Tandem Michael-Michael Research Articles

Diversified Stitching of Ynones with Oxindole-3-oxy acrylates: One-Flask Spiro-annulation Protocol toward Assorted 3H/5H-Spiro[furan-2,3'-indolin]-2'-ones.

Spiroannulation of oxindole-3-oxy acrylates with ynones involving two overlapping, base differentiated cascades has been observed. Initial exposure of ynones and oxindole 3-oxy acrylates to K2CO3 triggered a tandem Michael-Michael cascade to deliver a pair of spiroannulated diastereomers. Further exposure to LiHMDS led to deep restructuring through a second multistep cascade involving stereoselective recreation of the C3 quaternary center to furnish 3H-spiro[furan-2,3'-indolin]-2'-ones with functional amplification and scrambling. This new scaffold can be directly accessed in a one-flask operation from ynones and oxindole-3-oxy acrylates.

ChemInform Abstract: Stereoselective Synthesis of Spirooxindole Derivatives Using an Organocatalyzed Tandem Michael—Michael Reaction.

A highly efficient stereoselective method for the synthesis of functionalized spirooxindole derivatives with three stereogenic centers was realized through an organocatalytic tandem Michael-Michael reaction. By employing (S)-α,α-diphenylprolinol trimethylsilyl ether as the catalyst and N,N'-bis[3,5-bis(trifluoromethyl)phenyl]thiourea as the cocatalyst, the reaction between N-tritylisatylidenemalononitriles and (E)-7-alkyl-7-oxohept-5-enals yields the desired spirooxindole products in good yields (76-95%) and with excellent diastereoselectivities (up to 97 : 3 dr) and enantioselectivities (up to 98% ee), which can be stereoselectively converted into the spiro[indoline-3,8'-isoquinoline] derivative through an intramolecular reductive amination reaction.

Diastereoselective Synthesis of Bicyclo[2.2.2]octan-2-one Derivatives through an Unexpected Organocatalytic Tandem Michael-Michael Reaction

An organocatalytic tandem Michael-Michael reaction is developed for the simple preparation of stereo complex, polycyclic compounds from simple reactants in satisfactory yields (up to 90%) and excellent diastereoselectivities (>30:1 dr).

Stereoselective desymmetrisation of prochiral α,α-dicyanoalkenes via domino Michael–Michael addition reactions

The desymmetrisation of prochiral alpha,alpha-dicyanoalkenes via tandem Michael-Michael addition reactions with alpha,beta-unsaturated ketones catalysed by 9-amino-9-deoxyepicinchona alkaloids was investigated, from which bicyclic products bearing four stereogenic centers were afforded in a single operation with high stereoselectivities (>99% de, up to >99.5% ee).

A highly diastereoselective tandem Michael-Michael addition reaction in a rotameric ring system: steric acceleration due to conformation locking

A highly diastereoselective one-pot tandem Michael-Michael addition reaction developed in a rotamerically locked conformation is described. Reaction of isocyanates 8 – 13 with hydroxylactone 14 gave tandem Michael-Michael adducts 22 – 26 in good to excellent yields. The intermediate tricyclic oxazolidinones consisted of rotamer pairs 16 – 19, and the rotation barriers of some of these compounds were determined. The tandem addition reaction was highly accelerated by introducing conformation anchoring group X. A new versatile synthesis of octahydroacridines 27 – 29 using the tandem adducts is also described.