Patents by Inventor Tsuneo Imamoto

Tsuneo Imamoto has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20220204537
    Abstract: There is provided a novel optically active bisphosphinomethane useful as a ligand for an asymmetric catalyst, excellent in oxidation resistance in air, and easy in handling. There is also provided a transition metal complex using the optically active bisphosphinoraethane having excellent asymmetric catalytic ability as a ligand. The optically active bisphosphinomethane is represented by the general formula (1), and the transition metal complex has the optically active bisphosphinomethane as a ligand. (In the formula, R1 represents an adamantyl group; R2 represents a branched alkyl group having 3 or more carbon atoms; and * represents an asymmetric center on a phosphorus atom.
    Type: Application
    Filed: June 9, 2020
    Publication date: June 30, 2022
    Applicant: NIPPON CHEMICAL INDUSTRIAL CO., LTD.
    Inventors: Tsuneo Imamoto, Ken Tamura, Natsuhiro Sano
  • Patent number: 11180516
    Abstract: The phosphine transition metal complex of the present invention is represented by formula (1). Preferably, R1 and R6 are identical groups, R2 and R7 are identical groups, R3 and R8 are identical groups, R4 and R9 are identical groups, R5 and R10 are identical groups, and n and y are identical numbers. The phosphine transition metal complex is suitably obtained by reacting a phosphine derivative represented by formula (2) and a phosphine derivative represented by formula (3) with a salt of a transition metal of gold, copper or silver. See the description for the meanings of the symbols in each formula.
    Type: Grant
    Filed: September 26, 2019
    Date of Patent: November 23, 2021
    Assignee: NIPPON CHEMICAL INDUSTRIAL CO., LTD.
    Inventors: Kazuhiro Nakatsui, Chiaki Ono, Nobuhiko Oohara, Tsuneo Imamoto, Hiroaki Konishi, Hikaru Abutani
  • Publication number: 20210253612
    Abstract: The phosphine transition metal complex of the present invention is represented by formula (1). Preferably, R1 and R6 are identical groups, R2 and R7 are identical groups, R3 and R8 are identical groups, R4 and R9 are identical groups, R5 and R10 are identical groups, and n and y are identical numbers. The phosphine transition metal complex is suitably obtained by reacting a phosphine derivative represented by formula (2) and a phosphine derivative represented by formula (3) with a salt of a transition metal of gold, copper or silver. See the description for the meanings of the symbols in each formula.
    Type: Application
    Filed: September 26, 2019
    Publication date: August 19, 2021
    Applicant: Nippon Chemical Industrial Co., Ltd.
    Inventors: Kazuhiro Nakatsui, Chiaki Ono, Nobuhiko Oohara, Tsuneo Imamoto, Hiroaki Konishi, Hikaru Abutani
  • Patent number: 11084835
    Abstract: Provided is a 2,3-bisphosphinopyrazine derivative represented by the following general formula (1), wherein R1, R2, R3, and R4 represent an optionally substituted straight-chain or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted cycloalkyl group, an optionally substituted adamantyl group, or an optionally substituted phenyl group, R5 represents an optionally substituted alkyl group having 1 to 10 carbon atoms or an optionally substituted phenyl group, each R5 may be the same group or a different group, R6 represents a monovalent substituent, n denotes an integer of 0 to 2.
    Type: Grant
    Filed: March 1, 2019
    Date of Patent: August 10, 2021
    Assignees: NIPPON CHEMICAL INDUSTRIAL CO., LTD., NATIONAL UNIVERSITY CORPORATION HOKKAIDO UNIVERSITY
    Inventors: Hajime Ito, Hiroaki Iwamoto, Tsuneo Imamoto, Ken Tamura, Natsuhiro Sano
  • Patent number: 11053265
    Abstract: An optically active 2,3-bisphosphinopyrazine derivative represented by the following general formula (1): wherein R1 represents a group selected from a branched alkyl group having 3 or more carbon atoms, an adamantyl group, an optionally substituted cycloalkyl group, and an optionally substituted aryl group; R2 represents a group selected from a branched alkyl group having 3 or more carbon atoms, an adamantyl group, and an optionally substituted cycloalkyl group, provided that when R1 is a tert-butyl group, R1 and R2 are not the same; R3 represents a monovalent substituent; n represents an integer of 0 to 4; and * represents an asymmetric center on a phosphorus atom.
