Asymmetric Synthesis of Allylic Fluorides via Fluorination of Racemic Allylic Trichloroacetimidates Catalyzed by a Chiral Diene-Iridium Complex
作者:Jason C. Mixdorf、Alexandre M. Sorlin、Qi Zhang、Hien M. Nguyen
DOI:10.1021/acscatal.7b03786
日期:2018.2.2
The ability to use racemic allylic trichloroacetimidates as competent electrophiles in a chiral bicyclo[3.3.0]octadiene-ligated iridium-catalyzed asymmetric fluorination with Et3N·3HF is described. The methodology represents an effective route to prepare a wide variety of α-linear, α-branching, and β-heteroatom substituted allylic fluorides in good yields, excellent branched-to-linear ratios, and high
Direct Access to β-Fluorinated Aldehydes by Nitrite-Modified Wacker Oxidation
作者:Crystal K. Chu、Daniel T. Ziegler、Brian Carr、Zachary K. Wickens、Robert H. Grubbs
DOI:10.1002/anie.201603424
日期:2016.7.11
An aldehyde‐selective Wacker‐type oxidation of allylic fluorides proceeds with a nitrite catalyst. The method represents a direct route to prepare β‐fluorinated aldehydes. Allylic fluorides bearing a variety of functional groups are transformed in high yield and very high regioselectivity. Additionally, the unpurified aldehyde products serve as versatile intermediates, thus enabling access to a diverse
Iridium-Catalyzed Enantioselective Fluorination of Racemic, Secondary Allylic Trichloroacetimidates
作者:Qi Zhang、David P. Stockdale、Jason C. Mixdorf、Joseph J. Topczewski、Hien M. Nguyen
DOI:10.1021/jacs.5b07492
日期:2015.9.23
The Ir-catalyzed enantioselective fluorination of racemic, branched allylic trichloroacetiinidates with Et3N center dot 3HF is a mild and efficient route for selective incorporation of fluoride ion into allylic systems. We herein describe the asymmetric fluorination of racemic, secondary allylic electrophiles with Et3N center dot 3HF using a chiral-diene-ligated Ir complex. The methodology enables the formation of acyclic fluorine-containing compounds in good yields with excellent levels of asymmetric induction and overcomes the limitations previously associated with the eiiantioselective construction of secondary allylic fluorides bearing alpha-linear substituents.
Iridium-Catalyzed Allylic Fluorination of Trichloroacetimidates
作者:Joseph J. Topczewski、Timothy J. Tewson、Hien M. Nguyen
DOI:10.1021/ja2087213
日期:2011.12.7
allylic fluorination method utilizing trichloroacetimidates in conjunction with an iridium catalyst has been developed. The reaction is conducted at room temperature under ambient air and relies on Et(3)N·3HF reagent to provide branched allylic fluorides with complete regioselectivity. This high-yielding reaction can be conducted on a multigram scale and shows considerable functional group tolerance
Iridium-Catalyzed Radiosynthesis of Branched Allylic [<sup>18</sup>F]Fluorides
作者:Jason C. Mixdorf、Alexandre M. Sorlin、David W. Dick、Hien M. Nguyen
DOI:10.1021/acs.orglett.8b03496
日期:2019.1.4
The rapid and operationally simple radiosynthesis of branched allylic [18F]fluorides bearing a variety of functional groups, via iridium-catalyzed nucleophilic substitution reaction utilizing allylic trichloroacetimidates and [18F]KF·Kryptofix[2.2.2] complex in 5-15 min at room temperature, is reported. The versatility of the allyl functional group of the resulting radiofluorinated products offers