Abstract: A light-emitting element with high emission efficiency is provided. In addition, a light-emitting element having a low driving voltage is provided. Furthermore, a novel compound which can be used for a transport layer, a host material, or a light-emitting material of a light-emitting element is provided. A novel compound including a benzothienopyrimidine skeleton is provided. Furthermore, a light-emitting element including a pair of electrodes and an EL layer sandwiched between the pair of electrodes is provided. The EL layer contains a substance including the benzothienopyrimidine skeleton.

Abstract: Provided is a 5,6-diaryl-2-pyrazyl triflate, its synthetic method, and a method for synthesizing an organometallic complex having a triarylpyrazine ligand from the 5,6-diaryl-2-pyrazyl triflate. The triflate is readily obtained from the corresponding 5,6-diarylpyrazin-2-ol, and the palladium-catalyzed coupling of the 5,6-diaryl-2-pyrazyl triflate with an arylboronic acid derivative leads to a high yield of a triarylpyrazine derivative having high purity. The use of the triarylpyrazine derivative in the reaction with a metal compound such as a metal chloride results in an ortho-metallated organometallic complex with high purity. The high purity of the organometallic complex contributes to the extremely high durability of a light-emitting element.

Abstract: As a novel substance having a novel skeleton, an organometallic complex with high emission efficiency which achieves improved color purity by a reduction of half width of an emission spectrum is provided. One embodiment of the present invention is an organometallic complex in which a ?-diketone and a six-membered heteroaromatic ring including two or more nitrogen atoms inclusive of a nitrogen atom that is a coordinating atom are ligands. In General Formula (G1), X represents a substituted or unsubstituted six-membered heteroaromatic ring including two or more nitrogen atoms inclusive of a nitrogen atom that is a coordinating atom. Further, R1 to R4 each represent a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

Abstract: As a novel substance having a novel skeleton, an organometallic complex with high emission efficiency which achieves improved color purity by a reduction of half width of an emission spectrum is provided. One embodiment of the present invention is an organometallic complex in which a ?-diketone and a six-membered heteroaromatic ring including two or more nitrogen atoms inclusive of a nitrogen atom that is a coordinating atom are ligands. In General Formula (G1), X represents a substituted or unsubstituted six-membered heteroaromatic ring including two or more nitrogen atoms inclusive of a nitrogen atom that is a coordinating atom. Further, R1 to R4 each represent a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

Abstract: Provided is a 5,6-diaryl-2-pyrazyl triflate, its synthetic method, and a method for synthesizing an organometallic complex having a triarylpyrazine ligand from the 5,6-diaryl-2-pyrazyl triflate. The triflate is readily obtained from the corresponding 5,6-diarylpyrazin-2-ol, and the palladium-catalyzed coupling of the 5,6-diaryl-2-pyrazyl triflate with an arylboronic acid derivative leads to a high yield of a triarylpyrazine derivative having high purity. The use of the triarylpyrazine derivative in the reaction with a metal compound such as a metal chloride results in an ortho-metallated organometallic complex with high purity. The high purity of the organometallic complex contributes to the extremely high durability of a light-emitting element.

Abstract: An organometallic iridium complex has high emission efficiency and a long lifetime. The iridium complex includes the structure represented by Formula (G1). In the formula, Ar represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms. R1 to R6 independently represent any one of hydrogen and a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and one of R2 and R6 represents the alkyl group. X represents a carbon atom or a nitrogen atom, and when X represents a carbon atom, hydrogen or an alkyl group having 1 to 6 carbon atoms is bonded to the carbon atom. A dihedral angle between a ring bonded to R1 and a phenyl group bonded to R2 to R6 is 30° or more and 90° or less. An interior angle of the pyridine/pyrimidine ring facing R1 is within a range of 118° to 122°.

Abstract: Provided as a novel substance is a long-lifetime organometallic iridium complex emitting yellow light with high emission efficiency. The organometallic iridium complex is represented by General Formula (G1) and has a structure in which a phenyl group whose 2-position and 6-position are each substituted by an alkyl group is bonded to the 4-position of pyrimidine. In General Formula (G1), R1 and R2 each independently represent a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

Abstract: A light-emitting element having high emission efficiency is provided. A light-emitting element having a low driving voltage is provided. A novel compound which can be used for a transport layer or as a host material or a light-emitting material of a light-emitting element is provided. A novel compound with a benzofuropyrimidine skeleton is provided. Also provided is a light-emitting element which includes the compound with the benzofuropyrimidine skeleton between a pair of electrodes.

Abstract: As a novel substance having a novel skeleton, an organometallic complex having high emission efficiency and improved color purity is provided. The color purity is improved by reducing the half width of an emission spectrum. The organometallic complex is represented by General Formula (G1). In General Formula (G1), at least one of R1 to R4 represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and the others each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. Note that the case where all of R1 to R4 represent alkyl groups each having 1 carbon atom is excluded. Further, R5 to R9 each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

Abstract: A light-emitting element with high heat resistance and high emission efficiency is provided. A novel heterocyclic compound that can be used in such a light-emitting element is provided. One embodiment of the present invention is a light-emitting element which includes, between a pair of electrodes, a layer containing a first organic compound, a second organic compound, and a light-emitting substance; the first organic compound includes one pyrimidine ring and one ring with a hole-transport skeleton; the second organic compound is an aromatic amine; and the light-emitting substance converts triplet excitation energy into light. A combination of the first organic compound, which includes the one pyrimidine ring and the one ring with the hole-transport skeleton, and the second organic compound, which is the aromatic amine, forms an exciplex.