Reversal of Regioselectivity in Nucleophilic Difluoroalkylation of α,β-Enones Employing In Situ-Formed Sterically Encumbered Silylium Catalyst
作者:Jinshan Li、Saimei Liu、Rong Zhong、Yaqi Yang、Yuru He、Jianguo Yang、Yongmin Ma、Zhiming Wang
DOI:10.1021/acs.orglett.1c01993
日期:2021.8.6
regioselectivity in the nucleophilic introduction of difluorinated carbanion into α,β-enones has been developed via a silylium catalysis. The strong electron-withdrawing properties and bulky substituents of in situ-generated silyl triflic imide catalyst is the key for the 1,4-addition reaction to proceed smoothly. The syntheticutility is highlighted by the further use of this method for the synthesis
Organocatalytic asymmetric synthesis of 3-difluoroalkyl 3-hydroxyoxindoles
作者:Yun-Lin Liu、Jian Zhou
DOI:10.1039/c2cc17140f
日期:——
We report the first example of highly enantioselective organocatalytic synthesis of 3-difluoroalkyl substituted 3-hydroxyoxindoles. The total synthesis of the difluoro analogue of convolutamydine E was achieved by this method.
Cascade Cyclization of Azadienes with Difluoroenoxysilanes: A One-Pot Formal [4 + 2] Approach to Fluorinated Polyfused Heterocycles
作者:Jinshan Li、Saimei Liu、Rong Zhong、Yaqi Yang、Jinjing Xu、Jianguo Yang、Hanfeng Ding、Zhiming Wang
DOI:10.1021/acs.orglett.1c03745
日期:2021.12.17
fluorinated polyfused heterocycles via the cascade cyclization of azadienes and difluoroenoxysilanes has been developed, leading to the facile construction of fluorinated benzofuro[3,2-b]pyridines, 5H-indeno[1,2-b]pyridines, and 5,6-dihydrobenzo[h]quinolines. This one-pot formal [4 + 2] approach involves 1,4-difluoroalkylation, desulfonylation, cyclization, and dehydrated and dehydrofluorinated aromatization
通过氮杂二烯和二氟烯氧基硅烷的级联环化,TfOH 促进了氟化多稠杂环的合成,从而轻松构建了氟化苯并呋喃[3,2- b ]吡啶、5 H-茚并[1,2- b ]吡啶, 和 5,6-二氢苯并[ h ]喹啉。这种一锅法 [4 + 2] 方法涉及 1,4-二氟烷基化、脱磺酰化、环化以及脱水和脱氟化氢芳构化,代表了二氟烯氧基硅烷在级联转化中的首次应用。此外,该方法通过合成具有强效拓扑异构酶抑制活性的生物活性分子的三种氟类似物而突出。
Divergent Synthesis of <i>gem</i>-Difluorinated Oxa-Spirocyclohexadienones by One-Pot Sequential Reactions of <i>p</i>-Hydroxybenzyl Alcohols with Difluoroenoxysilanes
作者:Haijian Wu、Peng Hong、Wenxue Xi、Jinshan Li
DOI:10.1021/acs.orglett.2c00550
日期:2022.4.8
A new efficient formal [2 + 3] cyclization of p-hydroxybenzyl alcohols with difluoroenoxysilanes has been established. This convenient one-pot sequential procedure enables the divergent construction of highly functionalized gem-difluorinated oxa-spirocyclohexadienones under mild conditions. As opposed to the common C1 synthons in previous studies, difluoroenoxysilanes acted as new 3-atom (CCO) synthons
已经建立了对羟基苯甲醇与二氟烯氧基硅烷的一种新的有效形式 [2 + 3] 环化。这种方便的一锅顺序程序能够在温和条件下不同地构建高度官能化的偕二氟化氧杂螺环己二烯酮。与之前研究中常见的 C1 合成子不同,二氟烯氧基硅烷首次在这里充当新的 3 原子 (CCO) 合成子。反应中产生的 AcOH 和 H 2 O 是反应顺利进行的关键。
Squaramide/Li<sup>+</sup>-Catalyzed Direct S<sub>N</sub>1-Type Reaction of Vinyl Triflates with Difluoroenoxysilanes through Vinyl Cations
作者:Yan Chen、Vincent Gandon、Christophe Bour
DOI:10.1021/acs.orglett.2c02793
日期:2022.9.30
Difluoromethylene-skipped enones have been readily obtained from arylvinyltriflates and aryldifluoroenoxysilanes. While these useful compounds are difficult to synthesize by the classical aldol/dehydration approach, the use of a squaramide/Li+ catalyst allows their direct formation via a vinyl carbocation paired with a weakly coordinating perfluorinated alkoxyaluminate. This strategy makes possible a reaction between