Mitsunobu reaction, derivatization reactions

A novel route for the synthesis of piperazin-2-ones on a solid support relies on an intramolecular Mitsunobu reaction [111]. First, commercially available amino alcohols are attached to an aldehyde resin by reductive ami-nation. The alcohol function is protected and the secondary amine obtained is acylated with an amino add. Sulfonamide activation of the free amino group allows intramolecular alkylation through a Mitsunobu reaction, and thereby the formation of a derivatized ring. 

Wu R, Odom JD, Dunlap RB, Silks LA. Reaction of alcohols (via the Mitsunobu reaction) and alkyl halides with chiral selone derivatizing agents. Tetrahedron Asymm. 1999 10 1465-1470. 

The reaction sequence starts by anchoring 2,6-dichloropurine onto the sohd-phase PAT, -amine at the more reactive C6 position with exclusive regioselectivity. A multitude of PAL-amine resins 59 can be prepared ahead by reductive amination of commercial (4-formyl-3,5-dimethoxyphe-noxy)-methylpolystyrene. The N9 position of the purine (60) may be modified by Mitsunobu alkylation. The final derivatization step involves a palladium-catalyzed cross-coupling reaction in position 2. This reaction... 

Secondary Amines. Alcohols react with this compound in THF under Mitsunobu conditions to give derivatized secondary amines. The reaction proceeds with inversion of configuration... 

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