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The Coming of Age in Iodane‐Guided ortho ‐C−H Propargylation: From Insight to Synthetic Potential
Author(s) -
Izquierdo Susana,
Bouvet Sébastien,
Wu Yichen,
Molina Sonia,
Shafir Alexandr
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201804058
Subject(s) - propargyl , chemistry , electrophile , iodobenzene , combinatorial chemistry , medicinal chemistry , stereochemistry , organic chemistry , catalysis
As early as 1991 Ochiai et al. reported that an acid‐activated form of phenyliodine diacetate, PhI(OAc) 2 , undergoes a reaction with propargyl‐silanes, germanes and stannanes to give the ortho ‐propargyl iodobenzene. This formal C−H alkylation was proposed to take place through an unusual (even to date) iodonio‐based [3,3] rearrangement of an intermediate allenylsilane. Although this mechanistic principle has been invoked in related iodane‐directed C−H coupling reaction, some underlying principles have remained unaddressed, and the reaction rarely employed. Herein, DFT evidence for a mechanism best described as iodine‐guided electrophilic aromatic substitution is presented. Using a newly optimized reaction protocol that significantly reduces the undesired reduction process, the potency of the method is showcased through the synthesis of >40 structurally diverse ortho ‐iodo propargyl (or allenyl) arenes.