Jeremy A. May

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Name: May, Jeremy

Organization: University of Houston , USA

Department: Department of Chemistry

Title: Associate(PhD)

Chemicals
References

Synthesis of azasilacyclopentenes and silanols via Huisgen cycloaddition-initiated C–H bond insertion cascades

Co-reporter:Jiun-Le Shih;Santa Jansone-Popova;Christopher Huynh

Chemical Science (2010-Present) 2017 vol. 8(Issue 10) pp:7132-7137

Publication Date(Web):2017/09/25

DOI:10.1039/C7SC03130K

An unusual transition metal-free cascade reaction of alkynyl carbonazidates was discovered to form azasilacyclopentenes. Mild thermolysis afforded the products via a series of cyclizations, rearrangements, and an α-silyl C–H bond insertion (rather than the more common Wolff rearrangement, 1,2-shift, or β-silyl C–H insertion) to form silacyclopropanes. A mechanistic proposal for the sequence was informed by control experiments and the characterization of reaction intermediates. The substrate scope and post-cascade transformations were also explored.

Brønsted Acid Catalyzed Homoconjugate Addition of Organotrifluoroborates to Arylated Cyclopropyl Ketones

Co-reporter:Truong N. Nguyen, Thien S. Nguyen, and Jeremy A. May

Organic Letters 2016 Volume 18(Issue 15) pp:3786-3789

Publication Date(Web):July 13, 2016

DOI:10.1021/acs.orglett.6b01795

A novel and practical homoconjugate addition of alkenyl, alkynyl, heteroaryl, and aryl trifluoroborates to arylated cyclopropyl ketones to synthesize γ,γ-disubstituted ketones is reported. A preliminary mechanistic proposal involving ketone protonation, an intermediary carbocation, and intermolecular nucleophile addition has been made based on control studies.

Stereoelectronic factors in bridgehead C–H bond insertion: studies toward the total synthesis of maoecrystal V

Co-reporter:Santa Jansone-Popova, Jeremy A. May

Tetrahedron 2016 Volume 72(Issue 26) pp:3734-3747

Publication Date(Web):30 June 2016

DOI:10.1016/j.tet.2016.03.101

A strategy for the total synthesis of maoecrystal V is presented. The key interior vicinal quaternary carbon centers will be formed via sequential bridgehead C–H bond insertion and enolate functionalization. Studies herein validate the C–H bond insertion as feasible in model studies, though there are significant effects on the selectivity for the bridgehead position from neighboring groups. Both inductive electron withdrawing elements and sterics play a role in deactivating that position, with the former having a greater effect. Forming the second quaternary carbon is possible via enolate acylation and alkylation. Lastly, an approach to synthesize the cyclohexenone ring of maoecrystal V is described.

Hydrazone-Initiated Carbene/Alkyne Cascades to Form Polycyclic Products: Ring-Fused Cyclopropenes as Mechanistic Intermediates

Co-reporter:Phong Q. Le

Journal of the American Chemical Society 2015 Volume 137(Issue 38) pp:12219-12222

Publication Date(Web):September 22, 2015

DOI:10.1021/jacs.5b08157

A hydrazone-based carbene/alkyne cascade produced a variety of bridged and fused polycyclic products. NaOSiMe3 is a superior base for conversion of hydrazones to diazoalkanes. A key mechanistic intermediate, a ring-fused cyclopropene, has been isolated and characterized.

Biomimetic Synthesis and Studies Toward Enantioselective Synthesis of Flindersial Alkaloids

Co-reporter:Ravikrishna Vallakati;Brian J. Lundy;Santa Jansone-Popova

Chirality 2015 Volume 27( Issue 1) pp:14-17

Publication Date(Web):

DOI:10.1002/chir.22134

Abstract

A strategy allowing both stereocontrol and control over structural isomer formation has been defined for the antimalarial flindersial alkaloids. The recently reported flinderoles were demonstrated to be derived from the natural product borrerine. The structural isomers of flinderoles, the borreverines, were also produced in vitro along with the flinderoles through the dimerization of borrerine in acidic conditions. This result is thought to replicate the biosynthesis of these compounds. Flinderoles A, B, and C, desmethylflinderole C, isoborreverine, and dimethylisoborreverine can each be synthesized in three steps from tryptamine. Furthermore, progress toward a concise enantioselective synthesis of flinderoles A, B, and C is described. This work includes enantioselective conjugate addition to an unprotected indole-appended enone. Chirality 27:14–17, 2015. © 2013 Wiley Periodicals, Inc.

