Highly Efficient "On Water" Catalyst-Free Nucleophilic Addition Reactions Using Difluoroenoxysilanes: Dramatic Fluorine Effects

• Published in: Angewandte Chemie (International ed.) Vol. 53; no. 36; pp. 9512 - 9516
• Main Authors: Yu, Jin-Sheng, Liu, Yun-Lin, Tang, Jing, Wang, Xin, Zhou, Jian
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.09.2014; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Activated; Catalysts; Chemistry; Chemistry, Multidisciplinary; Droplets; Fluorination; Fluorine; heterocycles; heterogeneous catalysis; Ketones; Networks; Nucleophiles; Phase boundaries; Physical Sciences; Science & Technology; synthetic methods; water chemistry; MUKAIYAMA-ALDOL; DIELS-ALDER; ASYMMETRIC-SYNTHESIS; heterogeneous catalysis; ONE-POT SYNTHESIS; PROMOTED ORGANIC-REACTIONS; ACCELERATION; ALCOHOLS; heterocycles; CARBONYL; CHEMISTRY; SILYL; water chemistry; synthetic methods; fluorine
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201404432

A remarkable fluorine effect on “on water” reactions is reported. The CF⋅⋅⋅HO interactions between suitably fluorinated nucleophiles and the hydrogen‐bond network at the phase boundary of oil droplets enable the formation of a unique microstructure to facilitate on water catalyst‐free reactions, which are difficult to realize using nonfluorinated substrates. Accordingly, a highly efficient on water, catalyst‐free reaction of difluoroenoxysilanes with aldehydes, activated ketones, and isatylidene malononitriles was developed, thus leading to the highly efficient synthesis of a variety of α,α‐difluoro‐β‐hydroxy ketones and quaternary oxindoles. It's on! The CF⋅⋅⋅HO interactions between suitably fluorinated nucleophiles and a hydrogen‐bond network at the phase boundary of an oil droplet facilitate “on water” catalyst‐free reactions. Accordingly, the title reaction of difluoroenoxysilanes with aldehydes, activated ketones, and isatylidene malononitriles was developed, thus leading to α,α‐difluoro‐β‐hydroxy ketones and quaternary oxindoles.