Novel organic catalysts for the direct enantioselective α-oxidation of carbonyl compounds

Direct organocatalytic Wittig/Hetero-Diels-Alder reactions in one-pot: synthesis of highly-substituted tetrahydropyranones

“…[11][12][13] Also, Jørgensen and Juhl developed the enantioselective inverse-electron-demand HDA reaction with an enamine generated in situ from an aldehyde and chiral amine with enones under organocatalysis. [14][15][16][17][18] As part of our program to engineer novel asymmetric assembly reactions that proceed in environmentally-sound conditions under amine-catalysis, 8,[19][20][21][22][23][24][25][26][27] we sought to extend the use of chiral organo-amines as catalysts for asymmetric HDA reactions.…”

Highly Enantioselective α-aminoxylation Reactions Catalyzed by Isosteviol-proline Conjugates in Buffered Aqueous Media

“…The scope of the L-proline-catalyzed reaction was then extended to ketones by Hayashi [10] and Córdova [11,12]. After this initial breakthrough in the organo-catalyst field, several modified L-proline catalysts have been developed to improve the enantioselectivity and reactivity, such as 4-siloxyproline [13], polymers-supported prolines [14], a,a-diphenylprolinol trimethylsilyl ether [15] and the substitution of the carboxylic acid moiety of L-proline with an amide [16][17][18] or tetrazole function [19]. However, most of the reported catalytic reactions were carried out in organic solvents such as DMSO, DMF, CH 3 CN, CHCl 3 , CH 2 Cl 2 , etc., and little work was done considering environmentally friendly reaction protocols.…”

The Role of Oxazolidinones in l-Proline-Assisted Aldol-Type Reactions

“…Recently, a new class of catalytically active species, called organocatalysts, has emerged as a potential substitute for the traditionally employed catalysts [7][8][9]. L-proline, an amino acid, is among the simplest and most studied organocatalysts which has been shown to promote a wide range of organic reactions [8][9][10][11][12][13][14][15][16][17][18][19][20].…”

“…Recently, a new class of catalytically active species, called organocatalysts, has emerged as a potential substitute for the traditionally employed catalysts [7][8][9]. L-proline, an amino acid, is among the simplest and most studied organocatalysts which has been shown to promote a wide range of organic reactions [8][9][10][11][12][13][14][15][16][17][18][19][20]. Its advantages as a catalyst include operation at a low temperature, high yield and enantioselectivity, as well as excellent atom efficiency [8][9][10][11][12][13][14][15][16][17][18].…”

“…L-proline, an amino acid, is among the simplest and most studied organocatalysts which has been shown to promote a wide range of organic reactions [8][9][10][11][12][13][14][15][16][17][18][19][20]. Its advantages as a catalyst include operation at a low temperature, high yield and enantioselectivity, as well as excellent atom efficiency [8][9][10][11][12][13][14][15][16][17][18]. Nevertheless, the industrial application of L-proline is limited by high catalyst loadings, long reaction times and a low turnover number [8][9][10][11][12][13][14][15][16][17][18].…”