Search Patents
  • Liquid crystal composition and liquid crystal shutter
    Patent number: 6436312
    Abstract: A liquid crystal composition comprises a host material capable of exhibiting a smectic C phase, and a chiral dopant material which imparts or enhances chirality in the host material. The composition exhibits &tgr;-Vmin curves. The chiral dopant material comprises at least first and second chiral centers. The chiral centers individually produce, in the liquid crystal composition, different and complementary temperature coefficients of spontaneous polarization within a predetermined temperature range. The chiral centers are present in the liquid crystal composition in relative amounts such that regions of the &tgr;-Vmin curves across the predetermined temperature range are substantially coincident.
    Type: Grant
    Filed: April 13, 2000
    Date of Patent: August 20, 2002
    Assignees: Sharp Kabushiki Kaisha, The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britian and Northern Ireland
    Inventors: Rachel Patricia Tuffin, Andrew John Slaney, John Clifford Jones, Mitsuhiro Koden
  • Method and catalyst system for stereoselectively inverting a chiral center of a chemical compound
    Publication number: 20010021519
    Abstract: The present invention provides a catalyst system and a process for stereoselectively inverting a chiral center of a chemical compound. The catalyst system of the present invention comprises (i) a catalytic amount of a metal catalyst; (ii) an enzyme capable of oxidizing a chemical compound at a chiral center, or microorganism cells capable of producing an enzyme which is capable of oxidizing a chemical compound at a chiral center; (iii) an oxidant; and (iv) a hydrogen source. The process of the present invention comprises treating a chemical compound having a chiral center with the catalyst system of this invention.
    Type: Application
    Filed: January 22, 2001
    Publication date: September 13, 2001
    Applicant: NSC Technologies, L.L.C. Delaware Limited Liability Corporation
    Inventors: Weiguo Liu, Scott Laneman, David John Ager, Paul Phillip Taylor
  • Chiral swallow-tailed liquid crystals and its fabrication method
    Patent number: 6245256
    Abstract: Novel chiral swallow-tailed liquid crystals synthesized from chiral material comprised of alkyl(s)-2-{6-[4-(4′-alkyloxyphenyl)benzoyloxy]-2-naphthyl}propionates having a rigid core, a chiral center directly linked to the rigid core, a chiral tail, and a swallow-tailed group linked to the chiral tail. The chiral center and the swallow-tailed group are arranged at the same side in the molecular structure of the chiral material. These structural characteristics enable the chiral material to have same property of threadholdless antiferroelectricity, and the advantage of simple manufacturing process. The chiral material shows an optimum application effect in liquid crystal displays.
    Type: Grant
    Filed: October 4, 1999
    Date of Patent: June 12, 2001
    Assignee: Chunghwa Picture Tubes, Inc.
    Inventors: Shune-Long Wu, Jang-Jeng Liang
  • Liquid crystal compounds having a chiral fluorinated terminal portion
    Patent number: 6309561
    Abstract: Fluorine-containing, chiral liquid crystal compounds comprise (a) a chiral fluorochemical terminal portion comprising (i) at least one chiral center, which can optionally be heteroatom-substituted; (ii) a terminal fluoroalkyl, fluoroether, perfluoroalkyl, or perfluoroether group; and (iii) an alkylene or fluoroalkylene group optionally containing at least one catenary ether oxygen atom; (b) a chiral or achiral terminal portion consisting of a hydrocarbon or hydrocarbon ether group, and, when chiral, comprising at least one chiral center, which can optionally be heteroatom-substituted; and (c) a central core connecting the terminal portions; the alkylene or fluoroalkylene group of the chiral fluorochemical terminal portion having at least 3 in-chain atoms and being located between the chiral center of the chiral fluorochemical terminal portion and the central core. The compounds have smectic mesophases or latent smectic mesophases and are useful, for example, in liquid crystal display devices.
