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Lapierre, Andre Joseph Benjamin (2006) CHIRALITY TRANSFER IN 5-EXO CYCLIZATIONS OF AXIALLY CHIRAL O-IODOANILIDES. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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Stereoselective 5-exo radical and Heck cyclizations of axially chiral o-iodoanilides to enantioenriched oxindoles and dihydroindolones are described. Mechanisms for the transfer of chirality from the atropisomeric anilides to the newly formed stereocenters in the cyclic products are proposed and supported with physical data. Additionally, the N-aryl bond rotation barriers for eight o-iodoanilides are reported. A series of axially chiral N-allyl-o-iodoanilides were cyclized under room temperature radical conditions to dihydroindolones with good to excellent chirality transfer (74-97 %). Cyclization rate constant data is presented to rationalize the regioselective preference for N-allyl over N-acryloyl cyclization when an o-methyl group is present. X-ray crystallography was used to assign absolute configurations to a cyclization precursor/product pair. Radical 5-exo cyclizations of axially chiral o-iodoanilides bearing branched, bulky N-substituents are covered. The bulkiness of N-substituents permitted the resolution of a series of novel o-iodoanilides lacking a second ortho substituent. Radical cyclizations of these o-iodoanilides transferred this transient axial chirality into a new stereocenter in the oxindole products with high fidelity (78-92 %). The first Heck cyclizations of axially chiral o-iodoanilides with chirality transfer (84-89 %) are described. X-ray crystallographic data is presented for one anilide cyclization precursor with studies to elucidate the mechanism of chiral transfer.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Lapierre, Andre Joseph
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairCurran, Denniscurran@pitt.eduCURRAN
Committee MemberBrummond, Kaykbrummon@pitt.eduKBRUMMON
Committee MemberMokotoff, Michaelmoagie@pitt.eduMOAGIE
Committee MemberCohen, Theodorecohen@pitt.eduCOHEN
Date: 20 March 2006
Date Type: Completion
Defense Date: 6 December 2005
Approval Date: 20 March 2006
Submission Date: 29 November 2005
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Institution: University of Pittsburgh
Schools and Programs: Dietrich School of Arts and Sciences > Chemistry
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: 5-exo cyclization; anilides; axial chirality; chirality transfer
Other ID:, etd-11292005-113044
Date Deposited: 10 Nov 2011 20:06
Last Modified: 15 Nov 2016 13:52


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