A Facile Synthesis of Porphyrinoid Scaffolds using Dipolar Cycloaddtions

Start Date: March 01 2018 - 05:30 PM

End Date: March 01 2018 - 10:00 PM

Audience: Student, Faculty and Staff

Category: Club Event

Location: S-112

Description:

THE QCC STUDENT AFFILIATES OF THE AMERICAN CHEMICAL SOCIETY & THE CHEMISTRY CLUB PROUDLY SPONSORS THE LONG ISLAND SUBSECTION OF THE NY-ACS SEMINAR OF DR. JUNIOR GONZALES, DEPARTMENT OF CHEMISTRY, HUNTER COLLEGE OF THE CITY OF NEW YORK TITLE OF TALK: "A FACILE SYNTHESIS OF PORPHYRINOID SCAFFOLDS USING DIPOLAR CYCLOADDTIONS" SYNOPSIS: DE NOVO CHLORIN SYNTHESIS CAN BE QUITE CHALLENGING TO ACHIEVE IN GOOD YIELDS AND MANY CHLORINS ARE NOT STABLE TO PHOTOBLEACHING AND/OR ARE READILY OXIDIZED, THIS HAS LIMIT THE USE OF THESE PORPHYRINOIDS IN CLINICAL RESEARCH AND CARE. EXPLOITATION OF CHLORINS ALSO DEPENDS ON THE AVAILABILITY OF THESE CHROMOPHORES, TO PRODUCE VALUABLE DATA IN THE TRIALS FOR PHOTODYNAMIC THERAPY AND AS NANO-CARRIERS FOR DRUG DELIVERY. THE REDUCED SYMMETRY OF THE CHLORIN MACROCYCLE FURTHER COMPLICATES THE ADDITION OF THE EXOCYCLIC MOTIFS. A FACILE APPROACH TO A STABLE, SYNTHETIC CHLORIN WITH A FUSED N-methyl pyrrolidine USES A SARCOSINE-BASED AZOMETHINE YLIDE AND CYCLO ADDITION ON 5, 10, 15, 20-tetrakis-(2, 3, 4, 5, 6-pentalfluorophenyl)-porphyrin (TPPF20) IS INCREASING USED, BUT HIS APPROACH HAS LIMITATIONS. WE REPORT THE DIVERGENT SYNTHESIS OF CHLORIN SCAFFOLDS STARTING WITH THE SAME TPPF20 USING A GLYCINE-BASED YLIDE. UNEXPECTEDLY, WE FOUND THAT CAREFUL CONTROL OF THE 1,3-dipolar cycloaddition REACTION ALLOWS DIRECTED FORMATION OF NEW CHLORINS, INCLUDING THE FUSED N-H pyrrolidine, TWO DIMERS, AND THE SAME N-methyl chlorin PRODUCT FROM THE SARCOSINE YLIDE REACTION. THE MECHANISM BEGINS WITH THE FORMATION OF AN ALCHOLIC GLYCINE, WHICH THEN REACTS WITH TPPF20 TO FORM A KEY N-(hydroxymethyl)-17, 18- pyrrolidinyl-chlorin INTERMEDIATE. DEFORMYLATION OF THIS INTERMEDIATE AFFORDS THE N-H pyrrolidine, whereas, a Cannizzaro-type OF REACTION PROMOTES A HYDRIDE ATTACK TO AN IMINE CHLORIN CATION TO YIELD THE SAME N- methyl chlorin AS THE SARCOSINE YLIDE. THE EXOCYCLIC NH-pyrrolidine PROVIDES A UNIQUE HEMISPHERE-MODE OF ATTACHING CHIRAL MOIETIES THAT AVOIDS FORMATION OF DIASTEROMERS AT THE BRIDGING CARBONS. THE MECHANISM ALSO UNFOLDS A NEW ROUTE TO FURNISH A HEMIAMINAL CHLORIN AND (N-carbaldehyde)-17, 18-pyrrolidinyl- chrorin). ALL ARE WELCOME! DIRECTIONS: http://www.qcc.cuny.edu/about/driving.html - AFTER DINNER SEMINAR: AT A NEARBY RESTAURANT, $25 PER PERSON. CO-SPONSORS-STEM ACADEMY, STEM RESEARCH CLUB, CSTEP CLUB, SCIENCE RESEARCH ALLIANCE, HAITIAN CLUB, BIOLOGY CLUB, STUDENTS' HEALTH CLUB, ENVIRONMENTAL SUSTAINABILITY CLUB, ASAP CLUB, KOREAN STUDENT ASSOCIATION, LAMBDA SIGMA PHI THETA KAPPA, SACNAS QCC CHAPTER, ASIAN SOCIETY 

 


Contact Name: Marlon Moreno

Contact Phone: 718.281.5017

Contact Email: mmoreno@qcc.cuny.edu

Campus Cultural Centers

Kupferberg Holocaust Center (KHC)Opens in a new window
Kupferberg Holocaust Center Opens in a new window

Using the lessons of the Holocaust to educate current and future generations about the ramifications of unbridled prejudice, racism and stereotyping.

Queensborough Performing Arts CenterOpens in a new window
QPAC: Performing Arts CenterOpens in a new window

QPAC is an invaluable entertainment company in this region with a growing national reputation. The arts at QPAC continues to play a vital role in transforming lives and building stronger communities.

Queensborough Art GalleryOpens in a new window
QCC Art GalleryOpens in a new window

The QCC Art Gallery of the City University of New York is a vital educational and cultural resource for Queensborough Community College, the Borough of Queens and the surrounding communities.