Reaction rate differences between organotrifluoroborates and boronic acids in BINOL-catalyzed conjugate addition to enones

被引：6

作者：

Brooks, Bailey ^{[1
]}

Hiller, Noemi ^{[1
]}

May, Jeremy A. ^{[1
]}

机构：

[1] Univ Houston, Dept Chem, 3585 Cullen Blvd,Fleming Bldg Rm 112, Houston, TX 77204 USA

来源：

TETRAHEDRON LETTERS | 2021年 / 83卷

关键词：

Conjugate Addition; Organocatalysis; Trifluoroborate; Organoboronate; Hammett plot; ASYMMETRIC MICHAEL ADDITION; ALKENYLBORONIC ACIDS; ALPHA; BETA-UNSATURATED KETONES; 1,4-ADDITION REACTION; ALLYLIC SUBSTITUTION; ARYLBORONIC ACIDS; PROTODEBORONATION; ALKENYLATION; REAGENTS; ALKENES;

D O I：

10.1016/j.tetlet.2021.153412

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Enantioselective organocatalysis has been successfully employed in combination with trifluoroborate reagents for novel organic transformations over the last decade. However, no experimental rate studies of these reactions have been reported. Herein we report Hammett plot analysis of the organocatalyzed enantioselective conjugate addition of alkenyl, aryl, and heteroaryl trifluoroborate salts to chalcone derivatives with substitution at both the beta-aryl and keto-aryl positions. The rate trend for keto-aryl substitution diverges from that of boronic acid nucleophiles in that the keto-aryl substituent for trifluoroborate salts does not measurably impact reaction rate in a manner consistent with charge stabilization. In addition, variable temperature NMR in combination with quantitative thin-layer chromatography (TLC) analysis suggests that the reaction is impacted by the low solubility of the trifluoroborate salts, so particle size and stirring speed affect reaction rates. (C) 2021 Elsevier Ltd. All rights reserved.

引用

页数：6

共 52 条

[11] Air- and Moisture-Stable Amphoteric Molecules: Enabling Reagents in Synthesis[J]. He, Zhi;Zajdlik, Adam;Yudin, Andrei K. ACCOUNTS OF CHEMICAL RESEARCH, 2014(04)
[12] Pt-Ru model catalysts for anodic methanol oxidation:: Influence of structure and composition on the reactivity[J]. Hoster, H;Iwasita, T;Baumgärtner, H;Vielstich, W. PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2001(03)
[13] Hydroxyl Group-Directed Organocatalytic Asymmetric Michael Addition of α,β-Unsaturated Ketones with Alkenylboronic Acids[J]. Inokuma, Tsubasa;Takasu, Kiyosei;Sakaeda, Toshiyuki;Takemoto, Yoshiji. ORGANIC LETTERS, 2009(11)
[14] Recent advances in enantioselective copper-catalyzed 1,4-addition[J]. Jerphagnon, Thomas;Pizzuti, M. Gabriella;Minnaard, Adriaan J.;Feringa, Ben L. CHEMICAL SOCIETY REVIEWS, 2009(04)
[15] Komnenos T., 1883, LIEBIGS ANN CHEM, V218, P145
[16] Scope and Mechanistic Study of the Coupling Reaction of α,β-Unsaturated Carbonyl Compounds with Alkenes: Uncovering Electronic Effects on Alkene Insertion vs Oxidative Coupling Pathways[J]. Kwon, Ki-Hyeok;Lee, Do W.;Yi, Chae S. ORGANOMETALLICS, 2012(01)
[17] Organocatalytic vinyl and Friedel-Crafts alkylations with trifluoroborate salts[J]. Lee, Sandra;MacMillan, David W. C. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2007(50)
[18] Selection of boron reagents for Suzuki-Miyaura coupling[J]. Lennox, Alastair J. J.;Lloyd-Jones, Guy C. CHEMICAL SOCIETY REVIEWS, 2014(01)
[19] Catalytic enantioselective conjugate addition with Grignard reagents[J]. Lopez, Fernando;Minnaard, Adriaan J.;Feringa, Ben L. ACCOUNTS OF CHEMICAL RESEARCH, 2007(03)
[20] Base-Promoted Protodeboronation of 2,6-Disubstituted Arylboronic Acids[J]. Lozada, Jerome;Liu, Zhibo;Perrin, David M. JOURNAL OF ORGANIC CHEMISTRY, 2014(11)

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