RESUMO
In this review, we summarize some of the most recent advances in the construction of cyclic compounds from the annulation of Morita-Baylis-Hillman (MBH) adducts, which have demonstrated their importance by possessing diverse functional groups. Significant examples including [3 + 2], [3 + 3], [3 + 4] and other cyclizations described herein with MBH adducts were proven to be efficient approaches for the preparation of diverse cyclic structure motifs. However, most of the reported strategies are based on the use of non-chiral catalysts/ligands, whilst stereoselective reactions remain largely unexplored. This area is still in its infancy and future research on MBH adducts will definitely benefit the organic chemistry community, especially for the synthesis of drug candidates and other molecules that might draw attention to materials sciences.
RESUMO
An organocatalytic [3 + 2]-annulation between isatin-derived Morita-Baylis-Hillman adducts and cyclic sulfonimines has been developed in high yields with excellent enantio- and diastereoselectivities via an allylic nitrogen-ylide intermediate. The reaction provides access to heavily substituted aza-spirooxindole derivatives, which also contain ring fused cyclic sultams.
Assuntos
Isatina/química , Compostos de Sulfidrila/química , Catálise , Estrutura Molecular , EstereoisomerismoRESUMO
An enantioselective [3+2] annulation of Morita-Baylis-Hillman carbonates with trifluoropyruvate catalyzed by modified cinchona alkaloids was developed in good to excellent yields with excellent diastereo- and enantioselectivities.
Assuntos
Aminas/química , Carbonatos/química , Isatina/química , Ácido Pirúvico/química , Catálise , Estereoisomerismo , Especificidade por SubstratoRESUMO
The reaction of Morita-Baylis-Hillman (MBH) alcohols with Me2PhSiBpin under the catalysis of Cu(OTf)2/pyridine in methanol has been developed. The direct silylation of allylic alcohols via dual activation of the Si-B bond and the hydroxyl group of the MBH alcohol provides an efficient and convenient method for the synthesis of functionalized allylsilanes.
Assuntos
Álcoois/química , Mesilatos/química , Silanos/química , Silanos/síntese química , Catálise , Estrutura Molecular , EstereoisomerismoRESUMO
An enantioselective tandem reaction of chromones-derived MBH carbonates (1) with benzylamines (2) catalyzed by a trifunctional organocatalyst, cinchonidine-amide-thiourea, has been developed in moderate to good yields (50-87%) and enantioselectivities (up to 89% ee).
Assuntos
Benzilaminas/química , Carbonatos/química , Flavanonas/síntese química , Amidas/química , Catálise , Cromonas/química , Alcaloides de Cinchona/química , Estereoisomerismo , Tioureia/químicaRESUMO
A Me-DuPhos-catalyzed efficient asymmetric [3 + 2] cycloaddition reaction between Morita-Baylis-Hillman carbonates of isatins and N-phenylmaleimide has been developed. This reaction constructs three chiral centers in one step to afford spirocyclopentaneoxindoles in good yields (up to 84%) with excellent diastereo- and enantioselectivies (up to 99% ee).