Chemoselective Reduction: Xanthates as Traceless Precursors of Polyfunctionalized α,α-Dichloroketones
摘要:
The use of BEt3 center dot H2O has allowed the chemoselective reductive dexanthylation in the presence of the very fragile alpha,alpha-dichloroketone motif. This has solved a major hurdle in our approach to this important, but hitherto grossly understudied, family of compounds and opened access to a number of very useful synthetic transformations.
A Direct Approach to Orthogonally Protected α-Amino Aldehydes
作者:Richard Lamb、Vincent L. Revil-Baudard、Samir Z. Zard
DOI:10.1021/acs.orglett.9b02237
日期:2019.8.16
O-Neopentyl-xanthate 19 bearing a masked α-amino aldehyde, with the two functional groups orthogonallyprotected, reacts cleanly with many functional alkenes. The radical addition–transfer furnishes densely functionalized adducts that can be further transformed into an array of amino-substituted carbocycles and heteroaromatics. They are also easily converted into imidazolones.
Radical Fragment Coupling Route to Geminal Bis(boronates)
作者:Qi Huang、Samir Z. Zard
DOI:10.1021/acs.orglett.8b02235
日期:2018.9.7
atom abstraction and delivers a vast array of highly functional geminal bis(boronates). The ability to assemble geminal bis(boronates) bearing polar functional groups not readily obtained through existing methods is particularly noteworthy. This approach also opens up access to geminal bis(boronyl) cyclopropanes and geminal bis(boronyl) tetrahydroquinolines.
Herein we present a simple catalytic approach to the synthesis of organosilylfunctional polybutadienes. The use of highly active Rh(I) catalysts enabled high conversions of a wide range of organofunctional silicon-based modifiers, which permitted obtaining a library of new functional polymers equipped with attractive silicon-based functional groups. The use of real-time FT-IR spectroscopy allowed us
Geminal mercapto trialkyl- and trialkoxy-silanes undergo an efficient radical chain rearrangement, whereby the silyl group migrates from carbon to sulfur; the starting materials are readily obtained by exploiting the peroxide initiated radical addition of dithiocarbonates (xanthates) to trialkyl- or trialkoxy-vinylsilanes.
A direct, versatile route to functionalized trialkoxysilanes
作者:Béatrice Quiclet-Sire、Yuuki Yanagisawa、Samir Z. Zard
DOI:10.1039/c3cc48570f
日期:——
The peroxide initiated radical addition of dithiocarbonates (xanthates) to trialkoxy vinylsilanes leads to functionalized trialkoxysilanes. Prior addition of the dithiocarbonates to an alkene before reaction with the vinylsilane can be used to increase the complexity of the final product.