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Title: A strategy for the controllable generation of organic superbases from benchtop-stable salts
Organic superbases are a distinct class of strong base that enable numerous modern reaction applications. Despite their great synthetic potential, widespread use and study of superbases are limited by their air sensitivity and difficult preparation. To address this, we report air-stable carboxylate salts of BTPP and P2-t-Bu phosphazene superbases that, when added to solution with an epoxide, spontaneously generate freebase. These systems function as effective precatalysts and stoichiometric prereagents for superbase-promoted addition, substitution and polymerization reactions. In addition to improving the synthesis, shelf stability, handling and recycling of phosphazenes, this approach enables precise regulation of the rate of base generation in situ. The activation strategy effectively mimics manual slow addition techniques, allowing for control over a reaction's rate or induction period and improvement of reactions that require strong base but are also sensitive to its presence, such as Pd-catalyzed coupling reactions.  more » « less
Award ID(s):
1944478
PAR ID:
10575300
Author(s) / Creator(s):
; ;
Publisher / Repository:
Chemical Science
Date Published:
Journal Name:
Chemical Science
Volume:
15
Issue:
26
ISSN:
2041-6520
Page Range / eLocation ID:
10018 to 10026
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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