Electrophilic halogenation is used to produce a wide variety of halogenated compounds. Previously reported methods have been developed mainly using a reagent‐based approach. Unfortunately, a suitable “catalytic” process for halogen transfer reactions has yet to be achieved. In this study, arylamines have been found to generate an N‐halo arylamine intermediate, which acts as a highly reactive but selective catalytic
Chemodivergent, Tunable, and Selective Iodine(III)-Mediated Bromo-Functionalizations of Polyprenoids
作者:Tatyana D. Grayfer、Pascal Retailleau、Robert H. Dodd、Joëlle Dubois、Kevin Cariou
DOI:10.1021/acs.orglett.7b02125
日期:2017.9.15
Mild oxidation of bromides by iodine(III) reagents generated active electrophilic bromination species that were reacted with polyprenoids. By simple and minor variations of an I(III)/Br combination, the reactivity could be selectively steered toward dibromination, oxybromination, or bromocyclization, giving access to a wide array of brominated motifs.
The first catalyticasymmetric bromonium ion-induced polyene cyclization has been achieved by using a chiral BINOL-derived thiophosphoramide catalyst and 1,3-dibromo-5,5-dimethylhydantoin as an electrophilic bromine source. Bromocyclization products are obtained in high yields, with good enantiomeric ratios and high diastereoselectivity, and are abundantly found as scaffolds in natural products.
UNIQUE HALOGEN-INDUCED CYCLIZATIONS, REAGENTS THEREFOR, AND COMPOUNDS PRODUCED THEREBY
申请人:Snyder Scott Alan
公开号:US20140243404A1
公开(公告)日:2014-08-28
This disclosure is related to halonium compounds useful for cyclization of polyenes, alkenoic acids, and alkenyl alkyl ethers, and halogenation of aromatic compounds. The synthesis of such halonium compounds, compounds made using such halonium compounds, and synthesis of natural compounds, including decalins, using the halonium compounds is also disclosed. A representative halonium compound of the disclosure is: