1H-Imidazol-4(5H)-ones and thiazol-4(5H)-ones as emerging pronucleophiles in asymmetric catalysis

• Antonia Mielgo and
• Claudio Palomo

Beilstein J. Org. Chem. 2016, 12, 918–936, doi:10.3762/bjoc.12.90

• the main focus has been directed not only to the search for new efficient chiral catalysts, but also to the development of efficient pronucleophiles. This review highlights the utility and first examples of 1H-imidazol-4(5H)-ones and thiazol-4(5H)-ones as pronucleophiles in catalytic asymmetric

• reactions. Keywords: asymmetric catalysis; bifunctional catalysts; 1H-imidazol-4(5H)-ones; pronucleophiles; thiazol-4(5H)-ones; Introduction Asymmetric catalysis [1][2][3] constitutes a very powerful tool for the preparation of enantiomerically pure compounds [4]. Recent efforts in the field have been

• -additions to allenic ketones and esters [35][36], 1,6-additions to conjugated dienones [37], aldol/Mannich reactions [26][38][39][40], α-sulfenylation reactions [41] and alkylations [42][43]. More recently the nitrogen (1H-imidazol-4(5H)-ones, Figure 1b, X = NR’) and sulfur (thiazol-4(5H)-ones, Figure 1b, X