Organic Letters
Letter
Notes
base. Unequal D-distribution between the diastereotopic hydro-
gens could be reasoned that steric hindrance rendered by the aryl
ring present at the β-position. Later, the synthesized α-deuterated
2′-iodochalcone afforded 11 with 10% and 62% of Da and Db
atoms, respectively, which supports the tautomerization involved
intheprefinalstepofourproposed mechanism(Scheme8b). The
loss of D-content could be explained by the H/D exchange
between 11 and moisture present in the reaction media.18 While
the preformed diazo compound 2a′ was subjected, 3 was formed
in 41% yield which proves that reaction proceeds via diazo
intermediate (Scheme 8c). It also implies that the use of N-
tosylhydrazonesascarbeneprecursorsledtobetteryieldsthanthe
direct usage of unhandy diazo compounds, highlighting the
versatility of the protocol.
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
G.S. thanks IIT Madras (CHY/17-18/847/RFIR/GSEK). D.A.
thanks CSIR for SPMF. B.D.B. thanks SERB for NPDF.
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DEDICATION
Dedicated to Prof. S. Sankararaman on his 60th birthday.
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TheSupportingInformationisavailablefreeofchargeontheACS
Experimental procedures, characterization data for all
products, NMR spectra, and single-crystal XRD data
X-ray data for compounds 3a, 3a′, 3b, 3b′, 3x and 7a (CIF)
AUTHOR INFORMATION
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Corresponding Author
ORCID
(18) 51% of D-atom at the methylene position (37% of Da and 14% of
Db) was observed when treating 3b with 5 equiv of D2O under standard
conditions.
D
Org. Lett. XXXX, XXX, XXX−XXX