A Convergent, Stereoselective Route to Trisubstituted Alkenyl Boronates
作者:Jean Michalland、Samir Z. Zard
DOI:10.1021/acs.orglett.1c03022
日期:2021.10.15
A modular, stereoselectiveroute to trisubstituted (Z)-alkenyl (MIDA)boronates is described, consisting of the radical addition–fragmentation of dithiocarbonates to 2-(MIDA)boronyl-3-(2′-fluoro-pyridyl-6′-oxy)-alkenes. The bulky (MIDA)boronate ensures a highly stereoselective fragmentation that is enhanced by the poor stabilization of the radical adjacent to the tetravalent boron atom. The vinyl boronate
Xanthate-mediated intermolecular alkylation of pyrazines
作者:Qi Huang、Ling Qin、Samir Z. Zard
DOI:10.1016/j.tet.2018.08.040
日期:2018.10
An expedient approach for the intermolecular C-H functionalization of pyrazines and other heteroarenes by the radical chemistry of xanthates is reported. Incorporation of a multitude of functional alkyl groups onto these heteroarenes proceeds in good yield and good to excellent regioselectivity, leading to highly functionalized heteroaromatics.
A Highly Stereoselective, Modular Route to (<i>E</i>)-Vinylsulfones and to (<i>Z</i>)- and (<i>E</i>)-Alkenes
作者:Marie-Gabrielle Braun、Béatrice Quiclet-Sire、Samir Z. Zard
DOI:10.1021/ja207944c
日期:2011.10.12
A recently discovered radical fragmentation of 2-fluoro-6-pyridinoxy derivatives allows a new highlystereoselective and convergent route to (E)-vinylsulfones from allylic alcohols. Reductive desulfonylation or nickel-catalyzed couplings furnish di- and trisubstituted (E)- and (Z)-alkenes.
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.
The carboazidation of chiralallylsilanes has been investigated by varying the nature of the substituents at the silicon center and on the carbon framework. The influence of temperature and the nature of the sulfonyl azide, as well as the stereochemistry of the remote stereogenic center, on the 1,2-diastereocontrol of the process were considered. Good to excellent levels of diastereocontrol were generally