?-Alkyl-?-aminosilanes: Synthesis via Alkylation and Hydrosilylation

Disulfonimide-Catalyzed Asymmetric Synthesis of β3-Amino Esters Directly from N-Boc-Amino Sulfones

“…A 4.5:1 mixture of the two silylated Mannich products N -TBS- 5a and O -TBS- 5a results from this reaction at 0 °C in CDCl 3 . Under these conditions, no obvious equilibration between the two isomers takes place, but after two days at room temperature their ratio will change to >20:1 in CDCl 3 and d 8 -toluene, suggesting intermediate N -TBS- 5a to be thermodynamically favored . A similar product mixture is generated in a 5.7:1 ratio when product 5a was treated with TBSOTf and NEt 3 in CDCl 3 at room temperature.…”

Asymmetric Synthesis of α-Amino Allyl, Benzyl, and Propargyl Silanes by Metalation and Rearrangement

“…The aza-Brook rearrangement ( 1b → 2b ) has been studied almost as long as the oxygen-based original, but the high basicity of nitrogen anion 1b leads to side reactions, reducing its utility. Derivatization of an amine with a Boc group, however, greatly acidifies the nitrogen, providing a driving force favoring 1b , as well as acting as a metalation-directing group. 9a,

2 Metalation/Rearrangement of Benzylamine

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Enantioselective Synthesis of α-Silylamines by Meerwein–Ponndorf–Verley-Type Reduction of α-Silylimines by a Chiral Lithium Amide

“…Introducing silicon into bioactive compounds has attracted considerable interest in medicinal chemistry in view of potentially induced changes in conformations, lipophilicity, bonding property, and electronic nature . One of the major applications for silicon-containing molecules is their use as a carbon isostere, in which, for example, silicon-based amino acids can act as an active tetrahedral intermediate of a protease inhibitor. , From that of point of view, enantioselective synthesis of α-silylamines has recently attracted considerable attention . Although there have been many reports on the synthesis of racemic α-silylamines since the first preparation by Speier and Sommer in 1951, only a few methods for enantioselective synthesis of these compounds are available.…”