New advances in dual stereocontrol for asymmetric reactions

Enantioselective Desymmetrization via Carbonyl-Directed Catalytic Asymmetric Hydroboration and Suzuki–Miyaura Cross-Coupling

“…Furthermore, these phosphoramidites generally give the enantiomeric product compared to that obtained with corresponding phenyl phosphite; enantioselectivity as high as 78% ee for (1 S ,3 R )- 6a is found using L3c . The results are in qualitative agreement with our previous report of exceptionally high levels of enantioswitching 15 with the acyclic substrate 1 . 11d …”

Enantiodivergent Steglich rearrangement of O-carboxylazlactones catalyzed by a chirality switchable helicene containing a 4-aminopyridine unit

“…1 To date, several enantiodivergent catalytic systems under various conditions have been reported, in which the chiral environment of the complementary transition states can be tuned. For instance, reaction temperatures, 2 solvent effects, 3 achiral co-catalysts, 4 structural modifications of functional substrates, 5 and different coordinating metal ions 6 were found to facilitate enantiodivergent catalyses with good to high enantioselectivities (89–97% ee).…”

Cooperative Guanidinium/Proline Organocatalytic Systems

“…In addition, the small amount of syn-adducts produced in the absence of guanidinium salt 5b featured the absolute configuration (S,S), opposite to the examples shown in Table 5. These observations demonstrated how the participation of the guanidinium salt controls the stereopreference of the aldol reaction (for a general review on the stereocontrol of asymmetric reactions, including organocatalyzed transformations, see [93]). To our knowledge, only Yang and co-workers have presented another Fig.…”