Reductive Lithiation of Methyl Substituted Diarylmethylsilanes: Application to Silanediol Peptide Precursors

Abstract

Reductive lithiation of methyl-substituted diarylmethylsilanes using lithium naphthalenide represents a practical method for the preparation of the corresponding silyl lithium reagents. Their addition to chiral sulfinimines affords versatile precursors to silanols and silanediols. The replacement of the currently used diphenylsilane motif by a more labile diarylsilane moiety allows the selective hydrolysis of one or two aryl groups by treatment with TFA.

Bioactive Amino Acids, Peptides and Peptidomimetics Containing Silicon

“…Protodesilylation is Fig. 8.13 Sterically unhindered, water soluble 54, was an ineffective inhibitor of arginase also a classic electrophilic aromatic substitution reaction, promoted by the ability of silicon to stabilize a β-cation (56), and the reactivity of the aromatic ring can be altered by ring substitution [60,61]. Use of diphenylsilyl as a silanediol precursor turned out to be a fortuitous choice because of the importance of phenyl groups in the formation and stabilization of silane anions (see Fig.…”

“…In cases without amides on both sides of the silane, loss of the second phenyl group is slower and more difficult [64]. Triflic acid has been routinely used for this deprotection step, but recently methods employing the much milder trifluoroacetic acid have been enumerated [61].…”

Synthesis and structural study of precursors of novel methylsilanediols by IR and Raman spectroscopies, single-crystal X-ray diffraction and DFT calculations

“…Treatment of this amine freshly obtained with benzyl chloride, acetic anhydrate and formic acid under inert atmosphere, provided several representative amide moiety on the left-hand side of the structure 5a-c in moderate yielded using classical substitution chemistry [20][21][22][23][24].…”

Silanediol versus chlorosilanol: hydrolyses and hydrogen-bonding catalyses with fenchole-based silanes

“…Two synthetic routes are available for syntheses of organosilanediols: If diphenylsilanes are used as building blocks, this route is well suited for syntheses of silanediols with electrophilic functions. In this case, the phenyl groups at the silicon atom are converted by acids (e.g., TFA or TfOH) and following aqueous work-up into silanediols [2,4,7–11]. Another route employs dichlorosilanes, which hydrolyze directly with nucleophiles (e.g., water [12–17] or hydroxide [18–22]) to the corresponding silanediols.…”