[ { "id": "authors:p6vet-s5c82", "collection": "authors", "collection_id": "p6vet-s5c82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211214-174138725", "type": "conference_item", "title": "Reductive elimination from palladium(II) via a [\u03c02s + \u03c02s + \u03c32s + \u03c32s] pericyclic reaction", "author": [ { "family_name": "Cusumano", "given_name": "Alexander", "orcid": "0000-0002-2914-2008", "clpid": "Cusumano-Alexander-Q" }, { "family_name": "Goddard", "given_name": "William Andrew", "orcid": "0000-0003-0097-5716", "clpid": "Goddard-W-A-III" }, { "family_name": "Stoltz", "given_name": "Brian Mark", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "The fundamental step responsible for enantioinduction in the inner-sphere asym. Tsuji allylic alkylation is C-C bond formation through a unique seven-membered pericyclic transition state. We investigate how the electronic structure of the transition metal center enables the C-C bond forming process. Phase inversion introduced by d orbitals renders the Pd-catalyzed [\u03c02s + \u03c02s + \u03c32s + \u03c32s] reaction symmetry-allowed in the ground state - proceeding through a transition state with Craig-M\u00f6bius-like aromaticity. We connect these findings to ubiquitous bonding concepts, such as Frontier MO theory and valence bonding theory.", "publisher": "Caltech Library", "publication_date": "2021-08" }, { "id": "authors:8680x-shp96", "collection": "authors", "collection_id": "8680x-shp96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201221-084129753", "type": "conference_item", "title": "Synthesis of carboxylic acid and dimer ester surrogates to constrain the abundance and distribution of\n molecular products in \u03b1-pinene and \u03b2-pinene secondary organic aerosol", "author": [ { "family_name": "Kenseth", "given_name": "Christopher M.", "orcid": "0000-0003-3188-2336", "clpid": "Kenseth-Christopher-M" }, { "family_name": "Hafeman", "given_name": "Nicholas J.", "orcid": "0000-0001-7525-7597", "clpid": "Hafeman-Nicholas-J" }, { "family_name": "Huang", "given_name": "Yuanlong", "orcid": "0000-0002-6726-8904", "clpid": "Huang-Yuanlong" }, { "family_name": "Dalleska", "given_name": "Nathan F.", "orcid": "0000-0002-2059-1587", "clpid": "Dalleska-Nathan-F" }, { "family_name": "Stoltz", "given_name": "Brian Mark", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" }, { "family_name": "Seinfeld", "given_name": "John H.", "orcid": "0000-0003-1344-4068", "clpid": "Seinfeld-J-H" } ], "abstract": "Liq. chromatog./neg. electrospray ionization mass spectrometry [LC/(-)ESI-MS] is routinely employed to characterize the\nidentity and abundance of mol. products in secondary org. aerosol (SOA) derived from monoterpene oxidn. Due to a\nlack of authentic stds., however, com. terpenoic acids (e.g., cis-pinonic acid) are typically used as surrogates to\nquantify both monomeric and dimeric SOA constituents. Here, we synthesize a series of enantiopure, pinene-derived\ncarboxylic acid and dimer ester homologues. We find that the (-)ESI efficiencies of the dimer esters are 19 to 36 times\nhigher than that of cis-pinonic acid, demonstrating that the mass contribution of dimers to monoterpene SOA has\nbeen significantly overestimated in past studies. Using the measured (-)ESI efficiencies of the carboxylic acids and\ndimer esters as more representative surrogates, we det. that mol. products measureable by LC/(-)ESI-MS account for\nonly 21.8 \u00b1 2.6% and 18.9 \u00b1 3.2% of the mass of SOA formed from ozonolysis of \u03b1-pinene and \u03b2-pinene, resp. The 28-\n36 identified monomers (C\u2087\u208b\u2081\u2080H\u2081\u2080\u208b\u2081\u2088O\u2083\u208b\u2086) constitute 15.6-20.5% of total SOA mass, whereas only 1.3-3.3% of the SOA\nmass is attributable to the 46-62 identified dimers (C\u2081\u2085\u208b\u2081\u2089H\u2082\u2084\u208b\u2083\u2082O\u2084\u208b\u2081\u2081). The distribution of identified \u03b1-pinene and \u03b2-pinene SOA mol. products is examd. as a function of carbon no. (n_C), av. carbon oxidn. state (OS_C), and volatility\n(C*). The obsd. order of magnitude difference in (-)ESI efficiency between monomers and dimers is expected to be\nbroadly applicable to other biogenic and anthropogenic SOA systems analyzed via (-) or (+) LC/ESI-MS, and\ndemonstrates that the use of unrepresentative surrogates can lead to substantial systematic errors in quant. LC/ESI-MS\nanalyses of SOA.", "publisher": "Caltech Library", "publication_date": "2020-08" }, { "id": "authors:y1kag-8n124", "collection": "authors", "collection_id": "y1kag-8n124", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190325-092717158", "type": "conference_item", "title": "Enantioselective synthesis of gem-disubstituted N-Boc diazaheterocycles via decarboxylative asymmetric allylic alkylation", "author": [ { "family_name": "Sun", "given_name": "Alexander", "orcid": "0000-0001-6639-4469", "clpid": "Sun-Alexander-W" }, { "family_name": "Stoltz", "given_name": "Brian Mark", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "An enantioselective synthesis of diverse N4-Boc-protected a,a-disubstituted piperazin-2-ones using the\npalladiumcatalyzed decarboxylative allylic alkylation reaction has been achieved. Using a chiral Pd-catalyst derived from\nan electron deficient PHOX ligand, chiral piperazinones are synthesized in high yields and enantioselectivity. The chiral\npiperazinone products can be deprotected and reduced to valuable gem-disubstituted piperazines. This reaction is\nfurther extended to enable the enantioselective synthesis of a,a-disubstituted tetrahydropyrimidin-2-ones, which are\nhydrolyzed into corresponding chiral b2,2-amino acids.", "publisher": "Caltech Library", "publication_date": "2019-04" }, { "id": "authors:e6186-a2280", "collection": "authors", "collection_id": "e6186-a2280", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181108-143733231", "type": "conference_item", "title": "Cyclic alkanes transfer dehydrogenation using homogeneous iridium pincer catalysts", "author": [ { "family_name": "Al Saihati", "given_name": "Zainab", "orcid": "0000-0002-3837-9736", "clpid": "Al-Saihati-Z" }, { "family_name": "Haibach", "given_name": "Michael C.", "orcid": "0000-0001-8383-5633", "clpid": "Haibach-M-C" }, { "family_name": "Swisher", "given_name": "Nicholas A.", "orcid": "0000-0002-5320-407X", "clpid": "Swisher-N-A" }, { "family_name": "Stoltz", "given_name": "Brian M.", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" }, { "family_name": "Grubbs", "given_name": "Robert H.", "orcid": "0000-0002-0057-7817", "clpid": "Grubbs-R-H" } ], "abstract": "Described herein is a method for the transfer dehydrogenation of cyclic alkanes to alkenes and aroms. using synthesized homogeneous iridium pincer complexes and H_2 acceptor. This method is a promising alternative for the industrial energy intensive dehydrogenation process as iridium pincer catalysts have greater selectivity relative to heterogeneous catalysts and require significantly lower reaction temps.", "publisher": "Caltech Library", "publication_date": "2018-08" }, { "id": "authors:03pzg-hmp58", "collection": "authors", "collection_id": "03pzg-hmp58", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180413-085522795", "type": "conference_item", "title": "Award Address (ACS Award for Creative Work in Synthetic Organic Chemistry sponsored by MilliporeSigma). Complex natural products as a driving force for discovery in organic chemistry", "author": [ { "family_name": "Stoltz", "given_name": "Brian", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "Our lab. is deeply interested in the discovery and development of new reaction methodol. en route to the chem. synthesis of\ncomplex bioactive mols. Over the course of the past seventeen years, research in our group at the California Institute of\nTechnol. has been initiated in the general area of synthetic chem., with a focus on the development of new strategies for the prepn. of complex mols., including natural products that possess interesting structural, biol., and phys. properties. Concurrent to this program of target driven synthesis is a strong effort directed toward the development of new techniques and reaction methods, which are useful for a range of applications. Typically, the complex target structure is used as an inspiration for the discovery of new reactions and technologies that may eventually be regarded as general synthetic methodol. Consequently, this approach provides access to (a) novel, medicinally relevant structures, (b) a general method for their synthesis, and (c) new synthetic methods that will be beneficial for a host of applications. Thus, In the process of completing the synthesis of a range of important compds., we have developed a no. of new methods that enabled their access. These topics will be\ndiscussed in the lecture.", "publisher": "Caltech Library", "publication_date": "2018-03" }, { "id": "authors:yyr8j-bgq68", "collection": "authors", "collection_id": "yyr8j-bgq68", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180712-081511897", "type": "conference_item", "title": "Total synthesis of (\u00b1)-phomoidride D: A 22 year odyssey", "author": [ { "family_name": "Leung", "given_name": "Joyce", "clpid": "Leung-Joyce" }, { "family_name": "Bederman", "given_name": "Aaron", "clpid": "Bederman-A" }, { "family_name": "Njardarson", "given_name": "Jon", "clpid": "Njardarson-J" }, { "family_name": "Spiegel", "given_name": "David", "clpid": "Spiegel-D-S" }, { "family_name": "Murphy", "given_name": "Graham", "clpid": "Murphy-G" }, { "family_name": "Hama", "given_name": "Naota", "clpid": "Hama-Naota" }, { "family_name": "Shirahata", "given_name": "Tatsuya", "clpid": "Shirahata-Tatsuya" }, { "family_name": "Twenter", "given_name": "Barry", "clpid": "Twenter-B" }, { "family_name": "Dong", "given_name": "Ping", "clpid": "Dong-Ping" }, { "family_name": "McDonald", "given_name": "Ivar", "orcid": "0000-0003-0356-0655", "clpid": "McDonald-I" }, { "family_name": "Inoue", "given_name": "Munenori", "clpid": "Inoue-Munenori" }, { "family_name": "Taniguchi", "given_name": "Nobuaki", "clpid": "Taniguchi-Nobuaki" }, { "family_name": "McMahon", "given_name": "Travis", "clpid": "McMahon-T" }, { "family_name": "Tao", "given_name": "Nancy", "clpid": "Tao-Nancy" }, { "family_name": "Schneider", "given_name": "Chris", "clpid": "Schneider-C" }, { "family_name": "Stoltz", "given_name": "Brian", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" }, { "family_name": "Wood", "given_name": "John", "clpid": "Wood-J-L" } ], "abstract": "Recent efforts in our labs. have culminated in a completed synthesis of the phomoidride D via a strategy that evolved over a 22-yr period. The evolution of this strategies will be discussed.", "publisher": "Caltech Library", "publication_date": "2018-03" }, { "id": "authors:ej7em-za941", "collection": "authors", "collection_id": "ej7em-za941", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170913-084235803", "type": "conference_item", "title": "Recent developments in stereoselective iridium-catalyzed allylic alkylation methodologies", "author": [ { "family_name": "Shockley", "given_name": "Samantha", "clpid": "Shockley-S-E" }, { "family_name": "Hethcox", "given_name": "Caleb", "clpid": "Hethcox-C" }, { "family_name": "Stoltz", "given_name": "Brian", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "We report our ongoing studies in the field of iridium-catalyzed allylic alkylation chem. The first regio-,\ndiastereo-, and enantioselective transition-metal-catalyzed allylic alkylation reaction forming vicinal tertiary\nand all-carbon quaternary stereocenters between prochiral enolates and an aliph.-substituted electrophile is\ndisclosed. Crit. to the success of this new reaction is the identity and ubiquity of the chloride counterion in\naddn. to the use of proton sponge, the combination of which affords excellent regio- and enantioselectivities along with good yields and diastereoselectivities. Addnl., a no. of transformations were carried out on the alkylation products to demonstrate the value of this method in rapidly accessing highly functionalized, stereochem. rich polycyclic scaffolds. Further exploration of this chem. has continued to expand the scope of these types of transformations with respect to the nucleophile and electrophile. Our recent efforts in this field will be discussed.", "publisher": "Caltech Library", "publication_date": "2017-08" }, { "id": "authors:xjath-wzj74", "collection": "authors", "collection_id": "xjath-wzj74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170919-130910278", "type": "conference_item", "title": "Twists and turns of lactam research", "author": [ { "family_name": "Stoltz", "given_name": "Brian M.", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "The importance of the amide bond cannot be overstated. Typical amides are planar structures, however, amide\nbonds can be highly twisted such as in bicyclic bridgehead lactams. The distortion of the orbitals from planarity\nand the pyramidalization of the nitrogen from sp toward sp dramatically affect the stability and reactivity of\nanti-Bredt amides. In 2006, our group published the first unambiguous synthesis and characterization of 2-\nquinuclidonium tetrafluoroborate. Since then we have been fascinated with the synthesis and characterization\nof such strained reactive lactams. We have also pursued the synthesis of a series of novel stereogenic lactams\nthat can be employed as intermediates in multi-step synthesis. The lecture will discuss our efforts in these\nvibrant research areas. Looking ahead, the limits are still open for the synthesis of more or less reactive but\nstructurally unique and often twisted amides.", "publisher": "Caltech Library", "publication_date": "2017-08" }, { "id": "authors:yzan4-78e47", "collection": "authors", "collection_id": "yzan4-78e47", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170503-152924409", "type": "conference_item", "title": "Complex natural products as a driving force for discovery in organic chemistry", "author": [ { "family_name": "Stoltz", "given_name": "Brian M.", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "Our lab. is deeply interested in the discovery and development of new reaction methodol. en route to the chem. synthesis of complex bioactive mols. Over the course of the past ten years, research in our group at the California Institute of Technol. has been initiated in the general area of synthetic chem., with a focus on the development of new strategies for the