Sn2 Stereochemistry

Sn2 Stereochemistry

[@Frando87]

Thank you is not enough to demonstrate my absolute appreciation for your teaching.... I have been watching you for 4.5 years now and you have gotten me so far for a person that had no idea about chemistry to a person that hopefully in the near future dedicate their life to medicinal chemistry. so thank you thank you thank you thank you sooooo much I appreciate your dedication to teaching students like me.

[@BareClause]

Glad to help.

[@Pete-da-peter]

hey. just curious, what are you?

[@codchemistryclub4358]

Switching R & S configuration is not guaranteed with inversion of stereochemistry because you are substituting groups of varying priority. R/S is all 4 groups in relation to one another, you can definitely have inversion without a change of R to S. Our professor specifically cautioned not to rely on R/S for this reason.

[@lovethatnerd]

My text book does not give basic enough explanations for an organic 1 student to easily understand, so your videos are a God send for this tragically confused student. I have learned so much more from just a few of these videos than I feel like I have from almost a semester's worth of lectures and homework...

[@thenicolochy]

I'd just like to say THANK YOU for these videos! It makes me learn substitution reactions better.

[@jamesmori4887]

After SN2 occurs at a chiral carbon, I'm pretty sure the R/S configuration will only change if the nucleophile is the same priority as the leaving group. However, if you consider an H- nucleophile in an SN2 reaction, you will have inversion of configuration but it would not necessarily change R to S or S to R.

[@codchemistryclub4358]

James Mori that is correct!

[@Shadowbloodzzz]

thank you so much for what you do, I watch all your videos as im taking organic 1. they help so much!

[@Zlopras]

incredible vieods, all of them. so far I'm learning biochemistry and organic chemistry thanks to you

[@sircharles9715]

aprotic vs protic is explained in lamens terms. greatly appreciated.

[@setboy1]

@saldana787 Nope. The lowest atomic number needs to be in the back on the dotted line. when the H *isn't* in the back you need to change it from R to s or S to R

[@saldana787]

i though since the H was in the back the R becomes S, and S becomes R. ???

[@nbhmni]

Thank you so much!

[@Transpacity]

Hey Sal, do you have a vid on SN1 Stereochem? Thanks : )

[@alvarovaldivia5813]

Every time I’m trying to look the reactions up there comes the transfer of an electron pair but you’re showing it with only one electron. Is this a simplification or why is there only 1 electron in the transfers and not an electron pair?

[@Phagocytosis]

I agree completely. As for the speed, you might do what I do and watch the videos at 1.5x or 2x speed with the HTML5 trial for RUclips.

[@curtpiazza1688]

Great! 😊

[@FlyingAngel111]

Awesome.

[@Haneburge]

my only question is why did the oh go on to the side it went onto, because if it was on the other side, the designation would be R

[@GenericYoutubeNameOk]

Why am I paying for university courses when this is 100x better? : /
Thank you Sal!

[@mbsteel]

This video needs a correction. In your example, the handedness of the molecule changes due to the reactants that you chose. If the nucleophile ranks differently within the atomic weight scheme, then the handedness might not have changed even though the new functional group is now on the alternate side as the old one.

[@nipunramani]

So to generalize it, if the attacking reagents atomic number is > than the leaving group, we can say that the stereochemistry will be reversed otherwise it will be the same.

[@harshitaagnihotri7613]

Nice explanation...

[@KADMKMEOW]

You mean we're going to have THIS SITUATION?! *fl-abs*

[@FatimaKhazaal534]

Thank you 😊

[@namratakadam8007]

Why does halogen bond to that carbon only
Why not the neighbouring secondary carbon atom

[@Haneburge]

Oh ok, thank you

[@KIINZEY]

What you are doing deserves recognition. These demonstrations may very well be the best explanations that I have ever found.
Your word choices are impeccable. It would be nice to see things speed up a bit at times, but that is a very minor thing when you consider how well put together these vids are.
I will be sure to direct everyone I can to these vids. If you don't have a youtube partnership yet, hang in there, these will become a big deal soon enough.

[@Transpacity]

The configuration always flips but not necessarily the R/S

[@matthewyoungsoonam]

if they give you a formula (s)-2 Chloropentane.. and you're supposed to draw it out, how are you supposed to know if the Cl is in the front or back???

[@jinwookim8777]

+Matthew Nam You will draw CHLORINE in the front. Like Sal says, when you draw chiral molecule, you want to put HYDROGEN (lowest atomic number) in the back. Since CHLORINE is placed in 2nd carbon position, you will draw PROPYL (CH2CH2CH3) towards a side. Otherwise, if you draw PROPYL to project towards the front, it will change stereochemistry to be (R)etus instead of (S)inister.

[@ayahh2530]

does this happen to all Sn2 reactions?

[@TheBrickCraftsman]

only with a chiral carbon present like in the case of the video.

[@armenabagyan16]

because SN2 reactions are always backside attack

[@anandchainani2]

Hey Sal can u please make video on ligands. please please please

[@s0m0c]

Gracias.

[@sarthaksharma9322]

Hey Sal , but why it actually flips , is it for stability reasons ?

[@MrDeathartisan]

Not really; the flipping of the substrate's chiral configuration makes more sense if you are able to see the transition state (which is planar) between the two steps. It's rather like an umbrella flipping inside-out in the wind. Consider also that the point on the chiral carbon to which the nucleophile binds would violate tetrahedral bond angles if the other substituents (save the leaving group) were to remain in the orientations shown in step one of the reaction. They don't violate these bond angles, however, for once the leaving group has left, they reorient themselves so as to adopt the proper geometry.

[@sarthaksharma9322]

Alec Huber ok now I realize what's going on , so to preserve the stable tetrahedral geometry they flip and reorient theme selves right?

[@MrDeathartisan]

Mhmm, pretty much.

[@sophiastyles6593]

Hi will you reply to any of our question if we have one?

[@raanoooshh9296]

I doubt so

[@MathsiPhy]

Wrong . Range is R or S not guaranteed

[@achintyasharma1286]

YOU WROTE THE R AND S CONFIGURATION WRONG PLS CORRECT

[@amanialhmdani6547]

The video turns to green ( not clear)

[@ataraxia2011]

Since the alpha carbon of the substrate in this example is secondary, and OH- is both a strong base and a strong nucleophile, this reaction would actually tend to proceed via E2 and not Sn2...

[@nihayaturrohmah4230]

#30