Direct and Chemoselective Synthesis of Tertiary Difluoroketones via Weinreb Amide Homologation with a CHF<sub>2</sub>-Carbene Equivalent
作者:Margherita Miele、Andrea Citarella、Nicola Micale、Wolfgang Holzer、Vittorio Pace
DOI:10.1021/acs.orglett.9b03024
日期:2019.10.18
Weinreb amides into difluoromethylketones with a formal nucleophilic CHF2 transfer agent is reported. Activating TMSCHF2 with potassium tert-amylate enables a convenient access to the difluorinated homologation reagent, which adds to the acylating partners. The high chemoselectivity showcased in the presence of variously multifunctionalized Weinreb amides, jointly with uniformly high yields, enables the
Catalytic Enantioselective Synthesis of Highly Functionalized Difluoromethylated Cyclopropanes
作者:Maxence Bos、Wei-Sheng Huang、Thomas Poisson、Xavier Pannecoucke、André B. Charette、Philippe Jubault
DOI:10.1002/anie.201707375
日期:2017.10.16
The first catalyticasymmetricsynthesis of highly functionalized difluoromethylated cyclopropanes is described. The method, based on a rhodium‐catalyzed cyclopropanation of difluoromethylated olefins, gives access to a broad range of cyclopropanes bearing ester, ketone, or nitro functional groups. By using Rh2((S)‐BTPCP)4 as a catalyst, the corresponding products were obtained in high yields and high
Asymmetric Synthesis of Chiral
<i>α</i>
‐CF
<sub>2</sub>
H Spiro[Indoline‐3,3′‐Thiophene] via Phase‐Transfer Catalyzed Sulfa‐Michael/Michael Domino Reaction
作者:Yabo Deng、Shuo Sun、Yuqiang Wang、Pengfeng Jia、Wenguang Li、Kairong Wang、Wenjin Yan
DOI:10.1002/adsc.202101320
日期:2022.2.15
An asymmetric Sulfa-Michael/Michael domino reaction of (E)-4-mercapto-2-butenoates with difluoromethyl-eneoxindoles catalyzed by a quinidine-derived ammonium salts as phase transfer catalyst has been disclosed. Under mild conditions, a broad range of CF2H-containing spiro[indoline-3,3′-thiophene]s, bearing three adjacent chiral centers including two vicinal spiro quaternary stereocenters, catalysed
已经公开了由奎尼丁衍生的铵盐作为相转移催化剂催化的( E )-4-巯基-2-丁烯酸酯与二氟甲基-烯氧吲哚的不对称磺胺-迈克尔/迈克尔多米诺反应。在温和条件下,仅由 5 mol% PTC 催化剂催化,以产率获得了范围广泛的含 CF 2 H 螺[二氢吲哚-3,3'-噻吩],具有三个相邻的手性中心,包括两个邻位螺四元立体中心75-98%,出色的非对映选择性(在几乎所有情况下 > 20:1)和 19-98% 的对映选择性在较短的反应时间内(几乎不到 20 分钟)。
Transaminases as suitable catalysts for the synthesis of enantiopure β,β-difluoroamines
作者:Marina García-Ramos、Iván Lavandera
DOI:10.1039/d1ob02346b
日期:——
Transaminases have shown the ability to catalyze the amination of a series of aliphatic and (hetero)aromatic α,α-difluorinated ketones with high stereoselectivity, thus providing the corresponding β,β-difluoroamines in high isolated yields (55–82%) and excellent enantiomeric excess (>99%). It was also observed that these activated substrates could be quantitatively transformed by employing a small