prepn. of complex mols., including natural products that possess interesting structural, biol., and phys. properties. Concurrent to this program of target driven synthesis is a strong effort directed toward the development of new techniques and reaction methods, which will be useful for a range of applications. Typically, the complex target structure is used as an inspiration for the discovery of new reactions and technologies that may eventually be regarded as general synthetic methodol. Consequently, this approach provides access to a) novel, medicinally relevant structures, b) a general method for their synthesis, and c) new synthetic methods that will be beneficial for a host of applications. Our group has been heavily involved in the synthesis of complex natural products such as the cyanthiwigins, quinocarcin, lemonomycin, and the dragmacidins. These naturally occurring mols. possess promising biol. properties ranging from activity against antibiotic-resistant bacteria, to antiproliferative, to anti-HIV action. Furthermore, they are structurally novel and are inherently a challenge to the state-of-the-art in synthetic\nchem. In the process of completing the synthesis of these important compds., we have developed a no. of new methods that enabled their access. These topics will be discussed in the lecture.", "publisher": "Caltech Library", "publication_date": "2017-04" }, { "id": "authors:mmn8r-cp850", "collection": "authors", "collection_id": "mmn8r-cp850", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140811-150157474", "type": "conference_item", "title": "Asymmetric synthesis of QUINAP via dynamic kinetic resolution", "author": [ { "family_name": "Bhat", "given_name": "Vikram", "orcid": "0000-0001-5621-5121", "clpid": "Bhat-V" }, { "family_name": "Virgil", "given_name": "Scott C.", "orcid": "0000-0001-8586-5641", "clpid": "Virgil-S-C" }, { "family_name": "Stoltz", "given_name": "Brian M.", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "A Pd-catalyzed, atroposelective C-P coupling process has been developed for the asym. synthesis of QUINAP and its derivs. in high enantiomeric excess. Bromide, triflate (OTf) and 4-methanesulfonylbenzenesulfonate (OSs) precursors were studied, leading in the case of the triflate to a novel dynamic kinetic resoln. involving isomerization of an arylpalladium intermediate. The operationally simple methods described in this communication afford these important ligands in good to high yields and selectivity using low catalyst loading (\u22643 mol % Pd).", "publisher": "Caltech Library", "publication_date": "2014-08" }, { "id": "authors:40907-smv43", "collection": "authors", "collection_id": "40907-smv43", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140811-150326033", "type": "conference_item", "title": "Development and application of a palladium-catalyzed enantioselective conjugate addition", "author": [ { "family_name": "Holder", "given_name": "Jeffrey C.", "clpid": "Holder-J-C" }, { "family_name": "Shockley", "given_name": "Samantha E.", "clpid": "Shockley-S-E" }, { "family_name": "Marziale", "given_name": "Alexander N.", "clpid": "Marziale-A-N" }, { "family_name": "Gatti", "given_name": "Michele", "clpid": "Gatti-M" }, { "family_name": "Kikushima", "given_name": "Kotaro", "clpid": "Kikushima-Kotaro" }, { "family_name": "Stoltz", "given_name": "Brian M.", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "The first enantioselective palladium-catalyzed, asym. construction of all-carbon quaternary stereocenters via 1, 4-addn. of arylboronic acids to cyclic, \u03b2-substituted enones is reported. A wide range of arylboronic acids and cyclic enones are reacted utilizing a catalyst prepd. from palladium(II) trifluoroacetate and a chiral pyridinooxazoline ligand to yield enantioenriched products bearing benzylic stereocenters. Recently, this methodol. has been expanded to support the reaction of heterocyclic chromone and 4-quinolone conjugate acceptors. Notably, this transformation is insensitive to air or moisture, providing a practical and operationally simple method of synthesizing enantioenriched stereocenters. The application of this reaction toward the total syntheses of members of the taiwaniaquinone sesquiterpenoid family of natural products is discussed.", "publisher": "Caltech Library", "publication_date": "2014-08" }, { "id": "authors:q6ky7-7fm06", "collection": "authors", "collection_id": "q6ky7-7fm06", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130410-144615697", "type": "conference_item", "title": "Development of a palladium-catalyzed enantioselective conjugate addition of arylboronic acids to cyclic conjugate acceptors", "author": [ { "family_name": "Holder", "given_name": "Jeffrey C.", "clpid": "Holder-J-C" }, { "family_name": "Kikushima", "given_name": "Kotaro", "clpid": "Kikushima-Kotaro" }, { "family_name": "Marziale", "given_name": "Alexander