Blue light-promoted N–H insertion of amides, isatins, sulfonamides and imides into aryldiazoacetates: Synthesis of unnatural α-aryl amino acid derivatives
作者:Celso Y. Okada、Caio Y. dos Santos、Igor D. Jurberg
DOI:10.1016/j.tet.2020.131316
日期:2020.12
A photochemical protocol using blue light allows the N–H insertion of amides, isatins, sulfonamides and imides into aryldiazoacetates to afford the corresponding α-amino esters. This method is experimentally simple, inexpensive and tolerates numerous functional groups, thus allowing the straightforward preparation of a variety of α-aryl amino acid derivatives in good yields.
Guide to enantioselective dirhodium(II)-catalyzed cyclopropanation with aryldiazoacetates
作者:Kathryn M. Chepiga、Changming Qin、Joshua S. Alford、Spandan Chennamadhavuni、Timothy M. Gregg、Jeremy P. Olson、Huw M.L. Davies
DOI:10.1016/j.tet.2013.04.075
日期:2013.7
Catalytic enantioselective methods for the generation of cyclopropanes have been of long standing pharmaceutical interest. Chiraldirhodium(II) catalysts prove to be an effective means for the generation of diverse cyclopropane libraries. Rh2(R-DOSP)4 is generally the most effective catalyst for asymmetric intermolecular cyclopropanation of methyl aryldiazoacetates with styrene. Rh2(S-PTAD)4 provides
用于生成环丙烷的催化对映选择性方法长期以来一直是制药业的兴趣所在。手性二铑 (II) 催化剂被证明是生成各种环丙烷库的有效手段。Rh 2 ( R -DOSP) 4通常是重氮乙酸甲酯与苯乙烯的不对称分子间环丙烷化反应最有效的催化剂。Rh 2 ( S -PTAD) 4提供高水平的邻位取代芳基重氮乙酸酯的对映体诱导。不太成熟的 Rh 2 ( R -BNP) 4对 Rh 2 ( R-DOSP) 4和 Rh 2 ( S -PTAD) 4在催化 3-甲氧基取代的重氮基乙酸芳基酯的高度对映选择性环丙烷化反应中。苯乙烯的取代对环丙烷化的不对称诱导仅具有中等影响。
Copper on charcoal: Cu<sup>0</sup> nanoparticle catalysed aerobic oxidation of α-diazo esters
By using a charcoal supported nano Cu0 catalyst (Cu/C), a highly efficient oxidation of α-diazo esters to α-ketoesters with molecular oxygen as the sole oxidant has been developed. In the presence of the Cu/C catalyst, 2-aryl-α-diazo esters with both electron-donating and electron-withdrawing groups can be oxidized to the corresponding α-ketoesters efficiently. Furthermore, this Cu/C catalyst can catalyse
An asymmetric carbenoidinsertion into S-H bonds catalyzed by copper-chiral spiro bisoxazoline complexes has been developed, in which a series of alpha-mercaptoesters were produced in high yields with moderate to good enantioselectivities (up to 85% ee); this result represents the best enantioselectivity in the catalytic asymmetric carbenoid S-H bond insertion reaction.
Copper-Catalyzed B–H Bond Insertion Reaction: A Highly Efficient and Enantioselective C–B Bond-Forming Reaction with Amine–Borane and Phosphine–Borane Adducts
A copper-catalyzed B-H bond insertion reaction with amine- and phosphine-borane adducts was realized with high yield and enantioselectivity under mild reaction conditions. The B-H bond insertion reaction provides a new C-B bond-forming methodology and an efficient approach to chiral organoboron compounds.