Alternating Radical Stabilities: A Convergent Route to Terminal and Internal Boronates
作者:Qi Huang、Jean Michalland、Samir Z. Zard
DOI:10.1002/anie.201906497
日期:2019.11.18
on the boron atom, thus stabilizing or not stabilizing the corresponding adjacent radical, it is possible to control the behavior of α-boronyl xanthates and construct a large variety of terminal or internal boronates in a modular fashion. The remarkable tolerance of polar groups and the ability to introduce quaternary centers are particularly noteworthy features of this process.
Radicals from Aldehydes: A Convergent Access to Dienes and δ-Lactones
作者:Samir Zard、Sharanjeet Bagal、Lucie Tournier
DOI:10.1055/s-2006-941582
日期:2006.6
A convenient method for the generation of O,S-acetal xanthates from aldehydes has been developed. The corresponding nucleophilic radicals undergo facile addition to unactivated olefins and the resulting adducts can be further elaborated to generate dienes and unsaturated δ-lactones.
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
Tri- and Tetrasubstituted Functionalized Vinyl Sulfides by Radical Allylation
作者:Laurent Debien、Marie-Gabrielle Braun、Béatrice Quiclet-Sire、Samir Z. Zard
DOI:10.1021/ol403103u
日期:2013.12.20
2-Fluoropyridinyl-6-oxy- precursors derived from phenyl vinyl sulfide react with radicals generated from xanthates via an addition–elimination process to furnish the corresponding vinyl sulfides in good yields. This convergent method is operationally simple and enables a straightforward synthesis of the difficult to access tetrasubstituted vinyl sulfides. Vinyl sulfides were used as more robust enol ether surrogates
From a Remarkable Manifestation of Polar Effects in a Radical Fragmentation to the Convergent Synthesis of Highly Functionalized Ketones
作者:Laurent Debien、Samir Z. Zard
DOI:10.1021/ja400831w
日期:2013.3.13
A new radical addition/C-C bond fragmentation process is reported. Vinyl carbinols derived from 2-methyl-2-phenylpropanal react with radicals generated from xanthates to give the corresponding ketones. The radical cleavage reaction proceeds under mild conditions, in good to high yield, and in the presence of the unprotected carbinol. Highly functionalized 1,5-diketones and pyridines are readily available