NaOH Bartfield
@naohbartfield.bsky.social
Ph.D. Candidate @YaleChem (@HerzonLab) - Frederich Lab Alum (@fsuresearch) - NSF Fellow - #CASFutureLeaders 2024 - Complex Molecule Synthesis - ✡︎
Hopping on here to say I've been offered a postdoctoral appointment soon in the laboratory of Prof. David Liu at the Broad Institute! This is a big pivot from natural product synthesis, but I am eager to contribute everything I can to gene editing and protein evolution!
More top-notch natural product synthesis from the Herzon lab Incredible work from Brandon Alexander and @naohbartfield.bsky.social Now in @jacs.acspublications.org ASAP
Total Synthesis of Chartelline C
Chartellines are cytotoxic marine alkaloids that were isolated in the late 1980s. Their unique, heavily oxidized structures, comprising a spirocyclic β-lactam, a halogenated indolenine, a chloroenamide, and a 2-haloimidazole, have motivated extensive efforts toward their synthesis. However, only a single synthesis of any chartelline has been reported in the nearly 40 years since their isolation. Here, we describe a route to chartelline C (3) from the macrolactam 21, an intermediate we employed en route to the related securine and securamine alkaloids. The key challenges in converting macrolactam 21 to chartelline C (3) involve stereocontrolled construction of the C2–C3 enamide, isomerization of the trans-C10–C11 alkene, formation of the strained spirocyclic β-lactam, and chlorination of the enamide. Each of these challenges was addressed by an unconventional approach. The macrolactam 21 was converted to cis-enamide (2Z,10E)-24 by in situ masking of the C12 ketone, followed by stereoselective acid-catalyzed elimination of the C2 carbinolamide. The C10–C11 trans-alkene was isomerized by a photolytic process; control experiments suggest that this isomerization occurs by energy transfer. The β-lactam was constructed by a solid-state reaction involving the adsorption of the bromoindolenine 26 onto activated basic alumina. Late-stage enamide chlorination, which had been an obstacle in prior approaches, was accomplished by a novel photoredox-mediated halogenation. These latter studies suggest that N-haloanomeric amides and N-haloguanidines may act as halogen atom transfer agents under thermal or photolytic conditions. Finally, we show that chartelline C (3) reacts with sulfur-based nucleophiles, suggesting that further studies of their biological activity may be warranted.
pubs.acs.org
Our approach to the total synthesis of chartelline C, out now in JACS. Photochemistry and unique topology gave way to some really interesting reactivity! pubs.acs.org/doi/10.1021/...
Total Synthesis of Chartelline C
Chartellines are cytotoxic marine alkaloids that were isolated in the late 1980s. Their unique, heavily oxidized structures, comprising a spirocyclic β-lactam, a halogenated indolenine, a chloroenamide, and a 2-haloimidazole, have motivated extensive efforts toward their synthesis. However, only a single synthesis of any chartelline has been reported in the nearly 40 years since their isolation. Here, we describe a route to chartelline C (3) from the macrolactam 21, an intermediate we employed en route to the related securine and securamine alkaloids. The key challenges in converting macrolactam 21 to chartelline C (3) involve stereocontrolled construction of the C2–C3 enamide, isomerization of the trans-C10–C11 alkene, formation of the strained spirocyclic β-lactam, and chlorination of the enamide. Each of these challenges was addressed by an unconventional approach. The macrolactam 21 was converted to cis-enamide (2Z,10E)-24 by in situ masking of the C12 ketone, followed by stereoselective acid-catalyzed elimination of the C2 carbinolamide. The C10–C11 trans-alkene was isomerized by a photolytic process; control experiments suggest that this isomerization occurs by energy transfer. The β-lactam was constructed by a solid-state reaction involving the adsorption of the bromoindolenine 26 onto activated basic alumina. Late-stage enamide chlorination, which had been an obstacle in prior approaches, was accomplished by a novel photoredox-mediated halogenation. These latter studies suggest that N-haloanomeric amides and N-haloguanidines may act as halogen atom transfer agents under thermal or photolytic conditions. Finally, we show that chartelline C (3) reacts with sulfur-based nucleophiles, suggesting that further studies of their biological activity may be warranted.
pubs.acs.org
Always a great conference with student presentations, talks from Boehringer, Merck, BMS, Pfizer and keynotes from Martin Tomanik (NYU) and Ryan Shenvi (Scripps) @shenvi.bsky.social (And yes, @naohbartfield.bsky.social is one of the student speakers) June 27 @ Conn College New London CT
Dr. KC Ortiz, Process Chem Enjoyer@kcortiz.bsky.social · last yr.ACS CVS tomorrow! I'm hyped! Can't wait to see @naohbartfield.bsky.social 's talk and try to annoy @bagphos.bsky.social !!!
ACS CVS tomorrow! I'm hyped! Can't wait to see @naohbartfield.bsky.social 's talk and try to annoy @bagphos.bsky.social !!!
