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Title: Mechanistic Investigations of the Pd‐Catalyzed Hydrogenolysis of Ketene Heterodimer β‐Lactones

Catalytic hydrogenolysis of theZ‐isomer of a series of aryl‐substituted ketene heterodimer β‐lactones facilitated access to deoxypropionate derivatives with adrranging from 54:46 to 86:14, favoring theanti‐isomer, and with excellent transfer of chirality (91 → 99 %eefor 13 examples). Although X = 4‐F was determined to provide optimal diastereoselectivity (dr86:14), a non‐linear relationship between diastereoselectivity and aryl substituentσvalues was found. For cases where apara‐ orortho‐EWG was present on the aryl ring of the ketene heterodimer, formation of significant amounts of β‐lactone (20–44 %) as by‐product was observed. The results of a number of control reactions point toanti‐β‐elimination and ananti‐selective hydrogenation of anE‐isomer olefin intermediate being key steps in the reaction mechanism. The synthetic potential of the deoxypropionate derivative products was demonstrated by oxidative conversion into a 1,5‐difunctionalized deoxypropionate motif.

 
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NSF-PAR ID:
10238200
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
European Journal of Organic Chemistry
Volume:
2020
Issue:
35
ISSN:
1434-193X
Page Range / eLocation ID:
p. 5752-5764
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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