Diastereoselective Synthesis of Cyclopentenes via RhII-Catalyzed C-H Insertion Directed by a Planar Chiral N-Oxazolidinoyl Iron(0) Tricarbonyl Diene Complex
Hejna, Benjamin G.
Herein is presented a general methodology for the synthesis of cyclopentenes
bearing two consecutive, diastereoselectively generated stereocenters by RhII-catalyzed
C-H insertion using a planar chiral N-oxazolidinoyl iron(0) tricarbonyl diene complex as
a steric directing group. The majority of this work is dedicated to designing and accessing
viable substrates to undergo the aforementioned diastereomerically selective C-H
insertion, as well as determination of the absolute stereochemical configuration of the
enantiomerically pure product. We hypothesize that the observed stereochemical outcome
is caused by the favorability of orienting the substituent on each newly-generated
stereocenter away from the sterically bulky iron(0) tricarbonyl fragment.
In addition to this methodology, a number of other methods are presented
describing the reactivity of N-oxazolidinoyl iron(0) tricarbonyl dienes, including novel
diazo transfers, mild removal of the oxazolidinone auxiliary, and diastereoselective
intramolecular cyclizations, oxidative removal of the iron(0) tricarbonyl moiety, as well
as steps towards electrochemical decomplexation.
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