    Type: Grant
    Filed: December 24, 1997
    Date of Patent: October 30, 2001
    Assignee: 3M Innovative Properties Company
    Inventors: Masakazu Hasegawa, Michael P. Keyes, Marc D. Radcliffe, Patricia M. Savu, Daniel C. Snustad, Terence D. Spawn
  • Liquid crystal compounds having a chiral fluorinated terminal portion
    Patent number: 6030547
    Abstract: Fluorine-containing, chiral liquid crystal compounds comprise (a) a chiral fluorochemical terminal portion comprising (i) at least one chiral center, which can optionally be heteroatom-substituted; (ii) a terminal fluoroalkyl, fluoroether, perfluoroalkyl, or perfluoroether group; and (iii) an alkylene or fluoroalkylene group optionally containing at least one caternary ether oxygen atom; (b) a chiral or achiral terminal portion consisting of a hydrocarbon or hydrocarbon ether group, and, when chiral, comprising at least one chiral center, which can optionally be heteroatom-substituted; and (c) a central core connecting the terminal portions; the alkylene or fluoroalkylene group of the chiral fluorochemical terminal portion having at least 3 in-chain atoms and being located between the chiral center of the chiral fluorochemical terminal portion and the central core. The compounds have smectic mesophases or latent smectic mesophases and are useful, for example, in liquid crystal display devices.
    Type: Grant
    Filed: December 24, 1997
    Date of Patent: February 29, 2000
    Assignee: 3M Innovative Properties Company
    Inventors: Masakazu Hasegawa, Michael P. Keyes, Marc D. Radcliffe, Patricia M. Savu, Daniel C. Snustad, Terence D. Spawn
  • Chiral liquid crystal compounds having a fluorinated terminal portion
    Patent number: 6139924
    Abstract: Novel liquid crystal compounds are provided which exhibit less temperature dependent switching properties, for the reliable and consistent operation of liquid crystal devices. The liquid crystal compounds comprise (a) an achiral fluorochemical terminal portion that comprises a terminal fluoroalkyl, fluoroether, perfluoroalkyl, or perfluoroether group; a chiral terminal portion comprising a saturated or unsaturated chiral hydrocarbon or chiral hydrocarbon ether group comprising a chiral center; and a central core connecting the terminal portions; said chiral terminal portion having at least three in-chain atoms (an "extended group") between said chiral center of the chiral terminal portion and said central core.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: October 31, 2000
    Assignee: 3M Innovative Properties Company
    Inventors: Michael P. Keyes, Marc D. Radcliffe, Steven J. Martin, Daniel C. Snustad, Kenneth A. Epstein
  • Thioacids and thioacid salts for determining the enantiomeric excess of chiral compounds containing an electrophilic carbon center
    Patent number: 7741513
    Abstract: The invention provides novel chiral compounds including 2-methoxy-2-trifluoromethylphenylacetic thioacid useful to react with and analyze other chiral compounds that have an electrophilic chiral carbon center.
    Type: Grant
    Filed: January 16, 2008
    Date of Patent: June 22, 2010
    Inventor: Jack E. Richman
  • TUNABLE CHIRAL COMPOSITION, MULTI-COLOR LCD CONTAINING TUNABLE CHIRAL COMPOSITION AND METHOD FOR MAKING TUNABLE CHIRAL POLYMER
    Publication number: 20130063690
    Abstract: A tunable chiral composition includes a liquid crystal material, a tunable chiral material with at least one chiral center and at least one ethylenic double bond and a photo-initiator. The tunable chiral composition is substantially cross-linking agent free.
    Type: Application
    Filed: September 6, 2012
    Publication date: March 14, 2013
    Inventors: Hsien-Wei Chiang, Chih-Yuan Wang
  • Thioacids and thioacid salts for determining the enantiomeric excess of chiral compounds containing an electrophilic carbon center
    Publication number: 20090181462
    Abstract: The invention provides novel chiral compounds including 2-methoxy-2-trifluoromethylphenylacetic thioacid useful to react with and analyze other chiral compounds that have an electrophilic chiral carbon center.
