tag:blogger.com,1999:blog-43871000093413582842012-01-27T23:52:34.955+01:00This blog is devoted to the discussion of all aspects of synthetic organic chemistry and related sciences. Curly Arrow is run by a synthetic organic chemist based in Copenhagen, Denmark. Contributions from readers are always welcome and should be emailed to curlyarrow@gmail.comDaniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.comBlogger114125tag:blogger.com,1999:blog-4387100009341358284.post-28875247801799845972011-12-27T16:25:00.001+01:002011-12-28T08:35:40.046+01:002011-12-28T08:35:40.046+01:00

Merry Christmas and Happy New Year! I Hope that everyone is getting some well-deserved time off. I used to do a yearly post on visitor stats around the blogs birthday but forgot this year!. Since it was the 5th birthday on 18th October 2011 I have decided to have a look back at how things developed in the past year. --- From 18th October 2010 to 18th October 2011: Absolute unique visitors: 

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com0http://curlyarrow.blogspot.com/2011/12/curly-arrow-established-18th-october.htmltag:blogger.com,1999:blog-4387100009341358284.post-46354679983133661702011-11-21T22:23:00.010+01:002011-11-21T23:41:44.189+01:002011-11-21T23:41:44.189+01:00

The iodine stain is by far the easiest stain to prepare and use. The classic way is to simply have a chamber with some iodine crystals that you put your TLC plate into. The iodine vapours will react with many functional groups but is particularly good with unsaturated compounds (e.g. alkenes and alkynes) to give reddish brown spots (see TLC plate below). Another way to prepare the iodine stain is

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com9http://curlyarrow.blogspot.com/2011/11/lets-talk-about-tlcs-part-5-iodine.htmltag:blogger.com,1999:blog-4387100009341358284.post-59813708586413541052011-11-15T11:22:00.018+01:002011-11-16T23:38:59.351+01:002011-11-16T23:38:59.351+01:00

I'm sure that all the synthetic organic chemists will agree that column chromatography is something we simply couldn't live without. At our Department we use it in all its forms: Automated flash chromatography, Chromatotron, Prep. HPLC (Chiral and RP), Prep. TLC, old skool manual flash and DCVC columns etc. However, in spite of all this we all too frequently end up with stuff that is a major

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com21http://curlyarrow.blogspot.com/2011/11/reverse-phase-silica-sort-of.htmltag:blogger.com,1999:blog-4387100009341358284.post-55184907721718139502011-04-18T15:43:00.006+02:002011-04-18T16:00:22.217+02:002011-04-18T16:00:22.217+02:00

Self Promotion time! Our review on 1,2,3-Triazoles in Peptidomimetic Chemistry was just published in EuroJOC.Useful stuff if you are working in the peptidomimetic area. You can get it here or by emailing curlyarrow@gmail.com. D!

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com3http://curlyarrow.blogspot.com/2011/04/triazoles-in-peptidomimetic-chemistry.htmltag:blogger.com,1999:blog-4387100009341358284.post-91746884921497916632011-03-08T21:58:00.008+01:002011-03-08T22:38:45.794+01:002011-03-08T22:38:45.794+01:00

Yes, I am still alive! I have been out of the lab for a loooong time so the inspiration hasn't been there. However, I am now finding myself in the lab again and it appears that I will get to stay there for a while. And today inspiration struck.Let's talk about oil baths. Good way to heat stuff up in a controlled way, BUT, what a bloody mess they are. The oil becomes disgusting after a while, the

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com9http://curlyarrow.blogspot.com/2011/03/sand-bath-alternative-to-oil-bath.htmltag:blogger.com,1999:blog-4387100009341358284.post-90102962805603288882010-10-27T13:50:00.005+02:002010-10-27T14:11:20.790+02:002010-10-27T14:11:20.790+02:00

I have copy/pasted the headline for this post from the editorial in the most recent issue of Organic Process Research and Development. It's a good question that is being asked and I believe that the answer is YES. However, we really need to come up with something new to justify our existence. The Chinese and others are just as good as us at doing Med Chem SAR working their way through methyl,

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com8http://curlyarrow.blogspot.com/2010/10/is-there-future-for-organic-chemists-in.htmltag:blogger.com,1999:blog-4387100009341358284.post-87920207875628799112010-10-08T22:56:00.006+02:002010-10-08T23:18:10.908+02:002010-10-08T23:18:10.908+02:00

I'm currently in Brussels vistiting a collaborator. The research groups lab is absolutely fascinating and contains several old school mechanical contraptions that do a great job.For your glassware drying pleasures:For melting point determination (not sure how useful this device is but its looks cool):It's not always necessary to upgrade to an expensive model with digitals controls to achieve the

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com4http://curlyarrow.blogspot.com/2010/10/if-it-works-dont-mess-with-it.htmltag:blogger.com,1999:blog-4387100009341358284.post-75035854637800748742010-09-01T10:07:00.006+02:002010-09-01T10:13:00.621+02:002010-09-01T10:13:00.621+02:00

If you didn't already spot this useful paper on NMR impurities you should go get it now. An excellent addition to the classic paper by Gottlieb et al. that you can access here. D!