    Type: Grant
    Filed: September 28, 2018
    Date of Patent: July 6, 2021
    Assignees: NIPPON CHEMICAL INDUSTRIAL CO., LTD., NATIONAL UNIVERSITY CORPORATION HOKKAIDO UNIVERSITY
    Inventors: Hajime Ito, Hiroaki Iwamoto, Tsuneo Imamoto, Ken Tamura
  • Patent number: 11021500
    Abstract: There is provided a method for producing a 2,3-bisphosphinopyrazine derivative, the method comprising a first step of adding a base to a liquid comprising: 2,3-dihalogenopyrazine represented by the following general formula (1); a hydrogen-phosphine borane compound represented by the following general formula (2); and a deboranating agent, and allowing the resultant to react to thereby obtain the 2,3-bisphosphinopyrazine derivative represented by the following general formula (3). According to the present invention, a method for producing the industrially advantageous 2,3-bisphosphinopyrazine derivative can be provided.
    Type: Grant
    Filed: July 24, 2018
    Date of Patent: June 1, 2021
    Assignee: NIPPON CHEMICAL INDUSTRIAL CO., LTD.
    Inventor: Tsuneo Imamoto
  • Publication number: 20210047351
    Abstract: Provided is a 2,3-bisphosphinopyrazine derivative represented by the following general formula (1), wherein R1, R2, R3, and R4 represent an optionally substituted straight-chain or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted cycloalkyl group, an optionally substituted adamantyl group, or an optionally substituted phenyl group, R5 represents an optionally substituted alkyl group having 1 to 10 carbon atoms or an optionally substituted phenyl group, each R5 may be the same group or a different group, R6 represents a monovalent substituent, n denotes an integer of 0 to
    Type: Application
    Filed: March 1, 2019
    Publication date: February 18, 2021
    Applicants: Nippon Chemical Industrial Co., Ltd., NATIONAL UNIVERSITY CORPORATION HOKKAIDO UNIVERSITY
    Inventors: Hajime Ito, Hiroaki Iwamoto, Tsuneo Imamoto, Ken Tamura, Natsuhiro Sano
  • Publication number: 20200377536
    Abstract: An optically active 2,3-bisphosphinopyrazine derivative represented by the following general formula (1): wherein R1 represents a group selected from a branched alkyl group having 3 or more carbon atoms, an adamantyl group, an optionally substituted cycloalkyl group, and an optionally substituted aryl group; R2 represents a group selected from a branched alkyl group having 3 or more carbon atoms, an adamantyl group, and an optionally substituted cycloalkyl group, provided that when R1 is a tert-butyl group, R1 and R2 are not the same; R3 represents a monovalent substituent; n represents an integer of 0 to 4; and * represents an asymmetric center on a phosphorus atom.
    Type: Application
    Filed: September 28, 2018
    Publication date: December 3, 2020
    Applicants: Nippon Chemical Industrial Co., Ltd., NATIONAL UNIVERSITY CORPORATION HOKKAIDO UNIVERSITY
    Inventors: Hajime Ito, Hiroaki Iwamoto, Tsuneo Imamoto, Ken Tamura
  • Publication number: 20200247833
    Abstract: There is provided a method for producing a 2,3-bisphosphinopyrazine derivative, the method comprising a first step of adding a base to a liquid comprising: 2,3-dihalogenopyrazine represented by the following general formula (1); a hydrogen-phosphine borane compound represented by the following general formula (2); and a deboranating agent, and allowing the resultant to react to thereby obtain the 2,3-bisphosphinopyrazine derivative represented by the following general formula (3). According to the present invention, a method for producing the industrially advantageous 2,3-bisphosphinopyrazine derivative can be provided.
