A Convenient Metal-Free Reagent for the Generation and Capture of Trifluoromethanethiol
摘要:
0-Octadecyl-S-trifluorothiolcarbonate is a cheap and storable crystalline source of trifluoromethanethiol that can be prepared in two steps on a multigram scale from trifluoroacetic anhydride and sodium 0-octadecyl-dithiocarbonate (xanthate). It reacts directly with gramines or with alpha-bromoketones and -esters in the presence of KF and pyrrolidine to give the corresponding trifluoromethyl sulfides in generally high yield.
A Convenient Metal-Free Reagent for the Generation and Capture of Trifluoromethanethiol
摘要:
0-Octadecyl-S-trifluorothiolcarbonate is a cheap and storable crystalline source of trifluoromethanethiol that can be prepared in two steps on a multigram scale from trifluoroacetic anhydride and sodium 0-octadecyl-dithiocarbonate (xanthate). It reacts directly with gramines or with alpha-bromoketones and -esters in the presence of KF and pyrrolidine to give the corresponding trifluoromethyl sulfides in generally high yield.
A Convergent Synthesis of Enantiopure Open-Chain, Cyclic, and Fluorinated α-Amino Acids
作者:Shi-Guang Li、Fernando Portela-Cubillo、Samir Z. Zard
DOI:10.1021/acs.orglett.6b00656
日期:2016.4.15
A radical based synthesis of a broad variety of protected enantiopure α-amino acids, including fluorinatedderivatives, is described. The radicaladdition furnishes naturally latent mercapto-α-amino acids ideally equipped for native chemical ligation.
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.
Radical Instability in Aid of Efficiency: A Powerful Route to Highly Functional MIDA Boronates
作者:Béatrice Quiclet-Sire、Samir Z. Zard
DOI:10.1021/jacs.5b03893
日期:2015.6.3
The inability of the sp(3) boron in MIDA boronates to stabilize an adjacent radical makes possible the efficient addition of a wide array Of xanthates to vinyl MIDA boronate, leading to highly functionalized and diverse aliphatic organoboron structures. The lack of radical Stabilization also allows the exchange Of the Xanthate in the adducts with a bromine. In one case, the bromine was substituted to generate a cyclopropyl MIDA derivative.
Carbon Radical Attack on a Pyrimidine Nitrogen. An Unusual Entry into Polycyclic Aminopyrimidones
作者:Ling Qin、Zhibo Liu、Samir Z. Zard
DOI:10.1021/ol501104h
日期:2014.6.6
Unprecedented examples of a synthetically useful radical ring closure onto a pyrimidine nitrogen leading to novel, highly functionalized bi- and tricyclic pyrimidone structures are reported. An unexpected hydrogen atom translocation prior to the cyclization step was observed in some cases.