文摘
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The treatment of chiral sulfinimines with (methyldiphenylsilyl)lithium gives -(methyldiphenylsilyl)sulfinamides with excellent diastereoselectivity, and in good yield. The presence of -protons on theimines is also well tolerated. The sulfinamide auxiliary is easily removed via treatment with methanolicHCl and the resulting amine extended into peptide chains accordingly. The diphenylsilyl moiety is aresilient protecting group for the corresponding silanediol, which can be unmasked via treatment withTfOH, followed by aqueous hydrolysis. The crude silanediol may be isolated and purified as itscorresponding bis-TMS siloxane via protection with TMSCl, and converted back to the desired silanediolvia hydrolysis with aqueous KOH. Efforts to apply this approach to biologically relevant silanediol peptidemimics, with a view to protease inhibition, are described.
