摘要:
An optically active 2,3-bis(dialkylphosphino)pyrazine derivative represented by formula (1) is disclosed. The pyrazine derivative is preferably a quinoxaline derivative represented by formula (2). In formula (1) and (2), R1 is preferably a t-butyl or adamantyl group, and R2 is preferably a methyl group. wherein R1 is a substitutable straight chain or branched alkyl group having 2 to 10 carbon atoms; R2 is a substitutable straight chain or branched alkyl group having fewer carbon atoms than R1; and R3 and R4, which may be the same or different, are each a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, or R3 and R4 are taken together to form a saturated or unsaturated ring. wherein R1 and R2 are as defined above; and R5 is a monovalent substituent.
摘要:
An optically active 2,3-bis(dialkylphosphino)pyrazine derivative represented by formula (1) is disclosed. The pyrazine derivative is preferably a quinoxaline derivative represented by formula (2). In formula (1) and (2), R1 is preferably a t-butyl or adamantyl group, and R2 is preferably a methyl group. wherein R1 is a substituted or unsubstituted, straight chain or branched alkyl group having 2 to 10 carbon atoms; R2 is a substituted or unsubstituted, straight chain or branched alkyl group having fewer carbon atoms than R1; and R3 and R4, which may be the same or different, are each a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, or R3 and R4 are taken together to form a saturated or unsaturated ring. wherein R1 and R2 are as defined above; and R5 is a monovalent substituent.
摘要翻译:公开了由式(1)表示的光学活性2,3-双(二烷基膦基)吡嗪衍生物。 吡嗪衍生物优选为式(2)表示的喹喔啉衍生物。 式(1)和(2)中,R 1优选为叔丁基或金刚烷基,R 2优选为甲基。 其中R 1是具有2至10个碳原子的取代或未取代的直链或支链烷基; R 2是具有比R 1更少的碳原子的取代或未取代的直链或支链烷基; R 3和R 4可以相同或不同,分别为氢原子或具有1-6个碳原子的烷基,或R“ 3和R 4一起形成饱和或不饱和的环。 其中R 1和R 2如上定义; R 5是一价取代基。
摘要:
An optically-active bis(alkynylphosphino)ethane-borane derivative represented by formula (1): wherein R1 and R2, which may be the same or different, each represent an alkyl group, a phenyl group, an alkylsilyl group or a hydrogen atom; R3 represents a branched alkyl group, an alicyclic hydrocarbon group or an aromatic hydrocarbon group; and the asterisk * indicates an optically-active site. The derivative (1) is prepared by bromination of, e.g., an (S)-t-butylmethylphosphine-borane, reaction with an alkynyl lithium, deprotonation, followed by oxidative coupling. Deprotection of the derivative (1) by deboranation gives an optically-active bis(alkynylphosphino)ethane derivative useful as a ligand providing an asymmetric catalyst for catalytic asymmetric synthesis. The asymmetric catalyst having the ligand exhibits high selectivity and catalyst activity.
摘要:
Disclosed is a process of preparing an optically active β-hydroxycarboxylic acid derivative comprising asymmetrically hydrogenating a β-keto compound in the presence of a catalyst comprising a transition metal complex compound having a 2,3-bis(dialkylphosphino)pyrazine derivative as a ligand. The pyrazine derivative is preferably a quinoxaline derivative, and the transition metal is preferably ruthenium. Preferred examples of the quinoxaline derivative are (S,S)-2,3-bis(tert-butylmethylphosphino)quinoxaline, (R,R)-bis(tert-butylmethylphosphino)quinoxaline, (S,S)-bis(tert-adamantylmethylphosphino)quinoxaline, and (R,R)-bis(adamantylmethylphosphino)quinoxaline.
摘要:
An optically-active bis(alkynylphosphino)ethane-borane derivative represented by formula (1): wherein R1 and R2, which may be the same or different, each represent an alkyl group, a phenyl group, an alkylsilyl group or a hydrogen atom; R3 represents a branched alkyl group, an alicyclic hydrocarbon group or an aromatic hydrocarbon group; and the asterisk * indicates an optically-active site. The derivative (1) is prepared by bromination of, e.g., an (S)-t-butylmethylphosphine-borane, reaction with an alkynyl lithium, deprotonation, followed by oxidative coupling. Deprotection of the derivative (1) by deboranation gives an optically-active bis(alkynylphosphino)ethane derivative useful as a ligand providing an asymmetric catalyst for catalytic asymmetric synthesis. The asymmetric catalyst having the ligand exhibits high selectivity and catalyst activity.
摘要:
Disclosed is a process of preparing an optically active allyl compound, e.g., as represented by formula (III): comprising asymmetrically coupling an allyl compound with an organic nucleophilic compound in the presence of a catalyst. The catalyst is preferably a transition metal complex compound having a phosphine ligand. The phosphine ligand is preferably a 2,3-bis(dialkylphosphino)pyrazine derivative. The pyrazine derivative is preferably a quinoxaline derivative. The transition metal is preferably palladium.
摘要:
In a ceramic capacitor, first and second electrode terminals each include a bonded-to-substrate portion, a first bonded-to-electrode portion bonded to a first edge of one of first and second external electrodes, a second bonded-to-electrode portion bonded to a second edge of the one of first and second external electrodes and disposed at a distance from the first bonded-to-electrode portion in the first directions, and a connecting portion connecting the first and second bonded-to-electrode portions and the bonded-to-substrate portion. W1/W0 is about 0.3 or more, and h/L is about 0.1 or more.
摘要:
Provided is a roller bearing device, which is suitable for preventing misdetection of a rotation sensor when a moment load is applied. A thin motor 100 includes a cross roller bearing 14 having an inner ring 14a and an outer ring 14b, a stator 22 supported by the inner ring 14a, a rotor 12 supported by the outer ring 14b, a motor unit 16 that applies rotation torque to the rotor 12, and a resolver 30 that detects a rotation angle position of the rotor 12. The resolver 30, the cross roller bearing 14, and the motor unit 16 are arranged in the recited order from the radially inner side on a radially identical plane.
摘要:
A triaxial acceleration sensor which has a structure including a cover joined to a substrate including a mechanically operable functional unit to be sealed, is adapted in such a way that the joined state can be reliably obtained so as to not interfere with a displacement of the functional unit. A sealing frame is made of a heated polyimide on a periphery of an upper main surface of a substrate provided with a functional unit, and a sealing layer made of a polyimide is formed over an entire lower main surface of a cover. For integrating the substrate and the cover so as to seal the functional unit, the sealing frame and the sealing layer are joined to each other by heating and pressurizing the sealing frame and the sealing layer at a temperature that is about 50° C. to about 150° C. higher than a glass transition temperature of the polyimide while bringing the sealing frame and the sealing layer into contact with each other. In this case, a recess is formed in the vicinity of a portion of the sealing layer to be brought into contact with the sealing frame so that a bump, generated from the sealing layer which is deformed in the joining step, is prevented from protruding toward the functional unit.