Polymer-Supported Bases. XI. Esterification and Alkylation in the Presence of Polymer-Supported Bicyclic Amidine or Guanidine Moieties

TBD- or PS-TBD-Catalyzed One-Pot Synthesis of Cyanohydrin Carbonates and Cyanohydrin Acetates from Carbonyl Compounds

Cyanation reactions of carbonyl compounds with methyl cyanoformate or acetyl cyanide catalyzed by 5 mol % of 1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD) were examined. Using methyl cyanoformate, the corresponding cyanohydrin carbonates were readily obtained in high yield for aromatic and aliphatic aldehydes and ketones. Similar results were obtained when acetyl cyanide was used as the cyanide source. The polymer-supported catalyst, PS-TBD, also acted as a good catalyst for this reaction. PS-TBD was easily recovered and reused with minimal activity loss.

A Mild and Regioselective Ring-Opening of Aziridines with Acid Anhydride Using TBD or PS-TBD as a Catalyst

The ring-opening of N-tosylaziridines with various acid anhydrides catalyzed by 5 mol % of 1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD) afforded the corresponding β-amino esters in excellent yields under mild reaction conditions. Polymer-supported catalyst, PS-TBD also acts as a good catalyst for this reaction. PS-TBD was easily recovered and reused with minimal loss of activity.

Synthesis, characterization and catalytic activity of novel large network polystyrene-immobilized organic bases

In view of searching for efficient solid catalysts to be used in environmentally friendly reaction conditions, novel gel-type cross-linked polystyrenes functionalized with diethylamine and 1,5,7-triazabicyclo[4.4.0]dec-5-ene, have been prepared.

Ionic-liquid-supported 1,5,7-triazabicyclo[4.4.0]dec-5-ene — An efficient and recyclable organocatalyst for Michael addition to α,β-unsaturated ketones

A novel ionic-liquid-supported 1,5,7-triazabicyclo[4.4.0]dec-5-ene (IL–TBD) was synthesized and investigated for its ability to act as an active organocatalyst in the Michael addition of active methylene compounds and thiophenols to chalcones under solvent-free conditions. The IL–TBD afforded Michael addition products in excellent yields (82%–94%) at room temperature, and it was simply recycled and reused at least five times without significant loss of catalytic activity.

Parallel solution-phase synthesis of mechanism-based cysteine protease inhibitors

[reaction--see text] A seven-step parallel solution-phase synthesis has been developed for access to ketone-containing mechanism-based cysteine protease inhibitors. The use of liquid-liquid extractions, volatile or solid-supported reagents, and resin-bound scavengers eliminates the need for intermediate column chromatographic purification during this synthesis sequence.

Polymer supported bases in solution-phase synthesis. 2. A convenient method for N-alkylation reactions of weakly acidic heterocycles

A convenient solution-phase method for N-alkylation reactions of weakly acidic heterocycles employing polymer supported super base PBEMP is described. By using this method, multiple-step and chemoselective N-alkylation sequences can be carried out in a one-pot process.