Post from Tw*tter: Happy Pride month 🏳️🌈 Trans people are being targeted, excluded, and killed simply for being themselves. Kick off this month by considering the hire of trans workers if you're in the position, or donating to the Transgender Law Center (transgenderlawcenter.org/donate/) if you can
Donate - Transgender Law Center
Supporters like you are critical to our success by providing the resources necessary to advance the rights of transgender and gender nonconforming people, defend our victories, and ensure our movement's strength. Thank you!
transgenderlawcenter.org
If you're interested in a break from the doom-and-gloom, may I recommend our article, online today @nature.com A solution to the pyrazole alkylation problem, leveraging S-to-NR atom replacement. Skeletal editing has strategic value, outside of late-stage! www.nature.com/articles/s41...
My boss is Seth Herzon in case people want to go for him instead of me
NaOH Bartfield@naohbartfield.bsky.social · last yr.Boss is talking about my PhD work on Wednesday morning in room 30E if yall wanna tune in 👀
Boss is talking about my PhD work on Wednesday morning in room 30E if yall wanna tune in 👀
Scott Bagley@bagphos.bsky.social · last yr.The @organicdivision.org has a really packed schedule with tons of amazing symposia for #ACSSpring2025 in San Diego To help you find it all and plan your schedule here is our hand grid schedule #ChemSky
Boss is talking about my PhD work on Wednesday morning in room 30E if yall wanna tune in 👀
Scott Bagley@bagphos.bsky.social · last yr.The @organicdivision.org has a really packed schedule with tons of amazing symposia for #ACSSpring2025 in San Diego To help you find it all and plan your schedule here is our hand grid schedule #ChemSky
Headed to the @acs.org meeting in San Diego? Make sure to set the time zone in your app/online schedule to Pacific Time!! #ACSSpring2025 #ChemSky
This is going to do absolutely nothing to curb antisemitism and will, if anything, make things worse. Smokescreen after smokescreen for attacks on universities. All of us whose university is not on this list cannot breathe a sigh of relief - we will not be spared. www.nytimes.com/2025/03/08/u...
Trump Pulled $400 million From Columbia. Other Schools Could Be Next.
The administration has circulated a list that includes nine other campuses, accusing them of failure to address antisemitism.
nytimes.com
Do they call it a "Roman Salute" on this app too or can we just soberly call them Nazis on Bluesky
2 year ago today, Samantha Mensah (chemistry PhD candidate at UCLA) passed away. Part of her legacy is in my heart and I hope one day, I can hug her again.💔 إِنَّا لِلَّٰهِ وَإِنَّا إِلَيْهِ رَاجِعُون everloved.com/life-of/sama... @blackinchem.bsky.social #Chemsky
Read Ms. Samantha "Sammy" Theresa Mensah's Obituary & Leave Condolences
<p>Samantha “Sammy” Theresa Mensah passed away on February 22, 2023. She was born in New York City on September 18, 1994 to Elder Cruz and Owusu Asenso Mensah.…
everloved.com
Some of those replies are the equivalent of: “To keep my electrolytes in balance I only use aqueous n-butyl lithium for deprotonation”
I am currently experiencing antisemitism on twitter dot com for telling people not to drink methylene blue 🫡
Just got a 4% yield on something i was convinced was impossible and yknow what i'll take it
Hey science friends? I know that many of you are concerned about the perceived neutral and apolitical role of science in decisionmaking. But scientists are being targeted. We didn't start it. And advocating *for the role of scientific evidence in policymaking* is not unprofessional advocacy.
I think science communicators do a great job. I do not think you can out-science-communicate fascist ideology. Its on a whole different axis of logic
Colombian President Gustavo Petro's full post ordering an increase of import tariffs on U.S. goods, says he doesn't really like traveling to the U.S. because it's “a bit boring” and invokes the ancestors
Phil Lewis@phillewis.bsky.social · 2y agoBOGOTÁ, Colombia (AP) — Colombian president orders increase of import tariffs on US goods in retaliation to similar order from President Trump.
The future was supposed to have flying cars, not AI John McAfee coming back from the dead to promote a scam crypto coin
Really inspiring tandem of papers from the Knowles and Yoon (ft. Dadphos @bagphos.bsky.social) groups in ChemRxiv this morning! chemrxiv.org/engage/chemr... chemrxiv.org/engage/chemr...
Pulling out of the department lot and saw someone with UF plates was parked next to my car with FSU plates. Can never escape it
At cvs one bottle of flonase is $22. At costco, the generic costs $22 for 10 times the amount buy in bulk folks
blue maga idiots on this app make me yearn to bolt awake in 360 BC Carthage wondering if it was all a dream
💙RoamingCaptainRoman💙@roamingcaptain.bsky.social · 2y ago
The increasing American sentiment to annex the bulk of North America is terrifying. Its a country appealing fascism, brutish imperialism, and oligarchy.
