[CPC]

Hallo.
I have got a problem to elucidate the mechanism of the reaction described in the attached file.
Can anyone help give any suggestions, especially emphasize the role of PPh3 or P(OPh)3 herein.
I am a student who is in the first period at university so I am not really good at understanding the mechanism of the reaction, but I wish step by step to learn it from the basis of organic chemistry.
Looking forward to getting your help.
CPC

[Dan]

Conceptually, the mechanism has many similarities (in my opinion) to the Mitsunobu reaction. Perhaps take a look at that mechanism and see if you have any ideas.

[CPC]

Hi Dan.
Thank you for your suggestion. I have had a look at the mechanism of Mitsunobu reaction but still cannot figure out a proper pathway for the mechanism of the mentioned reaction which should be applied. First attempt, almost no knowledge and experience in elucidating mechanism. Can help give me the first lesson?
Appreciate very much.
CPC

[Dan]

Ok, to start you off the disulfide initially plays a similar role to DEAD in the Mitsunobu.

[CPC]

Thank you.
Phosphine more or less plays a role of a nucleophile meanwhile DEAD behaves an electrophile anyway.
How to elucidate an electrophile center from the disulfide so that the phosphine can attack?

[Dan]

Hint: The weakest bond will break: S-S

[CPC]

Thanks.
I have considered it and talked to friend here too.
I post the scheme so that we can discuss.
CPC

[Dan]

Your mechanism with PPh₃ looks good to me. I would expect the mechanism with P(OMe)₃3 to be exactly the same.

[CPC]

Yes, I think that I have postulated it the same way.
However, could you please give me a suggestion to explain the role of TEA?
Thanks.
CPC