NHC–Cu-Catalyzed Silyl Conjugate Additions to Acyclic and Cyclic Dienones and Dienoates. Efficient Site-, Diastereo- and Enantioselective Synthesis of Carbonyl-Containing Allylsilanes
作者:Kang-sang Lee、Hao Wu、Fredrik Haeffner、Amir H. Hoveyda
DOI:10.1021/om300790t
日期:2012.11.26
Efficient and highlydiastereo- and enantioselective conjugate additions of phenyldimethylsilyl units to acyclic and cyclic dienones and dienoates are disclosed. The C–Si bond forming reactions are catalyzed by 2.0–2.5 mol % of a coppercomplex of a chiral monodentate N-heterocyclic carbene; the requisite reagent, PhMe2Si–B(pin), is commercially available or can be easily prepared. Transformations
Synthesis of 2-substituted 3,4-dihydro-1,2-diazepines by the reactions of unsaturated ketones with hydrazides
作者:Patrick N. Anderson、Carl B. Argo、John T. Sharp
DOI:10.1039/p19810002761
日期:——
The previously reported synthesis of 3,4-dihydro-2-tosyl-1,2-diazepines by the acid-catalysed reactions of p-toluenesulphonylhydrazide with αβ,γδ-unsaturated ketones has been extended to other 2-substituted analogues (3) by the use of a variety of hydrazine derivative. A new acid-catalysed ring contraction, the conversion of 2-benzoyl-3,4-dihydro-1,2-diazepine (3d) into 1-benzoyl-3-methylpyrazol-2-ine