Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• spirooxindoles, in which the in situ-generated Michael adduct of 3-ethoxycarbonylmethyleneoxindole underwent a Mannich reaction and annulation reaction with in situ-generated aldimines (reaction 1 in Scheme 1) [50][51]. Tanaka reported chiral quinidine derivative-catalyzed Michael–Henry cascade reactions of

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• enantioselectivity (47–98% ee). The observed results were rationalized with density functional theory calculations (Table 8) [42]. 1.3 Reactions catalyzed by chiral amines He and co-workers developed heterogeneous synergistic catalysis using chiral amines SBA-15 (cat. 44), which promote aza-Michael–Henry cascade

• reactions between 2-aminobenzaldehydes 42 and β-nitrostyrenes 43 to obtain chiral 3-nitro-1,2-dihydroquinolines 45 in good yields with up to 98% ee (Table 9) [43]. 1.4 Reactions catalyzed by chiral phase-transfer catalysts Chiral phase-transfer catalysts (PTC) have been recognized as versatile catalysts for

Construction of highly enantioenriched spirocyclopentaneoxindoles containing four consecutive stereocenters via thiourea-catalyzed asymmetric Michael–Henry cascade reactions

• Yonglei Du,
• Jian Li,
• Kerong Chen,
• Chenglin Wu,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2017, 13, 1342–1349, doi:10.3762/bjoc.13.131

• spirocyclopentaneoxindoles. Keywords: asymmetric synthesis; four consecutive stereocenters; Michael–Henry cascade reactions; spirocyclopentaneoxindoles; thioureas; Introduction The spirocyclic oxindole core represents an important scaffold that is encountered frequently in many biologically active molecules and natural

• [35] (Scheme 1, reaction 1A) and Michael–Henry cascade reactions [25] (Scheme 1, reaction 1B) reported by Barbas III's group involve the cyclization between α,β-unsaturated aldehydes and nitrostyrenes with 3-substituted oxindoles to generate the corresponding CHO- or NO2-substituted spirooxindole

• stereocenters and a unique quaternary stereogenic center, with good yields, and excellent diastereoselectivity and enantioselectivity using thiourea-catalyzed Michael–Henry cascade reactions. We anticipate that this reaction will simplify the synthesis of complex spirooxindoles containing multiple chiral