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com2http://curlyarrow.blogspot.com/2010/09/nmr-impurities-tabulated.htmltag:blogger.com,1999:blog-4387100009341358284.post-3726902327851370912010-07-16T13:24:00.011+02:002010-07-16T13:37:27.030+02:002010-07-16T13:37:27.030+02:00

Design and synthesis of the first selective ligands for the GPRC6A receptor – a novel human G-protein coupled receptor with unknown physiological functionMore info at this web site.DO NOT email us but please follow the application procedure at the bottom of this web page.There are links to all necessary information on the same web page.D!

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com1http://curlyarrow.blogspot.com/2010/07/phd-in-medicinal-chemistry.htmltag:blogger.com,1999:blog-4387100009341358284.post-32483327686808165052010-06-22T21:27:00.003+02:002010-06-23T09:40:54.282+02:002010-06-23T09:40:54.282+02:00

This is what 40 g of the depicted indole looks like after one recrystallisation. It really shouldn't be green but it is very pretty and even better it's analytically pure. D!Okay, okay people. Is the photo more to your satisfaction? D!

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com11http://curlyarrow.blogspot.com/2010/06/green.htmltag:blogger.com,1999:blog-4387100009341358284.post-40109943376452321372010-04-24T13:52:00.006+02:002010-04-24T14:02:12.638+02:002010-04-24T14:02:12.638+02:00

Wow, I just realised that I've passed the 100 posts mark a while back.-The Coffee Break section has been updated with a new comic website called The Perry Bible Fellowship. Fantastic stuff that you really should check out. Also there's been a fair bit of activity at Electra Lady Land so that's worth a visit if your into the arty stuff. D!

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com3http://curlyarrow.blogspot.com/2010/04/100th-anniversary.htmltag:blogger.com,1999:blog-4387100009341358284.post-64212729810597786912010-04-24T12:15:00.012+02:002010-04-24T13:43:15.216+02:002010-04-24T13:43:15.216+02:00

I have discussed anhydrous solvents a couple of times and have been advertising the use of molecular sieves (MS) quite strongly. During my MS crusade I have pointed out that MS are no good for drying THF but that pretty much all other standard solvents work well with sieves. As it turns out this is incorrect and I have received a terrible punishment from the MS God. It's all rather embarrassing

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com6http://curlyarrow.blogspot.com/2010/04/anhydrous-solvents-part-3-acetone-and.htmltag:blogger.com,1999:blog-4387100009341358284.post-78041675755939569952010-04-13T17:00:00.004+02:002010-04-13T17:03:22.045+02:002010-04-13T17:03:22.045+02:00

There's some seriously hard science in the latest issue of ChemComm. D!

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com4http://curlyarrow.blogspot.com/2010/04/hard-science.htmltag:blogger.com,1999:blog-4387100009341358284.post-75799653226647287822010-03-31T22:34:00.001+02:002010-03-31T22:35:01.993+02:002010-03-31T22:35:01.993+02:00

I do apologies for the very infrequent posting. I seem to have developed a life with other areas of interest than chemistry. However, due to the many old posts that people find useful the blog gets around 150 unique visitors every day (Including Nobel Laureates!!! Can you guess who?) so I'll keep Curly Arrow running at a gentle simmer.---Returning to catalytic hydrogenation, as promised:

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com9http://curlyarrow.blogspot.com/2010/03/catalytic-hydrogenation-part-iii-more.htmltag:blogger.com,1999:blog-4387100009341358284.post-77612999425185297682010-01-25T10:16:00.027+01:002010-01-28T15:38:55.679+01:002010-01-28T15:38:55.679+01:00

Well since I appear to be suffering from insomnia I may as well blog a bit. It's about time anyway.All synthetic organic chemists will eventually be facing a catalytic hydrogenation. Catalytic hydrogenations are great because they are easy to perform, generally work well and it allows you to do a fair bit of rather useful chemistry. But remember not to set them on fire.I have helped many chemists

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com11http://curlyarrow.blogspot.com/2010/01/catalytic-hydrogenation-part-ii-tips.htmltag:blogger.com,1999:blog-4387100009341358284.post-86015141325269893772009-12-22T22:22:00.000+01:002009-12-22T22:22:34.032+01:002009-12-22T22:22:34.032+01:00

Christmas is approaching rapidly and I am off from work until 4th January. I will try my very, very best to do nothing work related for the next 2 weeks (Could be tricky. Fingers crossed)---This years Christmas post is a tribute to Robert Robinson for inventing the curly arrow. It really is fascinating to think how recently we have have come to think about molecules the way we do now. The whole

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com1http://curlyarrow.blogspot.com/2009/06/th-history-of-curly-arrows.htmltag:blogger.com,1999:blog-4387100009341358284.post-51182307692977644732009-12-09T10:52:00.003+01:002009-12-09T10:56:33.478+01:002009-12-09T10:56:33.478+01:00

Yesterday one of the PhD students was having a bit of fun iodinating with Iodine monochloride. D!

