Synthesis of Acylsilanes via Nickel-Catalyzed Reactions of α-Hydroxyallylsilanes
摘要:
The redox isomerization processes and tandem isomerization-aldolization reactions, mediated by nickel catalysts, offer new versatile entries to acylsilanes. For the second reaction, high diastereoselectivities, up to 98:2, have been obtained with bulky substituents on silicon.
We have successfully developed the asymmetric hydrogenation of β‐silyl‐α,β‐unsaturatedesters to prepare chiral 3‐substituted‐3‐silylpropionic esterproducts catalyzed by rhodium/bisphosphine‐thiourea (ZhaoPhos) with excellent results (up to 97% yield, >99% ee, 1500 TON). Moreover, our hydrogenation products can be efficiently converted to other important organic molecules, such as chiral ethyl (R
Properties of the methyllithium species Li4(CH3)3+, Li4(CH3)2+, Li4CH3+, Li2CH3+, LiCH3+, and Li2(CH32 have been probed by the application of an ab initio computational procedure. These lithiumcluster species are the methyl analog of the products observed experimentally to result from the fragmentation of ethyllithium and t-butyllithium. The procudure was used to determine the optimum geometry for
[1,2]-Brook rearrangement can dearomatize aromatic N-heterocycles! Through a one-pot four-step process that includes lithiation, nucleophilic addition, Brook rearrangement, and dearomatization reaction, we enable the formation of non-aromatic N-heterocycles with functional capabilities starting from readily available precursors. Subsequent functionalization reactions provide access to a diverse compound