin-4-ones.

Scheme 137. Synthesis of vicinal diamine-containing heterocycle derivatives.

Scheme 138. Synthesis of 5,7-disubstituted-1,2,4-triazolo[1,5-a]pyrimidines.

Scheme 139. Synthesis of 2,6-dione derivatives.

Scheme 140. Synthesis of biodegradable aliphatic polyesters, such as poly(lactic-co-glycolic acid) (PLGA).