Journal ArticleNature Synthesis · September 1, 2024
Racemic ketones are converted to stereoisomerically enriched homoallylic alcohols by copper-catalysed enantioconvergent allylation. ...
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Journal ArticleJournal of the American Chemical Society · July 2024
We introduce a method for the (Z)-selective aminoallylation of a range of ketones to prepare allylic 1,2-amino tertiary alcohols with excellent diastereo- and enantioselectivity. Copper-catalyzed reductive couplings of 2-azatrienes with aryl/alkyl a ...
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Journal ArticleJournal of the American Chemical Society · December 2023
We report a palladium-catalyzed method for 4,3- or 4,1-selective alkenylamination of terminal dienes. Three-component couplings proceed with alkenyl triflates and several amines, giving vicinal carboamination with a Xantphos-supported catalyst and distal d ...
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Journal ArticleJournal of the American Chemical Society · September 2021
We introduce a new reagent class, 2-azatrienes, as a platform for catalytic enantioselective synthesis of allylic amines. Herein, we demonstrate their promise by a diastereodivergent synthesis of syn- and anti-1,2-diamines through their Cu-bi ...
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Journal Article · July 26, 2021
We introduce a new reagent class, 2-azatrienes, as a platform for catalytic enantioselective synthesis of allylic amines. Herein, we demonstrate their promise by diasteredivergent and enantioselective synthesis of <i>syn</i>- and <i& ...
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Journal Article · 2021
We introduce a new reagent class, 2-azatrienes, as a platform for catalytic enantioselective synthesis of allylic amines. Herein, we demonstrate their promise by diasteredivergent and enantioselective synthesis of syn - and anti -1,2-diamines by Cu-bis(pho ...
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Journal ArticleACS catalysis · November 2020
The exploitation of the α-trifluoromethylamino group as an amide surrogate in peptidomimetics and drug candidates has been on the rise. In a large number of these cases, this moiety bears stereochemistry with the stereochemical identity having impor ...
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Journal ArticleChemical communications (Cambridge, England) · August 2020
Here we report on chelating ligands for Signal Amplification By Reversible Exchange (SABRE) catalysts that permit hyperpolarisation on otherwise sterically hindered substrates. We demonstrate 1H enhancements of ∼100-fold over 8.5 T thermal for 2 ...
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Journal ArticleOrganic letters · March 2020
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We report the enantioselective formation of quaternary stereogenic centers by the intermolecular addition of malononitrile, an acyl anion equivalent, and related pronucleophiles to several 1,3-disubstituted acyclic 1,3-dienes in the presence of a Pd-PHOX c ...
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Journal ArticleOrganic letters · February 2020
We describe a strategy for the enantio- and diastereoselective synthesis of homoallylic α-trifluoromethyl amines by the catalytic hydroalkylation of terminal dienes. Trifluoromethyl-substituted isatin-derived azadienolate nucleophiles undergo γ-selective a ...
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Journal ArticleACS Catalysis · January 17, 2020
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Catalytic enantioselective synthesis of small-molecule building blocks with allylic stereogenic centers is an important objective in organic synthesis, but preparing this motif wherein the adjacent olefin is 1,2-disubstituted in a single step is a tremendo ...
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Journal Article · 2020
We describe a strategy for the enantio- and diastereoselective synthesis of homoallylic α-trifluoromethyl amines by the catalytic hydroalkylation of terminal dienes. Trifluoromethylsubstituted isatin-derived azadienolate nucleophiles undergo γ-selective al ...
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Journal ArticleOrganic letters · September 2019
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We report the catalytic enantio- and diastereoselective preparation of aminocyclopropanes by the cyclopropanation of terminal and (Z)-internal 2-azadienes with donor/acceptor carbenes derived from α-diazoesters. The resulting cyclopropanes bear quat ...
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Journal ArticleSynlett : accounts and rapid communications in synthetic organic chemistry · July 2019
The development of new strategies for the preparation of chiral amines is an important objective in organic synthesis. In this Synpacts, we summarize our approach for catalytically accessing nucleophilic aminoalkyl metal species from 2-azadienes, an ...
