A carboxy-directed asymmetric hydrogenation of α-alkyl-α-aryl terminal olefins was developed by using a chiral spiro iridium catalyst, providing a highly efficient approach to the compounds with a chiral benzylmethyl center. The carboxy-directed hydrogenation prohibited the isomerization of the terminal olefins, and realized the chemoselective hydrogenation of various dienes. The concise enanti...

Highly enantioselective protonation of α-halo and alkoxy carboxylic acid-derived ketene disilyl acetals is achieved by using P-spiro chiral diaminodioxaphosphonium barfate as a Brønsted acid catalyst, where the enantiofacial discrimination by the catalyst mainly stems from the recognition of the electronic difference between two substituents on the ketene disilyl acetal.

A novel axially chiral spiro-phosphine-catalyzed highly regio-, diastereo- and enantioselective [3+2] cycloaddition of alkylidene azlactones with various allenic esters has been developed, affording the corresponding functionalized spirocyclic products in moderate to excellent yields under mild conditions. These spirocyclic products as masked amino acids can be easily transformed into aspartic ...

Binaphthol-derived chiral ketones 1a-c were synthesized and were shown to serve as active catalysts for asymmetric epoxidation of olefins using Oxone®, although their enantioselectivities were not high. However, very interestingly, the stereochemical outcome of the resulting epoxides implicates that in the epoxidation using 1ac, the planar transition state may be more favorable than the spiro t...

Efficient catalytic asymmetric synthesis of 1,1-disubstituted tetrahydro-β-carbolines has been achieved via asymmetric alkylation of 1-cyanotetrahydro-β-carbolines using a binaphthyl-modified N-spiro-type chiral phase-transfer catalyst. This is a valuable example of hitherto difficult highly enantioselective alkylations at α-carbon of the cyano group under phase-transfer conditions.

A novel chiral spiro-pyrrolidine silyl ether organocatalyst has been designed. Its catalytic asymmetric effect is demonstrated by the Michael addition reaction, which affords the desired products with an all-carbon quaternary center in up to 99% ee and 87% yield. Furthermore, the reaction process has been investigated via in situ NMR experiments.

An easily available iron catalyst was developed to accomplish the C H functionalization of indoles with a-aryl-a-diazoesters in high yields under mild conditions. The asymmetric C H functionalization of indoles was also realized by using iron complexes of chiral spiro bisoxazolines with up to 78% ee.

An efficient and powerful organocatalytic cascade reaction was achieved for the synthesis of biologically important chiral spiro[pyrrolidin-3,2'-oxindoles] using very simple and readily available starting materials. Three C-C bonds and four contiguous stereogenic centers including one quaternary stereocenter were established in a single operation with reasonable yields and good stereoselectivity.

An efficient synthesis of spiropyrazolones based on organocatalysis is described. The reaction between pyrazolones, enolizable aldehydes and enals is catalyzed by secondary amine catalysts and affords the final spiro compounds bearing four contiguous chiral centers in good yields and excellent diastereo- and enantioselectivities.