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com2http://curlyarrow.blogspot.com/2009/12/colour-of-chemistry-part-ii.htmltag:blogger.com,1999:blog-4387100009341358284.post-7496898761040269592009-11-29T21:00:00.003+01:002009-11-29T21:07:35.318+01:002009-11-29T21:07:35.318+01:00

As a synthetic organic chemist what I would like at the end of the day are some white or colourless crystals. However, off-white, tan or yellow amorphous solid is more or less what you expect to end up with. But when I get bright pink, purple and green stuff I really don't know what to make of it. D!

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com11http://curlyarrow.blogspot.com/2009/11/colour-of-organic-chemistry.htmltag:blogger.com,1999:blog-4387100009341358284.post-43164800561250312662009-10-21T20:48:00.004+02:002009-10-21T22:33:45.674+02:002009-10-21T22:33:45.674+02:00

Old school 1,4-butynediol. A wondeful and cheap building block. D!

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com4http://curlyarrow.blogspot.com/2009/10/butt-in-diol.htmltag:blogger.com,1999:blog-4387100009341358284.post-24637050492529173362009-10-18T17:30:00.002+02:002011-12-27T16:04:53.373+01:002011-12-27T16:04:53.373+01:00

Three years later. I'm surprised that I still manage to keep Curly Arrow alive. The reason that things are still happening is you guys that read my stuff and send me some very positive and enthusiastic emails. I'm getting a lot of hits from Google and the blog appears to have a tremendous impact. For example if you do a Google search on Click Chemistry you'll see the Wikipedia entry as the top

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com4http://curlyarrow.blogspot.com/2009/10/curly-arrow-established-18th-october.htmltag:blogger.com,1999:blog-4387100009341358284.post-90212626329335218922009-10-06T18:00:00.004+02:002009-10-06T19:25:21.937+02:002009-10-06T19:25:21.937+02:00

Leaving group activation of alcohols followed by nucleophilic substitution is routine stuff for the synthetic organic chemist. Just make the tosylate, nosylate, mesylate, triflate.... and things generally go according to plan. However, what if you are stuck with an amine and want to substitute it with a nucleophile. There are a number of ways to do this but it's not just a walk in the park.

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com16http://curlyarrow.blogspot.com/2009/09/how-to-turn-amine-into-leaving-group.htmltag:blogger.com,1999:blog-4387100009341358284.post-62682943782498286952009-10-03T12:55:00.008+02:002009-10-03T13:22:17.420+02:002009-10-03T13:22:17.420+02:00

I have previosuly been moaning about the fear of stereogenic centers that industry seems to suffer from here. So it was with great pleasure that I read Derek Lowe's latest contribution to Chemistry World were he appears to share some of my views.Derek Lowe is a medicinal chemist running the hugely succesfull blog In the Pipeline. If you don't already frequent this blog you should get started. He

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com2http://curlyarrow.blogspot.com/2009/10/stereogenofobia.htmltag:blogger.com,1999:blog-4387100009341358284.post-47635287237056070212009-10-01T23:01:00.004+02:002009-10-01T23:22:42.849+02:002009-10-01T23:22:42.849+02:00

I keep thinking that I'm all done paper pushing and then somehow magically I'm back at it full force. So recently I've submitted four grant proposals, written a chapter for a book, started teaching again and in parallel I'm doing a half hearted attempt at some lab work. So the last thing I needed to see was this paper Don't read that paper if you are a suicidal post doc.I guess it's the life I've

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com5http://curlyarrow.blogspot.com/2009/10/making-cut.htmltag:blogger.com,1999:blog-4387100009341358284.post-42139816184189383422009-07-28T21:16:00.001+02:002009-07-28T21:43:41.412+02:002009-07-28T21:43:41.412+02:00

After this rather interesting paper on the oxidation powers of sodium hydride (That has been slapped around by the blogging community in a big way) it seems appropriate with a post on reagents that actually are capable of performing oxidations.---We all know pydridinium dichromate (PDC). It's one of these hopeless reagents that still gets taught on undergraduate chemistry courses despite the fact

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com12http://curlyarrow.blogspot.com/2009/07/tpap-vs-pdc.htmltag:blogger.com,1999:blog-4387100009341358284.post-89033534636701468382009-07-24T12:47:00.005+02:002009-07-24T17:41:46.038+02:002009-07-24T17:41:46.038+02:00

I'm having coffee and missed having some some Curly Arrow links to fun stuff. So a list of links has been added (bottom right on the front page). Chemical Stick Figures and xkcd are personal favourites. Also Org Prep Daily has started posting again and so has been upgraded from a chemistry resource to a blog.Have a nice weekend, D!

Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.com0http://curlyarrow.blogspot.com/2009/07/coffee-break.html