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Journal ArticleJournal of the American Chemical Society · May 2019
In this study, we establish that conjugated enynes undergo selective 1,4-hydroamination under Pd catalysis to deliver chiral allenes with pendant allylic amines. Several primary and secondary aliphatic and aryl-substituted amines couple with a wide range o ...
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Journal ArticleChemical science · May 2019
We describe the development of Pd-PHOX-catalysed enantioselective couplings of internal dienes with malononitrile and other activated C-pronucleophiles. Reactions are dramatically accelerated by the addition of Et3N·HBArF 4 as a Brønsted acid co-catalyst, ...
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Journal ArticleACS catalysis · January 2019
We report the synthesis of α-trifluoromethyl benzylic amines through the vicinal fluoroarylation of gem-difluoro-2-azadienes. Our studies indicate that XPhos plays an important role as a phase transfer catalyst that promotes the addition of A ...
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Journal ArticleACS Catalysis · September 7, 2018
We report the development of highly enantio- and regioselective Pd-catalyzed intermolecular hydroaminations of challenging 1,4-disubstituted acyclic dienes. Several aryl/alkyl-disubstituted dienes and a sterically differentiated alkyl/alkyl-disubstituted d ...
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Journal ArticleJournal of the American Chemical Society · June 2018
Here we report highly efficient and chemoselective azadiene-imine reductive couplings catalyzed by (Ph-BPE)Cu-H that afford anti-1,2-diamines. In all cases, reactions take place with either aldimine or ketimine electrophiles to deliver a single diastereome ...
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Journal ArticleJournal of the American Chemical Society · February 2018
We report a highly enantioselective Pd-PHOX-catalyzed intermolecular hydroalkylation of acyclic 1,3-dienes. Meldrum's acid derivatives and other activated C-pronucleophiles, such as β-diketones and malononitriles, react with a variety of aryl- and alkyl-su ...
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Journal ArticleJournal of the American Chemical Society · January 2018
We introduce a new strategy for synthesis of chiral amines: couplings of α-aminoalkyl nucleophiles generated by enantioselective migratory insertion of 2-azadienes to a Cu-H. In this report, we demonstrate its application in catalytic reductive coupling of ...
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Journal ArticleAngewandte Chemie · September 25, 2017
AbstractDiazirines are an attractive class of potential molecular tags for magnetic resonance imaging owing to their biocompatibility and ease of incorporation into a large variety of molecules. As recently reported,
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Journal ArticleAngewandte Chemie (International ed. in English) · September 2017
Diazirines are an attractive class of potential molecular tags for magnetic resonance imaging owing to their biocompatibility and ease of incorporation into a large variety of molecules. As recently reported, 15 N2 -diazirine can be h ...
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Journal ArticleOrganic letters · August 2017
The 1,3-diamine motif appears in numerous complex molecules, yet there are few methods for the stereoselective construction of this moiety. Herein, we demonstrate a stereocontrolled synthesis of 1,3-diamines, which bear up to three contiguous stereogenic c ...
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Journal ArticleOrganic letters · July 2017
We report the direct preparation of 1,3-amino alcohols that contain up to three contiguous stereogenic centers by the umpolung coupling of imines and epoxides. Nucleophilic 2-azaallyl anions, generated from imines, are stereoselectively added to epoxides t ...
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Journal ArticleJournal of the American Chemical Society · June 2017
Signal amplification by reversible exchange (SABRE) is an inexpensive, fast, and even continuous hyperpolarization technique that uses para-hydrogen as hyperpolarization source. However, current SABRE faces a number of stumbling blocks for translation to b ...
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Journal ArticleJournal of the American Chemical Society · May 2017
We report a method for the catalytic, enantioselective intermolecular addition of aliphatic amines to acyclic 1,3-dienes. In most cases, reactions proceed efficiently at or below room temperature in the presence of 5 mol % of a Pd catalyst bearing a PHOX l ...
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Journal ArticleThe journal of physical chemistry. C, Nanomaterials and interfaces · March 2017
Signal Amplification by Reversible Exchange (SABRE) is a fast and convenient NMR hyperpolarization method that uses cheap and readily available para-hydrogen as a hyperpolarization source. SABRE can hyperpolarize protons and heteronuclei. Here we fo ...
