Enantioselective Friedel–Crafts Alkylation of Furans with <i>o</i>-Quinone Methide Using a Chiral Oxazaborolidinium Ion Catalyst

Cho, Yoon Sung; Kim, Seung Tae; Ryu, Do Hyun

doi:10.1021/acs.orglett.2c00404

Cited by 14 publications

(6 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…催化不对称 Friedel-Crafts 烷基化反应是有机合成中的一类重要反应, 其中, 呋喃参与的催化不对称 Friedel-Crafts 烷基化反应非常有限, 这主要是由于呋喃自身较弱的亲核性、在酸性条件下的相对不稳定性等原因造成的 [55] . 2022 年, Ryu 课题组 [56] [57] 实现了手性磷酸催化下氧亲核试剂 106 与邻羟基苄醇 6 的不对称加成反应, 高立体选择性地实现了含氧的碳手性中心的直接构筑(Scheme 35, a). 值得注意的是, 由于 C-O 键形成过程中的可逆反应以及醇类化合物较低的反应活性, 分子间的催化不对称氧杂 Michael 加成反应具有很大的挑战性.…”

Section: 邻羟基苄醇参与的催化不对称[4＋3]环加成反应unclassified

Advances in Catalytic Asymmetric Reactions Involving o-Hydroxybenzyl Alcohols

Wang¹,

Yang²,

Zhang³

et al. 2023

Chinese Journal of Organic Chemistry

View full text Add to dashboard Cite

Ortho-quinone methides (o-QMs) belong to a class of highly reactive organic intermediates, which play an important role in catalytic asymmetric formations of carbon-carbon bond and carbon-heteroatom bond. However, o-QMs are highly unstable, which led to the underdevelopment of catalytic asymmetric reactions involving o-QMs. The utilization of some precursors for in situ generating o-QMs is a solution to address this challenging issue. Therefore, the development of catalytic asymmetric reactions involving in situ generated o-QMs has absorbed great attention from the chemists. The key to develop such reactions is to exploit easily available and stable precursors of o-QMs. Ortho-hydroxybenzyl alcohols are a kind of o-QM precursors with unique advantages. Hence, the catalytic asymmetric [4＋n] cycloadditions, tandem cyclizations and nucleophilic additions of o-hydroxybenzyl alcohols have developed very rapidly in recent years, which have become efficient strategies for the synthesis of chiral oxygen-containing heterocycles and arylmethane derivatives. The catalytic asymmetric reactions involving o-hydroxybenzyl alcohols are summarized, which will open a new window for the design of new type of o-hydroxybenzyl alcohols and their involved catalytic asymmetric reactions. Keywords o-hydroxybenzyl alcohol; o-quinone methide; asymmetric catalysis; cycloaddition; cyclization; addition 邻亚甲基苯醌(o-Quinone Methides, o-QMs)是一类具有高反应活性且易于被手性催化剂活化的有机中间体, 在碳-碳键及碳-杂原子键的催化不对称构筑中发挥着重要作用, 在有机合成、药物化学及天然产物化学等多个领域显示出良好的应用前景 [1][2][3][4][5] . 虽然早在 1907 年 Fries 等 [1a] 就首次提出了 o-QMs 中间体的概念, 但由于该类中间体非常不稳定且半衰期很短, 导致这类中间体参与的催化不对称反应在近二十年中才取得了突破性的进展 [3][4] , 至今仍是一个亟待发展的重要研究领域.发展 o-QMs 参与的催化不对称反应的关键是开发简便易得、结构稳定并易于原位转化的前体. 近年来, 随着 o-QMs 化学的快速发展, 结构多样的 o-QMs 中间

show abstract

Section: 邻羟基苄醇参与的催化不对称[4＋3]环加成反应unclassified

Advances in Catalytic Asymmetric Reactions Involving o-Hydroxybenzyl Alcohols

Wang¹,

Yang²,

Zhang³

et al. 2023

Chinese Journal of Organic Chemistry

View full text Add to dashboard Cite

show abstract

“…These regioselectivities can be explained by the general nucleophilic positions of benzofuran and benzothiophene. Nuclephilic attack of benzofuran proceeds at its C2 position, [16] while nuclephilic attack of benzothiophene proceeds at its C3 position. [17] Dihydronaphthopyran derivatives (5 f-5 h) were obtained from the nonsubstituted o-NQM precursor (4 a) and dimethoxy-o-NQM precursor (4 b) in good yields when allyl silanes were used as olefins.…”

