Without employing any transition metal and other additives, efficient methods for selective difluoromethylations of β-keto amides with TMSCF2Br reagent have been developed under mild conditions. This protocol allows a convenient access to various α-difluoromethyl β-keto amides with excellent yields (up to 93%) and high carbon/oxygen (C/O) regioselectivities (up to 99:1). The C/O selectivity of β-keto amides could be easily reversed and controlled by simply changing the base. This protocol can be easily scaled-up and the C-difluoromethylation product could be reduced into CF2H-containing amino alcohol derivatives. Moreover, the first enantioselective electrophilic difluoromethylation of β-keto amides has been achieved by phase-transfer catalysis.

中文翻译：

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在温和条件下用 TMSCF2Br 对 β-酮酰胺进行高选择性二氟甲基化

在不使用任何过渡金属和其他添加剂的情况下，已开发出在温和条件下使用 TMSCF2Br 试剂选择性二氟甲基化 β-酮酰胺的有效方法。该协议允许以优异的产率（高达 93%）和高碳/氧 (C/O) 区域选择性（高达 99:1）方便地获取各种 α-二氟甲基 β-酮酰胺。β-酮酰胺的 C/O 选择性可以通过简单地改变碱来轻松逆转和控制。该协议可以很容易地扩大规模，并且可以将 C-二氟甲基化产物还原为含 CF2H 的氨基醇衍生物。此外，β-酮酰胺的第一个对映选择性亲电二氟甲基化已经通过相转移催化实现。