Stereoselective Access to Tetra‐ and Tri‐Substituted Fluoro‐ and Chloro‐Borylalkenes via Boron‐Wittig Reaction DOI Open Access

Seungcheol Han,

Yeosan Lee,

Yujin Jung

et al.

Angewandte Chemie, Journal Year: 2022, Volume and Issue: 134(41)

Published: Aug. 23, 2022

Abstract Reported herein is the efficient synthesis of tetra‐ and tri‐substituted ( Z )‐fluoro‐ )‐chloro‐borylalkenes by Boron–Wittig reaction ketones aldehydes with bench‐top stable halo‐diborylmethanes. The substrate scope broad proceeds from a diverse range including biologically relevant molecules fluoro‐ or chloro‐diborylmethanes, providing in good yields high stereoselectivity. utilities obtained are highlighted further modifications to afford fluoroalkene derivatives all‐carbon substituted alkene.

Language: Английский

Sequence‐Dependent Stereodivergent Allylic Alkylation/Fluorination of Acyclic Ketones DOI
Xi‐Jia Liu, Shicheng Jin,

Wen‐Yun Zhang

et al.

Angewandte Chemie, Journal Year: 2019, Volume and Issue: 132(5), P. 2055 - 2059

Published: Nov. 6, 2019

Abstract The stereodivergent iridium‐catalyzed allylic alkylation and fluorination of acyclic ketones is described. α‐Pyridyl‐α‐fluoroketones with vicinal tertiary quaternary stereocenters were obtained in moderate to excellent yields stereoselectivities. Distinct from known synthesis, for which two different chiral catalysts are required general, herein we report a sequence‐dependent synthesis. With only single Ir catalyst, all four possible stereoisomers the products prepared same starting materials by simply adjusting sequence asymmetric varying absolute configuration catalyst.

Language: Английский

Citations

35

Stereoselective Desymmetrization of gem‐Diborylalkanes by “Trifluorination” DOI
N. N. Bhuvan Kumar,

Reddy Rajasekhar Reddy,

Ahmad Masarwa

et al.

Chemistry - A European Journal, Journal Year: 2019, Volume and Issue: 25(34), P. 8008 - 8012

Published: April 9, 2019

An efficient and general method for the chemoselective synthesis of unsymmetrical gem-diborylalkanes is reported. This based on a late-stage desymmetrization through nucleophilic "trifluorination", providing chiral bearing trifluoroborate group. The reaction offers highly modular diastereoselective approach towards gem-diborylcyclopropanes. utility gem-diborylalkane building blocks was demonstrated by selective post-functionalization These functionalizations include inter- intra- Pd-catalyzed Suzuki-Miyaura coupling reactions.

Language: Английский

Citations

30

Generation of α‐Boryl Radicals and Their Conjugate Addition to Enones: Transition‐Metal‐Free Alkylation of gem‐Diborylalkanes DOI

Chaoqiang Wu,

Zhicheng Bao,

Bowen Dou

et al.

Chemistry - A European Journal, Journal Year: 2020, Volume and Issue: 27(7), P. 2294 - 2298

Published: Oct. 16, 2020

Abstract A transition‐metal‐free method for the alkylation of gem ‐diborylalkanes with α ,β‐unsaturated ketones has been developed. It is demonstrated that α‐boryl radicals can be generated efficiently from aid catechol and oxidants. The formed through such process engaged in conjugate addition reaction α,β‐unsaturated ketones. This transformation a straightforward synthesis γ ‐borylketones.

Language: Английский

Citations

18

Iridium‐Catalyzed Asymmetric Allylic Aromatization Reaction DOI
Xi‐Jia Liu, Chao Zheng, Yihan Yang

et al.

Angewandte Chemie, Journal Year: 2019, Volume and Issue: 131(31), P. 10603 - 10609

Published: May 13, 2019

Abstract Described herein is an asymmetric allylic aromatization (AAAr) strategy that employs readily accessible equivalents of benzylic nucleophiles in iridium‐catalyzed substitution reactions with the concomitant formation aromatic rings by aromatization. The optimized reaction conditions involving a catalyst derived from commercially available iridium precursor and Carreira ligand are compatible 4‐ or 5‐methyloxazoles, 5‐methylthiazoles, 5‐methylfurans, 2‐ 3‐methylbenzofurans, 3‐methylbenzothiophene, 3‐methylindole, 1‐methylnaphthalene, methylbenzene. This provides straightforward accesses to valuable heterocyclic compounds, bearing homobenzylic stereogenic center, enantiopure form would be difficult access otherwise. versatility was showcased further elaboration products into useful building blocks drug analogue.

Language: Английский

Citations

15

Electrooxidative Activation of B−B Bond in B2cat2: Access to gem‐Diborylalkanes via Paired Electrolysis DOI Open Access
Bingbing Wang, Xiangyu Zhang,

Yangmin Cao

et al.

Angewandte Chemie, Journal Year: 2023, Volume and Issue: 135(14)

Published: Feb. 1, 2023

Abstract This report describes the unprecedented electrooxidation of a solvent (e.g., DMF)‐ligated B 2 cat complex, whereby solvent‐stabilized boryl radical is formed via quasi‐homolytic cleavage B−B bond in DMF‐ligated cation. Cyclic voltammetry and density functional theory provide evidence to support this novel activation strategy. Furthermore, strategy for electrochemical gem ‐diborylation ‐bromides paired electrolysis developed first time, affording range versatile ‐diborylalkanes, which are widely used synthetic society. Notably, reaction approach scalable, transition‐metal‐free, requires no external activator.

