[1,1'-(Azodicarbonyl)dipiperidine]
Other Names:
1,1'-Azobis(N,N-pentamethyleneformamide)
Azodicarboxylic acid dipiperidide
ADD
Structure:
CAS Number: 10465-81-3
Molecular Weight: 252.31 g/mol
Melting Point: 134-136 C
1,1-(Azodicarbonyl)dipiperidine (ADDP) is typically used as a reagent in Mitsunobu reactions. ADDP is an Azo-type reagent that enables Mitsunobu reactions with certain substrates that react poorly or fail with DEAD-TPP systems. DEAD-TPP Mitsunobu reactions generally only work well with substrates that have a pKa < 11. Azo-type reagents are more easily protonated by less acidic substrates, therefore should allow more successful reactions when substrates have a pKa near the limits of the DEAD-TPP system's abilities, which as mentioned before is at pKa ~11.
Azo-type reagents are poorer Michael acceptors than DEAD, therefore they are generally paired with more nucleophilic phosphine reagents than TPP, such as tributylphosphine or trioctylphosphine.
Reagent in Mitsunobu reactions
Procedure excerpt:
. . . was added ADDP (0.192 g, 0.761 mmol) and the mixture was again sparged with N2 and stirred an additional 10 min. Trioctylphosphine (0.40 mL, 0.81 mmol) was added . . .
1) Patent Reference: WO2016014463, page 168, (6.7 MB)
2) www.sigmaaldrich.com: 1,1’-(Azodicarbonyl)dipiperidine (link)
3) www.alfa.com: H27719 1,1’-(Azodicarbonyl)dipiperidine, 97% (link)
4) Tsunoda, Tetsuto; Kaku, Hiroto; Ito, Sho; New Mitsunobu Reagents (TCI Mail) (link)