Organocatalyzed Asymmetric Conjugate Addition of Heteroaryl and Aryl Trifluoroborates: a Synthetic Strategy for DiscoipyrroleD

Co-reporter:Jiun-Le Shih;Thien S. Nguyen ; Jeremy A. May

Angewandte Chemie 2015 Volume 127( Issue 34) pp:10069-10073

Publication Date(Web):

DOI:10.1002/ange.201503528

Abstract

Bis-heteroaryl or bis-aryl stereocenters were formed by an organocatalytic enantioselective conjugate addition using the respective trifluoroborate salts as nucleophiles. Control studies suggested that fluoride dissociation is necessary in the anhydrous conditions. This strategy is applicable to the synthesis of discoipyrrole D, an inhibitor of BR5 fibroblast migration.

Organocatalyzed Asymmetric Conjugate Addition of Heteroaryl and Aryl Trifluoroborates: a Synthetic Strategy for DiscoipyrroleD

Co-reporter:Jiun-Le Shih;Thien S. Nguyen ; Jeremy A. May

Angewandte Chemie International Edition 2015 Volume 54( Issue 34) pp:9931-9935

Publication Date(Web):

DOI:10.1002/anie.201503528

Abstract

Carbene cascades for the formation of bridged polycyclic rings

Co-reporter:Santa Jansone-Popova, Phong Q. Le, Jeremy A. May

Tetrahedron 2014 70(27–28) pp: 4118-4127

Publication Date(Web):

DOI:10.1016/j.tet.2014.03.060

Indoles Synthesized from Amines via Copper Catalysis

Co-reporter:Ronald Besandre, Miguel Jaimes, and Jeremy A. May

Organic Letters 2013 Volume 15(Issue 7) pp:1666-1669

Publication Date(Web):March 13, 2013

DOI:10.1021/ol400444g

N-Substituted indoles are synthesized from primary amines through a tandem reaction sequence. Initial condensation of the amine with an α-(o-haloaryl)ketone or aldehyde is followed by intramolecular aryl amination catalyzed by CuI. A variety of anilines and alkyl amines, including those with significant steric demands, are converted to indoles in high yields and with varying indole substitution.

Synthesis of Bridged Polycyclic Ring Systems via Carbene Cascades Terminating in C–H Bond Insertion

Co-reporter:Santa Jansone-Popova

Journal of the American Chemical Society 2012 Volume 134(Issue 43) pp:17877-17880

Publication Date(Web):October 19, 2012

DOI:10.1021/ja308305z

A carbene cascade reaction that constructs functionalized bridged bicyclic systems from alkynyl diazoesters is presented. The cascade proceeds through diazo decomposition, carbene/alkyne metathesis, and C–H bond insertion. The diazoesters are easily synthesized from cyclic ketones. Substrate ring size and substitution patterns control the connectivity and diastereomeric preference found in the products.

Biomimetic Synthesis of the Antimalarial Flindersial Alkaloids

Co-reporter:Ravikrishna Vallakati

Journal of the American Chemical Society 2012 Volume 134(Issue 16) pp:6936-6939

Publication Date(Web):April 10, 2012

DOI:10.1021/ja301387k

A biomimetic strategy for the synthesis of the antimalarial flindersial alkaloids is described. Flinderoles A, B, and C, desmethylflinderole C, isoborreverine, and dimethylisoborreverine were all synthesized in three steps from tryptamine. The key step is an acid-promoted dimerization of the natural product borrerine. This approach is thought to mirror the biosynthesis of these compounds.

A General Method for the Enantioselective Synthesis of α-Chiral Heterocycles

Co-reporter:Phong Q. Le, Thien S. Nguyen, and Jeremy A. May

Organic Letters 2012 Volume 14(Issue 23) pp:6104-6107

Publication Date(Web):November 16, 2012

DOI:10.1021/ol3030605

The enantioselective formation of stereocenters proximal to unprotected heterocycles has been accomplished. Thus, vinyl boronic acids are added to heterocycle-appended enones via a modified-BINOL catalyst. Catalyst design was key to enable a general reaction. High yields and useful er’s are observed for a host of common heteroaryls.