    Type: Application
    Filed: January 16, 2008
    Publication date: July 16, 2009
    Inventor: Jack E. Richman
  • Method for stereoselectively inverting a chiral center of a chemical compound using an enzyme and a metal catalyst
    Patent number: 6365380
    Abstract: A process for stereoselectively inverting a chiral center of a chemical compound is disclosed. The process first consists of forming a mixture of the chemical comopund, an enzymatic system, and a metal catalyst. Next, the process stereoselectively dehydrogenates a group attached to the chiral center with the enzymatic system in the presence of an oxidant to produce a dehydrogenated group, Lastly, the process hydrogenates the dehydrogenated group with the metal catalyst in the presence of a hydrogen source to stereoselectively invert the chiral center of the chemical compound.
    Type: Grant
    Filed: January 22, 2001
    Date of Patent: April 2, 2002
    Assignee: PCBU Services, Inc.
    Inventors: Weiguo Liu, Scott Laneman, David John Ager, Paul Phillip Taylor
  • Asymmetric catalysis based on chiral phospholanes and hydroxyl phospholanes
    Patent number: 6337406
    Abstract: Chiral phosphine ligands derived from chiral natural products including D-mannitol and tartaric acid. The ligands contain one or more 5-membered phospholane rings with multiple chiral centers, and provide high stereoselectivity in asymmetric reactions.
    Type: Grant
    Filed: August 19, 1999
    Date of Patent: January 8, 2002
    Assignee: The Penn State Research Foundation
    Inventor: Xumu Zhang
  • Asymmetric catalysis based on chiral phospholanes and hydroxyl phospholanes
    Publication number: 20040176618
    Abstract: Chiral phosphine ligands derived from chiral natural products including D-mannitol and tartaric acid. The ligands contain one or more 5-membered phospholane rings with multiple chiral centers, and provide high stereoselectivity in asymmetric reactions.
    Type: Application
    Filed: March 2, 2004
    Publication date: September 9, 2004
    Applicant: The Penn State Research Foundation
    Inventor: Xumu Zhang
  • Asymmetric catalysis based on chiral phospholanes and hydroxyl phospholanes
    Publication number: 20030040629
    Abstract: Chiral phosphine ligands derived from chiral natural products including D-mannitol and tartaric acid. The ligands contain one or more 5-membered phospholane rings with multiple chiral centers, and provide high stereoselectivity in asymmetric reactions.
    Type: Application
    Filed: November 6, 2001
    Publication date: February 27, 2003
    Applicant: The Penn State Research Foundation
    Inventor: Xumu Zhang
  • Asymmetric catalysis based on chiral phospholanes and hydroxyl phospholanes
    Patent number: 6946569
    Abstract: Chiral phosphine ligands derived from chiral natural products including D-mannitol and tartaric acid. The ligands contain one or more 5-membered phospholane rings with multiple chiral centers, and provide high stereoselectivity in asymmetric reactions.
    Type: Grant
    Filed: March 2, 2004
    Date of Patent: September 20, 2005
    Assignee: The Penn State Research Foundation
    Inventor: Xumu Zhang
  • Asymmetric catalysis based on chiral phospholanes and hydroxyl phospholanes
    Patent number: 6727377
    Abstract: Chiral phosphine ligands derived from chiral natural products including D-mannitol and tartaric acid. The ligands contain one or more 5-membered phospholane rings with multiple chiral centers, and provide high stereoselectivity in asymmetric reactions.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: April 27, 2004
    Assignee: The Penn State Research Foundation
    Inventor: Xumu Zhang
  • Chiral swallow-tailed liquid crystal and its fabrication method
    Patent number: 6740256
    Abstract: A chiral swallow-tailed liquid crystal is provided. The present chiral swallow-tailed liquid crystal is synthesized from a chiral material. The present chiral swallow-tailed liquid crystal is composed of the compound of (N,N′-diethyl (s)-2-{6-[4-(4′-alkoxyphenyl)benzoyloxy]-2-naphthyl}propanamide or the compound of (N,N′-dipropyl(s)-2-{6-[4-(4′-alkoxyphenyl)benzoyloxy]-2-naphthyl}propanamide. The chiral center of the present chiral compound is directly linked to its rigid core, and the chiral tail of this compound is linked with a swallow-tailed group. The chiral center and swallow-tailed group are arranged at the same side in the molecular structure. This structural characteristic enables the chiral compound to have the same property of thresholdless antiferroelectricity, and the advantage of simple manufacturing process. The present chiral compound shows an optimum application effect in liquid crystal displays.
