Una cuestión muy importante cuando usted está enseñando a la química orgánica es la manera de dibujar estructuras químicas correctamente. Es muy fácil. Todo lo que tienes que hacer es tomar la estructura ChemDraw y añade un montón de acentos al azar. Por ejemplo:
Siguiente lección: cómo traducir recetas sintéticas
What’s all this about? Well it started like this when I posted the following on The Wall:
24 Apr ‘07
Let’s say you were a graduate student in organic chemistry at Harvard ‘60 – ‘62 (I was), and that you passed 8 of the first 9 cumes (I did) and that you talked Woodward into letting you work on you own idea 9 months after you got there because passing 8 cumes was all you needed to start your PhD work (also true) and were remembered by most concerned as arrogant unfortunately true) and that you were god-awful in the lab (true) and left organic chemistry to go back to medicine. Further suppose that organic chemistry always seemed natural and fun, and that you happened to see a squib in the 12 April Nature about the total synthesis of Lyconadin B, Googled it and found the structure and commentary in TotallySynthetic.Com and fell back in love with organic chemistry, and wished to get up to speed so you could enjoy reading about the field again..
How and where would you start? What are the best introductory texts for organic chemistry, physical organic chemistry? Are there still texts, or is everything on the web now? What is the best place to read about NMR and structure determination (just beginning back then), computational chemistry (practically nonexistent back then — they were still sweating H2+). Also is Debye Huckel theory still what we used to think about it — good for slightly impure distilled water, but not much else. Something better is needed for cell water which is 0.3 molar..
I love the irreverance of the chemical blogs. Have at it folks.
and
Thanks
I got this back the same day from Excimer:
I’ll bite: my favorite introductory chem text is by Jones- it has pretty widespread use throughout undergraduate classes still, and I like Anslyn and Dougherty’s “Modern Physical Organic Chemistry” for that subject.
and from Paul:
Excimer mentions my two favorite undergraduate organic texts. I would also consider ordering the solutions manual to Jones, then working out some of the problems. There are few things more satisfying than being able to solve problems to convince yourself you understand what’s going on. If you’re super-excited, what about enrolling in an orgo course at a local community college? Taking courses on a subject always gives me extra motivation to learn things, since you have to stick to a schedule.
So I bought the above (the solution manual hasn’t arrived yet) and started working through Jones ‘04. Anslyn looks like something I should read after Jones. I was impressed with how different Jones is than how I remembered my first Organic text (English & Cassidy 2nd Ed. ‘56) so I managed to find a copy on the net and it arrived today. The next post will contrast the two books.
So this series will be sort of “Rip Van Winkle meets Modern Organic Chemistry”. Why should you bother reading what’s coming? Just imagine quitting grad school with what you know and spending the next 45 years reading molecular biology and biochemistry with the background you currently have (in your spare time while going to med school and practicing neurology that is). I guarantee you’d find it primitive and rather simplistic but would have no problem understanding what’s going on. So there will be tidbits here and there that you’re unlikely to find elsewhere (such as why Jones is wrong about Strychnine poisoning — I saw a case, and how the cell lets potassium inside while excluding the smaller sodium ion — if you don’t know the answer think of how you’d design a protein to do it — MacKinnon won a Nobel for it — if you can’t wait. I can assure you that no one had a clue until the structure was solved. There was a lot of handwaving about differential absorption of Na and K to proteins, and that great fudge factor that no one could calculate — the activity coefficient.
Stay tuned,
Retread
The Chemmy Award for Organic Achievement of the Year goes to:
Melanie Sanford (Michigan) for establishing that Pd(IV) intermediates are important in at least one class of catalytic C–H bond activation reactions
I had decided on the recipient of this Chemmy a long time ago but procrastinated on writing the citation. This weekend, commenter “tuna fish” mentioned that Dr. Sanford might be moving to Yale or Caltech, and while I have no idea if this is true, the comment reminded me of my fondness for her work and that now is as good a time as any to write about it.
First off, trying to “contain” the Chemmy achievement awards in the various chemical disciplines to one year (here: 2006) is going to be difficult, because cool discoveries often take time to develop and get noticed. In this case, Sanford’s C–H activation work can be traced back to 2004. It was only last year, however, that the picture became clear (at least, clear to me).
When I learned organometallic chemistry—way back in 2002—we were essentially taught never to invoke Pd(IV) intermediates in our mechanisms. Pd(IV) was simply too energetically-inaccessible to be relevant in most cases. Along these lines, I witnessed the merciless ridicule of more than one student by the teaching staff for using Pd(IV). Instead, good boys and girls used the Pd(0)/Pd(II) couple in their mechanisms.
In 2004, Sanford came along and published a simple case of catalytic, chelate-directed C–H bond oxidation:
Instead of outlining a mechanism that shuttled back and forth between Pd(0) and Pd(II), Sanford proposed a mechanism involving Pd(IV):
Naughty! Or so I thought. A subsequent study essentially extinguished all doubt that the Pd(IV) mechanism was correct. In this 2005 JACS comm., the Sanford crew hypothesized they could change the system to stabilize the Pd(IV) intermediate, found they could actually isolate it, got a crystal structure showing that it was indeed a Pd(IV) species, and then showed that heating it gave the same types of products that they saw in reactions where the intermediate could not be isolated. Crystal structures are the closest thing we can get to having incontrovertible photographic evidence of what molecules are actually doing, so you can’t really argue this one. Score one for Pd(IV).
