Bis(phosphinoamides) based on sugars for highly enantioselective allylic substitution: inversion of stereocontrol by switching from glucose to mannose

Catalytic sugar-assisted transfer hydrogenation with Ru(II), Rh(III) and Ir(III) halfsandwich complexes

“…This concept enables the preparation of carbohydrate ligands with enantiomeric properties in catalytic reactions without using the rare and costly carbohydrate enantiomers. The same effect has been described by Ruffo and coworkers in the palladium catalyzed desymmetrisation of meso-cyclopent-2-ene-1,4-diol by means of 2,3-diamino-glucose-and -mannose derivatives [47].…”

Carbohydrates as enantioinduction components in stereoselective catalysis

“…For example, Ruffo and co-workers accessed 7 by amide coupling of carboxylic acid containing phosphine 6 with protected 2,3-glucodiamine 5 ( Scheme 2 ). 12 Given that 7 closely resembles the highly successful Trost Ligand, 13 it was unsurprising that it performed efficiently in Pd-catalysed asymmetric allylic alkylation (AAA) reactions. For example, desymmetrisation of 8 proceeded smoothly to generate carbamate 9 in excellent yield and 97% ee.…”

“…A d -mannose derived pseudo-enantiomeric variant of 7 was also reported. 12 It is pertinent to note that diamine 5 has also been used in the synthesis of salen ligands for Mn-catalysed epoxidation of styrenes. 14 …”

More Than Just Sweet - Sugar-Derived Stereodifferentiating Agents for Asymmetric Synthesis

“…99 This ligand yielded the product (3R,6S)-162 in excellent stereoselectivity, and by slight modification of the ligand structure the result could even be improved. The same research group also successfully employed D-glucoand D-manno-configured 2,3-diamino ligands for palladium-catalysed desymmetrisations 100 and molybdenum-catalysed allylic substitutions. 101 A simplified version of ligand 136, containing only one phosphorus donor centre (163b) also gave high enantiomeric excess in common allylic substitutions, 102 an even simpler ligand (163a) had been previously reported by Sinou and Framery, 103 giving an almost identical result (Scheme 33).…”