Language: Английский

Citations

4

Zirconium‐Catalyzed Atom‐Economical Synthesis of 1,1‐Diborylalkanes from Terminal and Internal Alkenes DOI Creative Commons
Xianjin Wang, Xin Cui, Sida Li

et al.

Angewandte Chemie, Journal Year: 2020, Volume and Issue: 132(32), P. 13710 - 13714

Published: April 16, 2020

Abstract A general and atom‐economical synthesis of 1,1‐diborylalkanes from alkenes a borane without the need for an additional H 2 acceptor is reported first time. The key to our success use earth‐abundant zirconium‐based catalyst, which allows balance self‐contradictory reactivities (dehydrogenative boration hydroboration) be achieved. Our method avoids using excess amount another alkene as acceptor, was required in other systems. Furthermore, substrates such simple long‐chain aliphatic that did not react before also underwent 1,1‐diboration system. Significantly, unprecedented internal enabled preparation 1,1‐diborylalkanes.

Language: Английский

Citations

9

Diborylmethyl Group as a Transformable Building Block for the Diversification of Nitrogen‐Containing Molecules DOI
Chiwon Hwang,

Yeosan Lee,

Minjae Kim

et al.

Angewandte Chemie, Journal Year: 2022, Volume and Issue: 134(37)

Published: July 18, 2022

Abstract The development of new approaches to installing diverse carbon fragments a nitrogen atom has attracted considerable attention in chemical science. While numerous strategies have been devised forge C(sp 3 )−N bonds, one conceptually powerful and straightforward approach is insert transformable sp ‐carbon unit onto for modular diversification. Here we describe the successful synthesis halo‐diborylmethanes their applications preparation nitrogen‐substituted diborylmethanes through homologative coupling with variety nucleophiles including biologically relevant molecules. This process exhibits remarkably broad substrate scope, usefulness obtained compounds demonstrated by diversification diborylmethyl group access various nitrogen‐containing

Language: Английский

Citations

6

Iridium‐Catalyzed Asymmetric Allylic Substitution of Methyl Azaarenes DOI
Xi‐Jia Liu,

Wen‐Yun Zhang,

Chao Zheng

et al.

Angewandte Chemie, Journal Year: 2022, Volume and Issue: 134(20)

Published: March 3, 2022

Abstract Herein, an Ir‐catalyzed asymmetric allylic substitution reaction of methyl azaarenes is described. Azaarenes such as (benzo)thiazole, oxazole, benzoimidazole, pyridine, and (iso)quinoline are all tolerated. The corresponding chiral azaarene derivatives obtained in good yields with high enantioselectivity (up to 96 % yield 99 ee). utilization the Knochel reagent TMPZnBr⋅LiBr warrants situ formation benzylic nucleophiles without additional activating reagents. 1 H NMR studies suggested a two‐fold function this reaction. synthetic utility method has been showcased by concise enantioselective synthesis allosteric protein kinase modulator.

Language: Английский

Citations

4

Cobalt‐Catalyzed Asymmetric Sequential Hydroboration/Isomerization/Hydroboration of 2‐Aryl Vinylcyclopropanes DOI
Chen‐Hui Chen, Hongliang Wang, Tongtong Li

et al.

Angewandte Chemie, Journal Year: 2022, Volume and Issue: 134(30)

Published: May 24, 2022

Abstract A cobalt‐catalyzed asymmetric sequential hydroboration/isomerization/hydroboration of 2‐aryl vinylcyclopropanes was for the first time reported preparation valuable chiral 1,5‐bis(boronates) in good yields with excellent enantioselectivity via isomerization/hydroboration a trisubstituted alkene intermediate. The reaction carried out smoothly and this protocol used syntheses (−)‐preclamol gram‐scale. two primary C ( sp 3) −B bonds could be distinguished iterative Suzuki–Miyaura cross‐coupling reaction, delivering 1,2,5‐triaryl alkanes enantioselectivity. Based on experimental computational studies, cobalt‐hydride species proposed as active intermediate hydroboration, isomerization, second hydroboration reactions.

Language: Английский

Citations

3

Stereoselective Access to Tetra‐ and Tri‐Substituted Fluoro‐ and Chloro‐Borylalkenes via Boron‐Wittig Reaction DOI Open Access

Seungcheol Han,

Yeosan Lee,

Yujin Jung

et al.

Angewandte Chemie, Journal Year: 2022, Volume and Issue: 134(41)

Published: Aug. 23, 2022

Abstract Reported herein is the efficient synthesis of tetra‐ and tri‐substituted ( Z )‐fluoro‐ )‐chloro‐borylalkenes by Boron–Wittig reaction ketones aldehydes with bench‐top stable halo‐diborylmethanes. The substrate scope broad proceeds from a diverse range including biologically relevant molecules fluoro‐ or chloro‐diborylmethanes, providing in good yields high stereoselectivity. utilities obtained are highlighted further modifications to afford fluoroalkene derivatives all‐carbon substituted alkene.

Language: Английский

Citations

2