ABSTRACT
Two new species, Pentacarinus maculosus sp. nov. and Pentacarinus tenebrosus sp. nov., from Burmese amber are described. Alongside the type species P. kachinensis already described, they are easily distinguishable by the tegmina patterns. The diagnosis of the genus Pentacarinus is amended, notably with fusion of Pcu + A1 distad of forking CuA, the fork ScP + R approximately close to basal 1/5 of tegmen, basad of forking CuA, and only one transverse veinlet ir between RP and RA on forewings. Additionally, a key to these three species of Pentacarinus is provided.
ABSTRACT
A new species Niryasaburnia nigrutomia sp. nov. of the planthopper family Achilidae from Burmese amber collected from Hukawng Valley (Tanai) of northern Myanmar, is described, notably based on forewing pattern coloration and metatibiotarsal teeth conformation. A new fossil genus with its type species Sinuovenaxius kachinensis gen. et sp. nov. is also described. The tribe Niryasaburniini trib. nov. is established to include Niryasaburnia Szwedo, 2004, and Sinuovenaxius gen. nov., based on a unique combination of characters, of which the following states are particularly notable: head with compound eyes around half the length of pronotum, late forking of ScP+R and CuA after the fusion of Pcu+A1 on the forewing, apical teeth of metatarsomeres I and II both with subapical platellar sensilla, and a unique hindwing pattern with simple RP and biforked MP, CuA with two terminals only, and with A2 simple, reaching the posterior wing margin. The hindwing venation of this new tribe with RP with only one terminal and both MP and CuA with two terminals is unique in Achilidae.
ABSTRACT
A metal-free photosensitized 1,2-imino-sulfamoylation of olefins by employing a tailor-made sulfamoyl carbamate as the difunctionalization reagent has been established. This protocol exhibits versatility across a broad substrate scope, including aryl and aliphatic alkenes, leading to the synthesis of diverse ß-imino sulfonamides in moderate to good yields. This method is characterized by its metal-free reaction system, mild reaction conditions, excellent regioselectivity, and high atom economy, serving as a promising platform for the preparation of ß-amino sulfonamide-containing molecules, particularly in the context of drug discovery.
ABSTRACT
Photoinduced generation of phosphoranyl radicals offers a versatile strategy to access a variety of synthetically valuable radicals. A long-standing challenge remains in the regulation of phosphoranyl radical to undergo α-scission pathway, although the ß-scission mode has been intensively studied. We herein developed an unprecedented protocol for selective α-scission of the P(OH)R3 radical intermediate under photocatalytic conditions. This efficient P-C bond cleavage via α-scission of the P(OH)R3 radicals has been successfully utilized in the alkylation/fluoroalkylation of alkenes.
ABSTRACT
Development of a new catalytic and straightforward strategy to construct C-N bonds is playing a pivotal role in synthetic chemistry. Here, we report a photocatalysed protocol to access direct C-H amidation of indoles, enabled by a rationally designed tert-butyl alkyl((perfluoropyridin-4-yl)oxy)carbamate. A series of biologically important aminoindoles were prepared under mild conditions with excellent regioselectivity and broad substrate scope.
ABSTRACT
A metal-free photosensitized three-component reaction of oxime esters, alkenes, and DABCO·(SO2)2 was developed. This protocol could accommodate a wide substrate scope, including activated and unactivated alkenes and aryl and aliphatic carboxylic acid oxime esters, delivering a broad range of ß-amino sulfones in moderate to high yields. The insertion of SO2 as a linker moiety allows the manipulation of the functionality in the reaction process, expanding the utility of oxime esters as bifunctional reagents.