    Type: Application
    Filed: July 24, 2018
    Publication date: August 6, 2020
    Applicant: Nippon Chemical Industrial Co., Ltd.
    Inventor: Tsuneo Imamoto
  • Patent number: 9029571
    Abstract: Provided are a novel 1,2-bis(dialkylphosphino)-4,5-(methylenedioxy)benzene derivative that forms a metal complex having particularly high asymmetry induction capacity and catalytic activity on ?-dehydroamino acids, a method for manufacturing the same, a metal complex having this 1,2-bis(dialkylphosphino)-4,5-(methylenedioxy)benzene derivative as a ligand, and an asymmetric hydrogenation method using this metal complex. A 1,2-bis(dialkylphosphino)-4,5-(methylenedioxy)benzene derivative represented by general formula (1). (In the formula, R1 and R2 represent an alkyl group having 1-10 carbon atoms, and R1 and R2 have different numbers of carbon atoms.
    Type: Grant
    Filed: June 21, 2012
    Date of Patent: May 12, 2015
    Assignee: Nippon Chemical Industrial Co., Ltd.
    Inventors: Zhenfeng Zhang, Tsuneo Imamoto, Ken Tamura
  • Patent number: 8957233
    Abstract: An industrially advantageous method for producing an optically active 1,2-bis(dialkylphosphino)benzene derivative of the present invention is provided. The method is characterized in that a phosphine-borane compound represented by the following general formula (1) is subjected to a deboronation reaction, followed by lithiation, then the reaction product is subjected to reaction with an alkyldihalogenophosphine represented by RaPX?2, and thereafter the reaction product is subjected to reaction with a Grignard reagent represented by RbMgX? to produce an optically active 1,2-bis(dialkylphosphino)benzene derivative (A). R1 and R2 respectively represent an alkyl group having 1 to 8 carbon atoms, and the number of carbon atoms is different between R1 and R2. Ra is either R1 or R2 and Rb is the other of R1 and R2. X, X?, and X? each represent a halogen atom.
    Type: Grant
    Filed: July 3, 2011
    Date of Patent: February 17, 2015
    Assignee: Nippon Chemical Industrial Co., Ltd.
    Inventors: Ken Tamura, Masashi Sugiya, Tsuneo Imamoto
  • Publication number: 20140213800
    Abstract: Provided are a novel 1,2-bis(dialkylphosphino)-4,5-(methylenedioxy)benzene derivative that forms a metal complex having particularly high asymmetry induction capacity and catalytic activity on ?-dehydroamino acids, a method for manufacturing the same, a metal complex having this 1,2-bis(dialkylphosphino)-4,5-(methylenedioxy)benzene derivative as a ligand, and an asymmetric hydrogenation method using this metal complex. A 1,2-bis(dialkylphosphino)-4,5-(methylenedioxy)benzene derivative represented by general formula (1). (In the formula, R1 and R2 represent an alkyl group having 1-10 carbon atoms, and R1 and R2 have different numbers of carbon atoms.
    Type: Application
    Filed: June 21, 2012
    Publication date: July 31, 2014
    Applicant: NIPPON CHEMICAL INDUSTRIAL CO., LTD.
    Inventors: Zhenfeng Zhang, Tsuneo Imamoto, Ken Tamura
  • Publication number: 20130172597
    Abstract: An industrially advantageous method for producing an optically active 1,2-bis(dialkylphosphino)benzene derivative of the present invention is provided. The method is characterized in that a phosphine-borane compound represented by the following general formula (1) is subjected to a deboronation reaction, followed by lithiation, then the reaction product is subjected to reaction with an alkyldihalogenophosphine represented by RaPX?2, and thereafter the reaction product is subjected to reaction with a Grignard reagent represented by RbMgX? to produce an optically active 1,2-bis(dialkylphosphino)benzene derivative (A). R1 and R2 respectively represent an alkyl group having 1 to 8 carbon atoms, and the number of carbon atoms is different between R1 and R2. Ra is either R1 or R2 and Rb is the other of R1 and R2. X, X?, and X? each represent a halogen atom.
