Triflic Acid-Catalyzed Dehydrative Amination of 2-Arylethanols with Weak N-Nucleophiles in Hexafluoroisopropanol.

The catalytic deoxyamination of readily available 2-arylethanols offers an appealing, simple, and straightforward means of accessing β-(hetero)arylethylamines of biological interest. Yet, it currently represents a great challenge to synthetic chemistry. In most cases, the alcohol has to be either pre-activated in situ or converted into a reactive carbonyl intermediate, limiting the substrate scope for some methods.

A povarov-type reaction to access tetrahydroquinolines from -benzylhydroxylamines and alkenes in HFIP.

Here, we report the synthesis of tetrahydroquinolines between newly developed -benzylhydroxylamine reagents and alkenes using HFIP as a solvent. This transformation is notably applicable to highly electronically deactivated styrenes and aliphatic alkenes, expanding the range of tetrahydroquinolines attainable.

Iron(II)-Catalyzed 1,2-Diamination of Styrenes Installing a Terminal NH Group Alongside Unprotected Amines.

1,2-Diamination of alkenes represents an attractive way to generate differentiated vicinal diamines, which are prevalent motifs in biologically active compounds and catalysts. However, existing methods are usually limited in scope and produce diamines where one or both nitrogens are protected, adding synthetic steps for deprotection and further N-functionalization to reach a desired target. Furthermore, the range of amino groups that can be introduced at the internal position is fairly limited.

Difunctionalization Processes Enabled by Hexafluoroisopropanol.

In the past 5 years, hexafluoroisopropanol (HFIP) has been used as a unique solvent or additive to enable challenging transformations through substrate activation and stabilization of reactive intermediates. In this Review, we aim at describing difunctionalization processes which were unlocked when HFIP was involved. Specifically, we focus on cyclizations and additions to alkenes, alkynes, epoxides, and carbonyls that introduce a wide range of functional groups of interest.