Co(II)-Catalyzed Regioselective Pyridine C–H Coupling with Diazoacetates

Abstract

A Co(II)-catalyzed pyridyl C−H bond carbenoid insertion with α-diazoacetates has been realized. This transformation features a highly regioselective C−C bond formation at the C3-position of pyridines, providing an efficient access to diverse α-aryl-α-pyridylacetates.

Synthesis and Rhodium(II)-Mediated Cascade Cyclopropanation/Rearrangement/Isomerization of Diazo 2,3,5-Trisubstituted Furans: The Construction of Penta-substituted Aromatic Compounds

“…On the other hand, the effect of catalyst loading of CF 3 CO 2 Ag between 5 and 20 mol % was exploited ( 14). Thus, the optimal conditions for the formation of 2aa were obtained as follows: the use of CF 3 CO 2 Ag (20 mol %) as the catalyst and DCE as the solvent at 60 °C.…”

“…5 Hz,3H). 13 C {1H} NMR (125.8 MHz,CDCl 3 ,ppm): δ 197.9,171.3,159.9,149.2,141.2,140.3,136.5,133.1,128.5,128.2,128.0,127.9,127.5,124.0,116.6,113.2,61.6,41.1,19.5,14 375.1591;found, 375.1597. 4.5.3.…”

“…A diazo compound is a sort of important intermediates and have been extensively employed as a carbene source in organic synthesis. Many achievements have been made in the synthesis and application of diazo compounds. − For example, the functionalization of nonactivated C–H bonds, cyclopropanation reaction − (Scheme a), and C­(sp 2 )–H insertion reaction − (Scheme b) has been described in literatures. However, the cyclopropanation on the furan ring via metal carbenoid has rarely been reported .…”

Selective C3–H nitration of 2-sulfanilamidopyridines withtert-butyl nitrite

“…In particular, the halogenation of 2-aminopyridines generally occurs at the C5 position. 2 Methods for C5–H alkylation, 3 sulfonylation, 4 and arylselenation 5 of 2-aminopyridine derivatives have also been reported. On the other hand, selective C3–H functionalization of 2-aminopyridines is rarely reported, despite the good ortho directing ability of amino group.…”

Lewis Acid-Catalyzed Selective Reductive Decarboxylative Pyridylation of N-Hydroxyphthalimide Esters: Synthesis of Congested Pyridine-Substituted Quaternary Carbons

“…Pyridines are essential structural units that exist in a wide range of biologically active molecules, natural products, and functional materials . Functionalization of pyridines with conventional two-electron process, including nucleophilic aromatic substitution (S N Ar), and transition-metal catalyzed C–H activation, has been broadly investigated. However, sensitive organometallic reagents or transition-metal catalysts are always required in these processes.…”