    Type: Grant
    Filed: April 2, 2003
    Date of Patent: May 25, 2004
    Assignee: Chunghwa Picture Tubes, Ltd.
    Inventors: Shune-Long Wu, Wen-Jiunn Hsieh
  • INTERMEDIATES OF SITAGLIPTIN AND PREPARATION PROCESS THEREOF
    Publication number: 20130281695
    Abstract: Disclosed are intermediates of Sitagliptin, a preparation process thereof, and a process for synthesizing Sitagliptin using these intermediates. Sitagliptin is synthesized by using chiral amino compounds as a raw material, without having to build a chiral center with a chiral asymmetric catalytic hydrogenation, and high-pressure hydrogenation is avoided.
    Type: Application
    Filed: December 1, 2011
    Publication date: October 24, 2013
    Applicant: ZHEJIANG HISOAR PHARMACEUTICAL CO., LTD.
    Inventors: Xianhua Pan, Weijin Li, Qunhui Zhang, Libo Ruan, Wansheng Yu, Fei Deng, Tianhua Ma, Mingwang Huang, Minhuan He
  • Intermediates of sitagliptin and preparation process thereof
    Patent number: 9187419
    Abstract: Disclosed are intermediates of Sitagliptin, a preparation process thereof, and a process for synthesizing Sitagliptin using these intermediates. Sitagliptin is synthesized by using chiral amino compounds as a raw material, without having to build a chiral center with a chiral asymmetric catalytic hydrogenation, and high-pressure hydrogenation is avoided.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: November 17, 2015
    Assignee: ZHEJIANG HISOAR PHARMACEUTICAL CO., LTD.
    Inventors: Xianhua Pan, Weijin Li, Qunhui Zhang, Libo Ruan, Wansheng Yu, Fei Deng, Tianhua Ma, Mingwang Huang, Minhuan He
  • Chiral metallocene compounds and preparation thereof by attachment of chiral center
    Patent number: 5208357
    Abstract: There are provided enantiomerically enhanced chiral substituted cyclopentadienyl ligands and compounds thereof, and a process for their making comprising contacting a substituted fulvene or derivative thereof with an enantiomerically enhanced or pure nucleophile having at least one chiral center. There are further provided enantiomerically enhanced chiral organometallic complexes having one or more chiral substituted cyclopentadienyl groups.
    Type: Grant
    Filed: December 31, 1990
    Date of Patent: May 4, 1993
    Assignee: Exxon Chemical Patents, Inc.
    Inventor: Eric A. Mintz
  • SYSTEM AND METHOD FOR MULTI CHIRAL DETECTION
    Publication number: 20220115095
    Abstract: A method comprising: receiving a plurality of signals representing spectral emissions resulting from an interaction between a laser field and a respective plurality of analytes, wherein at least some of the analytes comprise multi-center chiral molecules; at a training stage, training a machine learning model on a training set comprising: (i) the plurality of signals, and (ii) labels associated with a configuration of a chirality in each of the plurality of analytes; and at an inference stage, applying the machine learning model to a target signal representing spectral emission associated with a target analyte comprising a multi-center chiral molecule, to determine chiral characteristic of the target analyte.
    Type: Application
    Filed: October 14, 2021
    Publication date: April 14, 2022
    Inventors: Oren COHEN, Ofer NEUFELD, Or PELEG, Omri WENGROWICZ
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