A library of chiral supramolecular ligands, named BenzaPhos, of straightforward preparation (two steps from commercially or readily available starting materials) and modular structure, was designed and synthesized. The ligands were screened in the search for new rhodium catalysts for the enantioselective hydrogenation of several benchmark and industrially relevant substrates. Once a series of hits
A regioselective and stereoselective difluoromethylation of enamides with bench-stable and easily accessible difluoromethyltriphenylphosphonium bromide is described. A broad array of synthetically important and geometrically defined β-difluoromethylated enamides bearing various functional groups are obtained with up to 91% yield.
in four steps. These newligands were screened in the rhodium‐catalyzed enantioselective hydrogenation of prochiral dehydroamino esters and enamides. Several members of the library showed excellent enantioselectivity with methyl 2‐acetamido acrylate (6 ligands gave >97 % ee), methyl (Z)‐2‐acetamido cinnamate (6 ligands gave >94 % ee), and N‐(1‐phenylvinyl)acetamide (9 ligands gave >95 % ee), whilst
C(sp<sup>2</sup>)–H Trifluoromethylation of enamides using TMSCF<sub>3</sub>: access to trifluoromethylated isoindolinones, isoquinolinones, 2-pyridinones and other heterocycles
作者:Vinayak Krishnamurti、Socrates B. Munoz、Xanath Ispizua-Rodriguez、Jeffrey Vickerman、Thomas Mathew、G. K. Surya Prakash
DOI:10.1039/c8cc04907f
日期:——
A method for the direct C(sp2)–H trifluoromethylation of enamides, including biologically relevant isoindolinones, isoquinolinones and 2-pyridinones using TMSCF3 under oxidative conditions is presented. The protocol is convenient, operationally simple and exhibits high tolerance across a multitude of relevant handles and functional groups.