Acetone Cyanohydrin as a Source of HCN in the Cu-Catalyzed Hydrocyanation of α-Aryl Diazoacetates
作者:Eun Ju Park、Seungeon Lee、Sukbok Chang
DOI:10.1021/jo100356d
日期:2010.4.16
A procedure for the Cu-catalyzed hydrocyanation of α-aryl diazoesters has been developed using acetone cyanohydrin as a source of hydrogencyanide (HCN). It was found that the addition of trimethylsilyl cyanide (TMSCN) significantly accelerates the conversion presumably by delivering free cyanide ion in situ, thus producing various types of α-aryl cyanoacetates in high yields under mild conditions
<i>Cinchona</i>Alkaloid-Derived Thiourea-Catalyzed Diastereo- and Enantioselective [3+2] Cycloaddition Reaction of Isocyanoacetates to Isatins: A Facile Access to Optically Active Spirooxindole Oxazolines
作者:Mei-Xin Zhao、Hao Zhou、Wen-Hao Tang、Wei-Song Qu、Min Shi
DOI:10.1002/adsc.201300077
日期:2013.5.3
An efficient diastereo‐ and enantioselective [3+2] cycloaddition reaction of α‐aryl isocyanoacetates to isatins catalyzed by a quinine‐derived bifunctional amine‐thiourea‐bearing sulfonamide as multiple hydrogen‐bonding donor catalyst has been investigated. The corresponding adducts, which bear a spirocyclic quaternary stereocenter at the C‐3 position of the oxindole, were obtained in good yields (51–95%)
A nickel‐catalyzed asymmetric oxazole‐forming Ugi reaction of C,N‐cyclic azomethine imines and isonitriles is disclosed. The reported protocol proceeds smoothly, and gives the corresponding adducts, which contain two important pharmaceutically active ring‐systems (tetrahydroquinoline and oxazole rings), in good yields and excellent enantioselectivities by employing an easily accessible chiral diamine
<i>Cinchona</i> Alkaloid Squaramide/AgOAc Cooperatively Catalyzed Diastereo- and Enantioselective Mannich/Cyclization Cascade Reaction of Isocyanoacetates and Cyclic Trifluoromethyl Ketimines
作者:Mei-Xin Zhao、Hong-Lei Bi、Rong-Hui Jiang、Xu-Wei Xu、Min Shi
DOI:10.1021/ol502123z
日期:2014.9.5
An efficient diastereo- and enantioselective Mannich-type/cyclization cascade reaction of alpha-substituted isocyanoacetates and cyclic trifluoromethyl ketimines cooperatively catalyzed by cinchona alkaloid-derived multi-hydrogen-bonding donor squaramide and AgOAc has been investigated, affording the optically active trifluoromethyl-substituted tetrahydroimidazo[1,5-c]-quinazoline derivatives in excellent yields (up to 99%) and good to excellent stereoselectivities (up to >15:1 dr, up to 9896 cc) under mild conditions.
Cinchona Alkaloid Squaramide Catalyzed Enantioselective Hydrazination/Cyclization Cascade Reaction of α-Isocyanoacetates and Azodicarboxylates: Synthesis of Optically Active 1,2,4-Triazolines
作者:Mei-Xin Zhao、Hong-Lei Bi、Hao Zhou、Hui Yang、Min Shi
DOI:10.1021/jo401585v
日期:2013.9.20
An efficient enantioselective hydrazination/cyclization cascade reaction of alpha-substituted isocyanoacetates to azodicarboxylates catalyzed by Cinchona alkaloid derived squaramide catalysts has been investigated, affording the optically active 1,2,4-triazolines in excellent yields (up to 99%) and good to excellent enantioselectivities (up to 97% ee) under mild conditions.