Section: Table 1 Scope Of Substrates [A]mentioning

confidence: 99%

Construction of Functionalized ortho‐Naphthoquinone Methides via Site‐Selective Ring Opening of 1‐Siloxy‐1,4‐epoxy‐1,4‐dihydronaphthalenes

Aijima,

Komagawa,

Akai

et al. 2023

Adv Synth Catal

View full text Add to dashboard Cite

Abstract1‐Siloxy‐4‐(benzyloxy)methyl‐1,4‐epoxy‐1,4‐dihydronaphthalenes, generated from benzynes and furans, underwent automatic site‐selective ring opening because of the synergetic effect of the steric strain of the 1,4‐epoxy moiety and the electron‐donating ability of the siloxy group on the acetal structure to afford the precursors of ortho‐naphthoquinone methides (o‐NQMs). Subsequent Lewis acid‐facilitated o‐NQM formation and annulation with olefins afforded multi‐fused heterocycles. Notably, the consecutive hexacyclic skeleton of rubioncolin B was constructed via solvent‐dependent regioselective annulation of naphthofuran derivatives.

show abstract

“…ortho -Quinomethanes ( o -QMs), featuring highly electrophilic activity and strongly thermodynamic drive to undergo rearomatization, have been recognized as a kind of competent Michael acceptors for synthesizing chiral diarylmethane compounds. − Theoretically, the asymmetric addition of o -QMs with amide nucleophiles would provide direct and atom-efficient approaches to obtain chiral diarylmethylamides. However, despite thorough research and recent breakthroughs in the catalytic conversion of o -QMs, the asymmetric aza-Michael addition of o -QMs has remained to be far from well-developed, which could be demonstrated by the fact that the reaction protocol is limited to using a chiral phosphoric acid catalytic system and strongly nucleophilic nitrogenous synthons such as arenesulfonamides and BocNH 2 .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Chiral Diarylmethylamides via Catalytic Asymmetric Aza-Michael Addition of Amides to ortho-Quinomethanes

Qi,

Sun,

Sun

et al. 2024

J. Org. Chem.

View full text Add to dashboard Cite

Chiral diarylmethylamides are a privileged skeleton in many bioactive molecules. However, the enantioselective synthesis of such molecules remains a long-standing challenge in organic synthesis. Herein, we report a chiral bifunctional squaramide catalyzed asymmetric aza-Michael addition of amides to in situ generated ortho-quinomethanes, affording enantioenriched diarylmethylamides in good yields with excellent enantioselectivities. This work not only provides a new strategy for the construction of the diarylmethylamides but also represents the practicability of amides as nitrogen-nucleophiles in asymmetric organocatalysis.

show abstract

Enantioselective Friedel–Crafts Alkylation of Furans with o-Quinone Methide Using a Chiral Oxazaborolidinium Ion Catalyst

Cited by 14 publications

References 39 publications

Advances in Catalytic Asymmetric Reactions Involving o-Hydroxybenzyl Alcohols

Advances in Catalytic Asymmetric Reactions Involving o-Hydroxybenzyl Alcohols

Construction of Functionalized ortho‐Naphthoquinone Methides via Site‐Selective Ring Opening of 1‐Siloxy‐1,4‐epoxy‐1,4‐dihydronaphthalenes

Synthesis of Chiral Diarylmethylamides via Catalytic Asymmetric Aza-Michael Addition of Amides to ortho-Quinomethanes

Contact Info

Product

Resources

About