    Type: Application
    Filed: July 3, 2011
    Publication date: July 4, 2013
    Applicant: NIPPON CHEMICAL INDUSTRIAL CO., LTD.
    Inventors: Ken Tamura, Masashi Sugiya, Tsuneo Imamoto
  • Patent number: 8198471
    Abstract: A novel phosphine compound capable of forming a metal complex useful as a catalyst for various asymmetric synthesis reactions, a production method thereof, and a metal complex comprising the aforementioned compound as a ligand.
    Type: Grant
    Filed: March 8, 2010
    Date of Patent: June 12, 2012
    Assignee: Nippon Chemical Industrial Co., Ltd.
    Inventors: Ken Tamura, Masashi Sugiya, Tsuneo Imamoto
  • Patent number: 8076480
    Abstract: 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.
    Type: Grant
    Filed: July 24, 2008
    Date of Patent: December 13, 2011
    Assignees: National University Corporation Chiba University, Nippon Chemical Industrial Co., Ltd.
    Inventors: Tsuneo Imamoto, Kazuhiro Yoshida, Miwako Nishimura, Aya Koide
  • Publication number: 20100234626
    Abstract: It is an object of the present invention to provide a novel phosphine compound capable of forming a metal complex useful as a catalyst for various asymmetric synthesis reactions, a production method thereof, and a metal complex comprising the aforementioned compound as a ligand. A 2,2?-bis(dialkylphosphino)biphenyl compound represented by the formula (A-1). A compound represented by the formula (1) is appropriate as a catalyst for an asymmetric synthesis reaction. The biphenyl compound represented by the formula (A-1) can be obtained by subjecting a compound represented by the formula (A-2) to a coupling reaction to obtain an intermediate represented by the formula (A-3), and then subjecting the intermediate to a deboranation reaction. In the formula (A-1), R1 and R2 each independently represent a C1-C10 alkyl group, R3 represents a monovalent substituent, and n represents an integer of 0 to 4.
    Type: Application
    Filed: March 8, 2010
    Publication date: September 16, 2010
    Applicant: NIPPON CHEMICAL INDUSTRIAL CO., LTD.
    Inventors: Ken Tamura, Masashi Sugiya, Tsuneo Imamoto
  • Patent number: 7723548
    Abstract: The present invention aims to provide a bis(phosphine) boronium salt to be used as a building block or the like for producing a diphosphine compound effective mainly for various kinds of transition metal-catalyzed reactions and further to provide a preferable production method of the bis(phosphine) boronium salt and a bis(phosphine) boronium salt to be produced by the production method. The present invention provides a bis(phosphine) boronium salt having the structure defined by the following formula (1).
    Type: Grant
    Filed: January 30, 2007
    Date of Patent: May 25, 2010
    Assignee: Japan Science and Technology Agency
    Inventors: Kentaro Yamaguchi, Hiroshi Danjo, Toru Koizumi, Tsuneo Imamoto
  • Patent number: 7649117
    Abstract: Disclosed is a process of preparing an optically active ?-hydroxycarboxylic acid derivative comprising asymmetrically hydrogenating a ?-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.
    Type: Grant
    Filed: July 24, 2008
    Date of Patent: January 19, 2010
    Assignees: National University Corporation Chiba University, Nippon Chemical Industrial Co., Ltd.
    Inventors: Tsuneo Imamoto, Kazuhiro Yoshida, Miwako Nishimura, Aya Koide
  • Patent number: 7608709
    Abstract: 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.
    Type: Grant
    Filed: February 23, 2006
    Date of Patent: October 27, 2009
    Assignees: National University Corporation Chiba University, Nippon Chemical Industrial Co., Ltd.
    Inventors: Tsuneo Imamoto, Kazuhiro Yoshida, Keitaro Sugita
  • Patent number: 7534920
    Abstract: 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.
    Type: Grant
    Filed: March 5, 2008
    Date of Patent: May 19, 2009
    Assignees: Nippon Chemical Industrial Co., Ltd., National University Corporation Chiba University
    Inventors: Tsuneo Imamoto, Kazuhiro Yoshida, Youichi Saitoh, Aya Koide