A highly efficient large-scale asymmetric Michael addition of isobutyraldehyde to maleimides promoted by a novel multifunctional thiourea

Enantioselective Synthesis of Succinimides by Michael Addition of Aldehydes to Maleimides Organocatalyzed by Chiral Primary Amine‐Guanidines

“…The resulting crude residue was purified by flash chromatography ( n ‐hexane/AcOEt) to afford adducts 8 . Succinimides 8aa ,8b 8ab ,8f 8ac ,8b 8ad ,8f 8ae ,8f 8ag ,8b 8ah ,8b 8ba ,8a 8ca ,8c 8da ,8c 8ea ,8b and 8fa 3a have already been described, and their 1 H and 13 C NMR spectroscopic data and retention times from the chiral HPLC analyses of both enantiomers can be found in the Supporting Information. Full analytical and spectroscopic data as well as the observed retention times from chiral HPLC analyses of new compounds 8af and 8ai as well as oxidation product ( R )‐ 9ad are given below.…”

“…Therefore, other organocatalysts suitable for use with the challenging α,α‐disubstituted aldehydes to give enantioenriched succinimides that contain contiguous quaternary‐tertiary carbons were subsequently developed 1. The most common and successful have been those that incorporate both primary amine and thiourea moieties,8 such as the trifluoromethylated primary amine‐thioureas 1 ,8a,8b 2 ,8a,8b and 3 8e as well as beyerane‐containing thiourea 4 8f. However, noncovalent bifunctional organocatalysts based on the use of the primary amine of amino acids, combined with acid additives, have also been successfully used 9…”

1D Nickel Coordination Polymers with an Unnatural Amino Acid Prepared by in situ Double Michael Addition of Ethylenediamine to (E,E)‐Muconic Acid

“…Thus, the synthesis of new amino acids including dicarboxylic groups is of great importance in constructing new polymeric structures. In general, for the synthesis of amino acids, the Michael addition or Mannich reaction typically has been used to form C─N bonds by simple addition of amines to C=C double bonds …”

Highly EnantioselectiveMichael Addition Promoted by a New Diterpene‐Derived Bifunctional Thiourea Catalyst: A Doubly Stereocontrolled Approach to Chiral Succinimide Derivatives

“…Nevertheless, the skeleton structures to construct thiourea catalysts are very limited, and there is still great demand for novel bifunctional thiourea catalysts for this purpose. Recently, we found that, similar to the cinchona alkaloids, the incorporation of a chiral diterpene moiety (isosteviol) into the thiourea catalysts led to impressive results in asymmetric reactions . Inspired by the excellent chiral structural skeleton of isosteviol, we designed and synthesized a new class of primary amine‐thiourea bifunctional catalysts 3a and 3b .…”

“…Recently, we found that, similar to the cinchona alkaloids, the incorporation of a chiral diterpene moiety (isosteviol) into the thiourea catalysts led to impressive results in asymmetric reactions. [31][32][33][34][35][36][37] Inspired by the excellent chiral structural skeleton of isosteviol, we designed and synthesized a new class of primary amine-thiourea bifunctional catalysts 3a and 3b. With these novel catalysts in hand, the effects of the thiourea catalysts were investigated.…”