Carbohydrate-Based Chiral Iodoarene Catalysts: A Survey through the Development of an Improved Catalyst Design

Abstract

Iodoarene catalysts can be applied in versatile reactions, for instance in the construction of complex chiral molecules via dearomatization of simple aromatic compounds. Recently, we reported the synthesis of the first carbohydrate-based chiral iodoarene catalysts and their application in asymmetric catalysis. Here we describe the synthesis of some new and improved catalysts. An account on how we got to the improved catalyst design, as well as the X-ray structure of one of the carbohydrate-based iodoarenes, is given.

Asymmetric Direct/Stepwise Dearomatization Reactions Involving Hypervalent Iodine Reagents

“…The Kita dearomative spirocycliztion and catalytic systems have been applied to further catalyst screening by other researchers, and the selected examples are shown in Figure 6. Imrich and Ziegler reported the one‐step syntheses of carbohydrate‐based chiral iodoarenes 36 from known compounds [44] . The catalyst (15 mol%) (R 1 =(1‐naphthyl)CH 2 ) afforded spirolactone 8 a in a 75% yield and enantiomeric ratio ( er ) of up to 88 : 12.…”

Access to d- and l-Psicose Derivatives via Hydroxy Methylation of Ribono Lactone

“…They can be synthesized either by isomerization of the corresponding aldoses in low yields or by multi-step syntheses involving different protection and deprotection steps or by enzymatic methods [2][3][4][5][6][7][8] resulting in a high price for these ketoses. As part of an ongoing research project about the synthesis of carbohydrate derived catalysts for asymmetric syntheses [9][10][11][12] we required considerable amounts of d-and l-psicofuranose derivatives 3. Due to the high price of both enantiomers of psicose [13] we developed a specific synthetic route for the preparation of d-and l-psicose derivatives 3, starting from d-and l-ribose (2).…”