I know a lot of the hardcore synthesis crowd isn’t enamored with this sort of C–H activation chemistry because it is chelate-directed, which limits the scope of the reaction. That’s true, but what makes this batch of work so interesting is not the synthetic utility as much as the scientific value. We gained a new appreciation for the mechanism at play in these reactions and had to reassess a long-held notion of what isn’t reasonable.
So, congratulations to Dr. Sanford and coworkers. Enjoy your Chemmy and keep the good work coming. And if any of you donkeys out there thinks there was someone else more deserving of this award, feel free to register chemmeow.com and start your own damn blog.
Princeton University took home the Chemmy for Outstanding Department of 2006, and it looks like they’re going to make a run at defending the title in 2007. Valued sources recently told the ChemBark News Network that the Ivy League school has made generous offers to a number of outstanding young organic chemists who are already tenured in top-five departments. Fresh on the heels of adding Sorensen and MacMillan, Princeton is looking to firmly establish itself as a hotbed of organic chemistry for years to come.
Raiding other schools’ faculties has long been a strategy for building departmental strength. Where the Yankees and Red Sox are the baseball teams most willing to reach deep into their pockets for big-name talent, Harvard is the school most famous for doing so in chemistry. Most of the department’s big guns were hired as tenured professors from other schools: Corey and Jacobsen from Illinois, Whitesides from MIT, Evans and Myers from Caltech, Lieber from Columbia, Schreiber from Yale, and Kahne from Princeton. On the flip side, assistant professors have had a miserable record of gaining tenure in the department (until recently).
While pursuing the free agent market at the expense of decimating your farm system is generally a poor idea in baseball, it is a viable strategy in the world of chemistry. Granting someone tenure equates to giving them a contract for life, something unheard of in the sports world. Unfortunately for universities, it often takes more than seven years to get a handle on the quality of an assistant professor. Hiring a proven forty-year-old is a much safer bet. And unlike in sports, there are no salary caps or luxury taxes in academia, so there are no limits to the amount of money you can spend.
Of course, the strategy of buying talent is contingent on being rich—the more money a school has, the better it can play the game. Schools with less funding not only have a harder time reeling in heavy hitters, they have a harder time retaining members of their faculty who’ve attracted the interest of other schools. Money doesn’t just factor into salary, but also into expanding lab space and improving instrumentation. Ambitious professors want to improve the efficiency of their research and have the flexibility to expand their labs and their programs.
There are some factors that money can’t help. Geographic location is often important, as it influences features such as the local culture and the employment market for professors’ significant others. And as with anything related to academia, politics can play a big role. If the deans at a school get on an interdisciplinary kick, there many be money available for a nanobiophysical chemist but not for a synthetic one. An aspect that is particularly intriguing about the Princeton move is that it is geared towards pure chemistry instead of the interdisciplinary flavor of the month. That’s rare nowadays.
Of course, this story is still developing and nothing has been set in stone, but things are looking mighty exciting if you’re an organic chemist at Princeton.
I hope you enjoyed the April Fools’ Day funnay. After two days, it was clear that I could never match the Milkshake in my synthetic preps. That’s why I’ve decided to rip off Carbon-Based Curiosities instead. Let the posting of pretty pictures begin!
This may come as a surprise to you, but I have no idea what goes into making a good picture. I have a spiffy Kodak EasyShare CX7430 that is point and shoot, and that’s basically all I do. I hold photoshoots where I ask flasks to pose for twenty or so tasteful shots, then I pick the best one for the site. Is there anything more to keep in mind? Have you any pointers? Well…have you?
That yellow solid was cooked up this weekend at ChemBark Labs. Brilliant, school-bus lemon yellow. It’s probably the purdiest compound I’ve ever made, and the first time I made it I had no idea it’d even turn out colored. It’s actually research related, so please don’t try to guess what it is. I’d have to hunt down and kill any correct guessers, and I simply don’t have the time right now.
Since I happened to be taking pictures today, it’s as good a time as any to point out the coolest feature of my desk:
See it? Look closely:
Yes, it is Jesus! Or maybe just a nasty chemical stain? Well, I like to think it’s Jesus and that he’s watching out for me. Sometimes he talks. He says things like, “Get back to work” and “I wonder what that potassium cyanide tastes like.” I usually try to ignore him, but it’s hard sometimes.
As it currently stands, ChemBark is an unpopular site with no chance of ever being respected by the chemical community. The time is ripe for change. As a result, we have decided to rip off the best blog in all of chemistry: Org Prep Daily. Expect posts on synthetic procedures, lab dos and don’ts, and tips on how to get a job in pharma. We’re gonna put the Secret Milkshake out of business. Welcome to ChemBark Prep Daily!
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