N.", "clpid": "Marziale-A-N" }, { "family_name": "Gatti", "given_name": "Michele", "clpid": "Gatti-M" }, { "family_name": "Stoltz", "given_name": "Brian M.", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "The first enantioselective Pd-catalyzed construction of all-carbon quaternary stereocenters\nvia 1,4-addn. of arylboronic acids to \u03b2-substituted cyclic enones is reported. Reaction of a\nwide range of arylboronic acids and cyclic enones using a catalyst prepd. from Pd(OCOCF_3)_2 and a chiral pyridinooxazoline ligand yields enantioenriched products bearing benzylic\nstereocenters. Notably, this transformation is tolerant to air and moisture, providing a\npractical and operationally simple method of synthesizing enantioenriched all-carbon\nquaternary stereocenters.", "publisher": "Caltech Library", "publication_date": "2013-04" }, { "id": "authors:t15s3-y5q40", "collection": "authors", "collection_id": "t15s3-y5q40", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120822-154455462", "type": "conference_item", "title": "Sensitive and selective nucleic acid capture with shielded covalent probes", "author": [ { "family_name": "Vieregg", "given_name": "Jeffrey R.", "clpid": "Vieregg-Jeffrey-R" }, { "family_name": "Nelson", "given_name": "Hosea M.", "orcid": "0000-0002-4666-2793", "clpid": "Nelson-H-M" }, { "family_name": "Stoltz", "given_name": "Brian", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" }, { "family_name": "Pierce", "given_name": "Niles A.", "orcid": "0000-0003-2367-4406", "clpid": "Pierce-N-A" } ], "abstract": "Nucleic acid probes are used for diverse applications in vitro, in situ, and in vivo. In any setting, their power is limited by imperfect selectivity (binding of undesired targets) and incomplete affinity (binding is reversible and not all desired targets are bound). These limitations stem from reliance on base pairing to both reject off-targets and retain desired targets. To address this selectivity/affinity tradeoff, shielded covalent probes achieve selectivity via conformation change and durable capture via covalent crosslinking of a photoactive nucleoside analog. In vitro assays show that mismatches are efficiently rejected and desired targets are durably captured. For probes designed to reject two-nucleotide mismatches, desired targets are captured nearly quant. Single-nucleotide mismatches are discriminated near the thermodn. limit. The probes operate isothermally and crosslinking activation is rapid with low-cost light sources. If desired, crosslinks can be reversed to release the target after capture. We envision a wide array of applications.", "publisher": "Caltech Library", "publication_date": "2012-08" }, { "id": "authors:gs4vt-fgw87", "collection": "authors", "collection_id": "gs4vt-fgw87", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120822-092222870", "type": "conference_item", "title": "Novel approach to antitumor antibiotics: Using the power of benzyne in synthesis", "author": [ { "family_name": "Stoltz", "given_name": "Brian M.", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "We have initiated a research program directed toward the tetrahydroisoquinoline (THIQ) antitumor antibiotics, a class of bioactive alkaloids with existing clin. applications. Central to our approach is the development of new aryne annulation methods for the synthesis of isoquinolines. Our initial application of this method in a THIQ synthesis was to a concise asym. total synthesis of (-)-quinocarcin. Our current work in the area will be discussed.", "publisher": "Caltech Library", "publication_date": "2012-08" }, { "id": "authors:pz0h8-44h96", "collection": "authors", "collection_id": "pz0h8-44h96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120816-071730866", "type": "conference_item", "title": "Complex natural products as a driving force for discovery in organic chemistry", "author": [ { "family_name": "Stoltz", "given_name": "B. M.", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "This lecture will focus on the development of new catalytic bond forming reactions developed in our lab and applications\nin complex mol. synthesis.", "publisher": "Caltech Library", "publication_date": "2010-12" }, { "id": "authors:hj73z-bq429", "collection": "authors", "collection_id": "hj73z-bq429", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120815-153559315", "type": "conference_item", "title": "Intertwined nature of chemical synthesis and the discovery process", "author": [ { "family_name": "Stoltz", "given_name": "B. M.", "orcid": "0000-0001-9837-1528", "clpid": "Stoltz-B-M" } ], "abstract": "This lecture will describe recent advances in our lab. in the area of asym. catalysis and applications in multi-step\nsynthesis.", "publisher": "Caltech Library", "publication_date": "2010-12" } ]