The development of novel synthetic strategies to form new chemical entities in a stereoselective manner is an ongoing significant objective in organic and medicinal chemistry. This review analyses the development of new stereoselective approaches to spirocyclic oxindoles with spiro-3- to 8-membered rings. It highlights the importance of these structures for applications in medicinal chemistry, as intermediates or final products in total synthesis and as model compounds for the development of enantioselective catalytic methodologies.

Stereoselective synthesis and applications of spirocyclic oxindoles

A sequential and general strategy has been successfully developed for the synthesis of spiropyrazolone scaffolds. This intriguing transformation of the asymmetric multicomponent catalysis process was realized with the combination of Michael addition/chlorination/nucleophilic substitution in a one-pot sequence, giving rise to a series of spiropyrazolones with fully substituted cyclopropanes and spiro-dihydrobenzofurans containing continuous stereogenic centers in good yields with excellent stereoselectivities.

One-Pot Asymmetric Synthesis of Spiropyrazolone-Linked Cyclopropanes and Benzofurans through a General Michael Addition/Chlorination/Nucleophilic Substitution Sequence

A highly straightforward route to enantiomerically enriched spiro-benzofuran pyrazolones has been achieved via chiral amine squaramide catalyzed [4 + 1] annulation of in situ generated ortho-quinomethanes with the novel C1 synthons of 4-halo pyrazolones. In oil–water biphases, high yields (up to 95%) and high to excellent stereoselectivities (up to 99 : 1 dr, 99% ee) of the resulting 4-spiropyrazolones with a wide substrate scope could be achieved. Furthermore, the present protocol provided an arbitrary access to all four possible stereoisomers of the spiro-benzofuran pyrazolones via an appropriate choice of C1 synthons and chiral catalysts.

Organocatalytic asymmetric [4 + 1] annulation of in situ generated ortho-quinomethanes with 4-halo pyrazolones: straightforward access to chiral spiro-benzofuran pyrazolones

An unexpected cascade reaction of 3-hydroxyoxindoles with coumarin-3-carboxylates to construct 2,3-dihydrobenzofuran spirooxindoles.

Chiral Phosphoric Acid Catalyzed (4+1) Annulation of 3-Diazooxindoles/4-Diazooxisoquinolines with para-Quinone Methides to Access Chiral Spiro[dihydrobenzofuran-2,3′-oxindoles/2,4′-oxisoquinolines]

Combining Organocatalysis and Iodine Catalysis: One-Pot Sequential Catalytic Synthesis of Chiral Spirodihydrobenzofuran Pyrazolones and Spirodihydrobenzofuran Oxindoles.

[Cp*IrCl2]2 with a phosphine-free ligand α,α,α-terpyridine shows high catalytic performance in chemodivergent synthesis of α-alkylated arylacetonitriles in the presence of K2CO3 and α-alkylated acetamides in the presence of tBuOK, respectively.

Base-controlled chemoselectivity: direct coupling of alcohols and acetonitriles to synthesise α-alkylated arylacetonitriles or acetamides

Synthesis and Properties of Sodium Fatty Acyl Lactylates

Investigation on the phase behaviors of aqueous surfactant two-phase systems containing Alkyl polyglucosides (APG) and alkyl polyglucoside sulfosuccinate (APGSS)

The scientific community has shown a great deal of interest in sodium lauroyl glycine (SLG) and sodium lauroyl lactylate (SLL), two sustainable and eco-friendly substances that are considered as potential bio-friendly alternatives for petrochemical-based amphiphiles. In the present work, the formation of mixed micelle for SLG and SLL surfactant in water was investigated. Meanwhile, the surface interaction and thermodynamic parameters were calculated according to the surface tension curves. The results indicated that at certain ratios, SLG/SLL surfactant mixtures had synergistic effects that could yield higher surface activity and improve application performance. When the mole fraction of SLL (αSLL) was 0.4, γcmc achieved a minimum of 22.6 mN m-1 and displayed the best foaming properties. The mixed solution exhibited the best wetting ability when αSLL was 0.6. While αSLL was 0.8, the mixed solution showed the optimum dynamic adsorption properties. And it was found that the antibacterial property of SLG and SLL could be partially preserved after compounding. These results demonstrated for the first time that the mixed environmentally friendly surfactant SLG and SLL has a promising prospect for use in the personal care, detergent, and cosmetic industries.

Liang Bai

Papers

Combining Organocatalysis and Iodine Catalysis: One-Pot Sequential Catalytic Synthesis of Chiral Spirodihydrobenzofuran Pyrazolones and Spirodihydrobenzofuran Oxindoles.

Base-controlled chemoselectivity: direct coupling of alcohols and acetonitriles to synthesise α-alkylated arylacetonitriles or acetamides

Synthesis and Properties of Sodium Fatty Acyl Lactylates

Investigation on the phase behaviors of aqueous surfactant two-phase systems containing Alkyl polyglucosides (APG) and alkyl polyglucoside sulfosuccinate (APGSS)

Study on the Properties of the Sodium Lauroyl Glycinate and Sodium Lauroyl Lactylate Composite System.