Highly Enantioselective Three-Component Direct Mannich Reactions of Unfunctionalized Ketones Catalyzed by Bifunctional Organocatalysts

A highly stereoselective three-component direct Mannich reaction between aromatic aldehydes, <i>p</i>-toluenesulfonamide, and unfunctionalized ketones was achieved through an enolate mechanism for the first time with a bifunctional quinidine thiourea catalyst. The corresponding <i>N</i>-tosylated β-aminoketones were obtained in high yields and excellent diastereo- and enantioselectivities (up to >99:1 dr and >99% ee)

Highly Enantioselective Three-Component Direct Mannich Reactions of Unfunctionalized Ketones Catalyzed by Bifunctional Organocatalysts

A highly stereoselective three-component direct Mannich reaction between aromatic aldehydes, <i>p</i>-toluenesulfonamide, and unfunctionalized ketones was achieved through an enolate mechanism for the first time with a bifunctional quinidine thiourea catalyst. The corresponding <i>N</i>-tosylated β-aminoketones were obtained in high yields and excellent diastereo- and enantioselectivities (up to >99:1 dr and >99% ee)

Acetylphosphonate as a Surrogate of Acetate or Acetamide in Organocatalyzed Enantioselective Aldol Reactions

Highly enantioselective aldol reactions of acetylphosphonates and activated carbonyl compounds was realized with cinchona alkaloid derived catalysts, in which the acetylphosphonate was directly used as an enolate precursor for the first time. The aldol product obtained was converted in situ to its corresponding ester or amide through methanolysis or aminolysis. The overall process may be viewed as formal highly enantioselective acetate or acetamide aldol reactions, which are very difficult to achieve directly with organocatalytic methods

Highly Stereoselective Synthesis of Trisubstituted Cyclohexanols Using a Guanidine-Catalyzed Tandem Henry–Michael Reaction

A highly diastereoselective (dr >99:1) and enantioselective (ee value up to 98%) synthesis of trisubstituted cyclohexanols was achieved by using a tandem Henry–-Michael reaction between nitromethane and 7-oxo-hept-5-enals catalyzed by the Misaki–Sugimura guanidine

Acetylphosphonate as a Surrogate of Acetate or Acetamide in Organocatalyzed Enantioselective Aldol Reactions

Highly enantioselective aldol reactions of acetylphosphonates and activated carbonyl compounds was realized with cinchona alkaloid derived catalysts, in which the acetylphosphonate was directly used as an enolate precursor for the first time. The aldol product obtained was converted in situ to its corresponding ester or amide through methanolysis or aminolysis. The overall process may be viewed as formal highly enantioselective acetate or acetamide aldol reactions, which are very difficult to achieve directly with organocatalytic methods

Acetylphosphonate as a Surrogate of Acetate or Acetamide in Organocatalyzed Enantioselective Aldol Reactions

Highly enantioselective aldol reactions of acetylphosphonates and activated carbonyl compounds was realized with cinchona alkaloid derived catalysts, in which the acetylphosphonate was directly used as an enolate precursor for the first time. The aldol product obtained was converted in situ to its corresponding ester or amide through methanolysis or aminolysis. The overall process may be viewed as formal highly enantioselective acetate or acetamide aldol reactions, which are very difficult to achieve directly with organocatalytic methods

Highly Stereoselective Synthesis of 2,6-<i>cis</i>-Substituted Tetrahydropyrans Using a One-Pot Sequential Catalysis

A catalytic highly diastereo- and enantioselective synthesis of 2,6-<i>cis</i>-substituted tetrahydropyrans was realized using a one-pot sequential catalysis involving Henry and oxa-Michael reactions. The nitroaldol products obtained in a highly enantioselective copper(II)-catalyzed Henry reaction between nitromethane and 7-oxo-hept-5-enals were subsequently treated with a catalytic amount of camphorsulfonic acid (CSA) to give the desired tetrahydropyran derivatives in excellent yields, diastereoselectivities (dr >99:1), and enantioselectivities (ee = 98–99%). The reaction can also be used for the high stereoselective synthesis of a <i>cis</i>-2,6-disubstituted morpholine

Highly Interpenetrated Robust Microporous Hydrogen-Bonded Organic Framework for Gas Separation

A hydrogen-bonded organic framework (HOF), HOF-11, has been successfully prepared by the slow diffusion of hexane into a tetrahydrofuran solution of tris­(4-carboxyphenyl)­amine (TCPA). HOF-11 has been characterized by single-crystal and powder X-ray diffraction analysis, which is composed of TCPA ligands connected by the intermolecular hydrogen-bonding interactions in the carboxylic group dimer, showing 11-fold interpenetrated three-dimensional hydrogen-bonded networks in a (10,3)-b topology with the pore size of 6.2 × 6.8 Ų. The permanent porosity of degassed HOF was demonstrated by virtue of the CO₂ sorption and selective gas adsorption

A Homochiral Microporous Hydrogen-Bonded Organic Framework for Highly Enantioselective Separation of Secondary Alcohols

A homochiral microporous hydrogen-bonded organic framework (HOF-2) based on a BINOL derivative has been synthesized and structurally characterized to be a uninodal 6-connected {3³5⁵6⁶7} network. This new HOF exhibits not only a permanent porosity with the BET of 237.6 m² g^–1 but also, more importantly, a highly enantioselective separation of chiral secondary alcohols with ee value up to 92% for 1-phenylethanol

A Homochiral Microporous Hydrogen-Bonded Organic Framework for Highly Enantioselective Separation of Secondary Alcohols

A homochiral microporous hydrogen-bonded organic framework (HOF-2) based on a BINOL derivative has been synthesized and structurally characterized to be a uninodal 6-connected {3³5⁵6⁶7} network. This new HOF exhibits not only a permanent porosity with the BET of 237.6 m² g^–1 but also, more importantly, a highly enantioselective separation of chiral secondary alcohols with ee value up to 92% for 1-phenylethanol