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Journal ArticleChemistry (Weinheim an der Bergstrasse, Germany) · July 2016
NMR with thermal polarization requires relatively concentrated samples, particularly for nuclei with low abundance and low gyromagnetic ratios, such as (15) N. We expand the substrate scope of SABRE, a recently introduced hyperpolarization method, to allow ...
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Journal ArticleScience Advances · March 25, 2016
Conventional magnetic resonance (MR) faces serious sensitivity limitations which can be overcome by hyperpolarization methods, but the most common method (dynamic nuclear polarization) is complex and expensive, and applications are limited by short spin li ...
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Chapter · January 1, 2015
This chapter covers the advances made since 2003 in the development of catalysts that can control the stereochemical outcome of olefin metathesis reactions. Various enantioselective processes, such as enantioselective ring-opening/cross-metathesis (EROCM) ...
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Journal ArticleProceedings of the National Academy of Sciences of the United States of America · May 2013
Berninamycin is a member of the pyridine-containing thiopeptide class of antibiotics that undergoes massive posttranslational modifications from ribosomally generated preproteins. Berninamycin has a 2-oxazolyl-3-thiazolyl-pyridine core embedded in a 35-ato ...
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Journal ArticleOrganometallics · June 2012
Seven bipyridine adducts of molybdenum imido alkylidene bispyrrolide complexes of the type Mo(NR)(CHCMe(2)R')(Pyr)(2)(bipy) (1a-1g; R = 2,6-i-Pr(2)C(6)H(3) (Ar), adamantyl (Ad), 2,6-Me(2)C(6)H(3) (Ar'), 2-i-PrC(6)H(4) (Ar(iPr)), 2-ClC(6)H(4) (Ar(Cl)), 2-t- ...
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Journal ArticleACS chemical biology · March 2012
Nitrogen heterocycles are the key functional and structural elements in both RNA and DNA, in half a dozen of the most important coenzymes, and in many synthetic drug scaffolds. On the other hand, only 3 of 20 proteinogenic amino acids have nitrogen heteroc ...
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Journal ArticleChemistry & biology · September 2011
2,5-Dihydrophenylalanine (H(2)Phe) is a multipotent nonproteinogenic amino acid produced by various Actinobacteria and Gammaproteobacteria. Although the metabolite was discovered over 40 years ago, details of its biosynthesis have remained largely unknown. ...
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Journal ArticleJournal of the American Chemical Society · April 2011
Pacidamycins are a family of uridyl peptide antibiotics that inhibit the translocase MraY, an essential enzyme in bacterial cell wall biosynthesis that to date has not been clinically targeted. The pacidamycin structural skeleton contains a doubly inverted ...
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Journal ArticleAngewandte Chemie (International ed. in English) · January 2010
Chiral olefin metathesis catalysts enable chemists to access enantiomerically enriched small molecules with high efficiency; synthesis schemes involving such complexes can be substantially more concise than those that would involve enantiomerically pure su ...
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Journal ArticleJournal of the American Chemical Society · November 2009
The present study provides spectroscopic and experimental evidence demonstrating that degenerate metathesis is critical to the effectiveness of this emerging class of chiral catalysts. Isolation and X-ray characterization of both diastereomeric complexes, ...
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Journal ArticleJournal of the American Chemical Society · January 2009
A total synthesis of the Aspidosperma alkaloid quebrachamine in racemic form is first described. A key catalytic ring-closing metathesis of an achiral triene is used to establish the all-carbon quaternary stereogenic center and the tetracyclic structure of ...
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Journal ArticleNature · December 2008
Discovery of efficient catalysts is one of the most compelling objectives of modern chemistry. Chiral catalysts are in particularly high demand, as they facilitate synthesis of enantiomerically enriched small molecules that are critical to developments in ...
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Journal ArticleJournal of the American Chemical Society · April 2006
The first examples of catalytic asymmetric ring-closing metathesis (ARCM) reactions of enol ethers are reported. To identify the most effective catalysts, various chiral Mo- and Ru-based catalysts were screened. Although chiral Ru catalysts (those that do ...
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