Wing-Yiu Yu

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Organization: The Hong Kong Polytechnic University , HongKong

Department: State Key Laboratory for Chirosciences and Department of Applied Biology and Chemical Technology

Title: Associate Professor(PhD)

TOPICS

Organic Chemistry

Amination

Chemicals
References

Cp*Rh(III)-Catalyzed Cross-Coupling of Alkyltrifluoroborate with α-Diazomalonates for C(sp3)–C(sp3) Bond Formation

Co-reporter:Yin-Suo Lu and Wing-Yiu Yu

Organic Letters 2016 Volume 18(Issue 6) pp:1350-1353

Publication Date(Web):February 29, 2016

DOI:10.1021/acs.orglett.6b00283

A Cp*Rh(III)-catalyzed cross-coupling of alkyltrifluoroborate with α-diazomalonates was developed; the C(sp3)–C(sp3) bond coupled products were formed in up to 97% yields. The reaction tolerates some useful functional groups, including ketone, ester, amide, ether, sulfonyl, and thiophene. Electrospray ionization mass spectrometry (ESI-MS) analysis revealed the formation of a distinct molecular species corresponding to σ-alkylrhodium(III) complexes. The successful diazo coupling reaction may be attributed to coordination of the amide group that promotes stability of the alkylrhodium(III) complex through the formation of a five-membered metallacycle.

Cp*Rh(III)-catalyzed electrophilic amination of arylboronic acids with azo compounds for synthesis of arylhydrazides

Co-reporter:Yan-Fung Lau, Chun-Ming Chan, Zhongyuan Zhou and Wing-Yiu Yu

Organic & Biomolecular Chemistry 2016 vol. 14(Issue 28) pp:6821-6825

Publication Date(Web):16 Jun 2016

DOI:10.1039/C6OB00719H

A [Cp*Rh(III)]-catalyzed electrophilic amination of arylboronic acids with diethyl azodicarboxylate (DEAD) was developed, and arylhydrazides were produced in excellent yields and selectivity. The analogous amination with the arylazocarboxylates afforded the corresponding N,N-diarylhydrazides. The electrophilic amination of arylboronic acids with azocarboxylates proceeds readily under mild conditions with excellent functional group tolerance. Up to 99% yields were obtained. Preliminary mechanistic studies revealed that prior formation of an arylrhodium(III) intermediate for the azo coupling reaction can be ruled out.

[RhIII(Cp*)]-Catalyzed Cascade Arylation and Chlorination of α-Diazocarbonyl Compounds with Arylboronic Acids and N-Chlorosuccinimide for Facile Synthesis of α-Aryl-α-chloro Carbonyl Compounds

Co-reporter:Fo-Ning Ng, Yan-Fung Lau, Zhongyuan Zhou, and Wing-Yiu Yu

Organic Letters 2015 Volume 17(Issue 7) pp:1676-1679

Publication Date(Web):March 16, 2015

DOI:10.1021/acs.orglett.5b00440

A Rh(III)-catalyzed cascade arylation and chlorination of α-diazocarbonyl compounds with arylboronic acids and N-chlorosuccinimide was achieved. The reaction exhibits excellent functional group tolerance on the organoboron and the diazo reagents; the functionalized α-aryl-α-chlorocarbonyl compounds were obtained in up to 86% yields. The cascade reaction should involve migratory carbene insertion of arylrhodium(III) to form some reactive rhodium(III)–diketonate complexes. Its subsequent reaction with N-chlorosuccinmide afforded the α-chlorocarbonyl products.

Copper-catalyzed cross-dehydrogenative coupling of N-arylacrylamides with chloroform using tert-butyl peroxybenzoate as oxidant for the synthesis of trichloromethylated 2-oxindoles

Co-reporter:Chun-Wo Chan, Pui-Yiu Lee, Wing-Yiu Yu

Tetrahedron Letters 2015 Volume 56(Issue 20) pp:2559-2563

Publication Date(Web):13 May 2015

DOI:10.1016/j.tetlet.2015.03.109

A Cu-catalyzed cross-dehydrogenative coupling of N-arylacrylamides with chloroform is achieved using tert-butyl peroxybenzoate as oxidant, and trichloromethylated oxindoles were obtained in excellent yield and regioselectivity. This reaction should proceed by cascade CCl3 radical CC addition and aryl cyclization.

Rhodium(III)-catalyzed formal oxidative [4 + 1] cycloaddition of benzohydroxamic acids and α-diazoesters. A facile synthesis of functionalized benzolactams

Co-reporter:Hon-Wah Lam, Ka-Yi Man, Wai-Wing Chan, Zhongyuan Zhou and Wing-Yiu Yu

Organic & Biomolecular Chemistry 2014 vol. 12(Issue 24) pp:4112-4116

Publication Date(Web):01 Apr 2014

DOI:10.1039/C4OB00512K

A Rh(III)-catalyzed oxidative [4 + 1] cycloaddition of benzohydroxamic acids and α-diazoesters is achieved to afford benzolactams in up to 93% yields. With the N-OAc amido moiety as a directing group, the ortho-C–H is selectively functionalized and the catalytic reaction exhibits excellent tolerance to different functional substituents. A notable rhodacyclic complex is isolated and structurally characterized, suggesting that C–H/N–H cyclometallation is a key step in the catalytic cycle.

[RhIII(Cp*)]-Catalyzed ortho-Selective Direct C(sp2)H Bond Amidation/Amination of Benzoic Acids by N-Chlorocarbamates and N-Chloromorpholines. A Versatile Synthesis of Functionalized Anthranilic Acids

Co-reporter:Fo-Ning Ng;Dr. Zhongyuan Zhou ;Dr. Wing-Yiu Yu

Chemistry - A European Journal 2014 Volume 20( Issue 15) pp:4474-4480

Publication Date(Web):

DOI:10.1002/chem.201304855

Abstract

A Rh^III-catalyzed direct ortho-CH amidation/amination of benzoic acids with N-chlorocarbamates/N-chloromorpholines was achieved, giving anthranilic acids in up to 85 % yields with excellent ortho-selectivity and functional-group tolerance. Successful benzoic acid aminations were achieved with carbamates bearing various amide groups including NHCO₂Me, NHCbz, and NHTroc (Cbz=carbobenzyloxy; Troc=trichloroethylchloroformate), as well as secondary amines, such as morpholines, piperizines, and piperidines, furnishing highly functionalized anthranilic acids. A stoichiometric reaction of a cyclometallated rhodium(III) complex of benzo[h]quinoline with a silver salt of N-chlorocarbamate afforded an amido–rhodium(III) complex, which was isolated and structurally characterized by X-ray crystallography. This finding confirmed that the CN bond formation results from the cross-coupling of N-chlorocarbamate with the aryl–rhodium(III) complex. Yet, the mechanistic details regarding the CN bond formation remain unclear; pathways involving 1,2-aryl migration and rhodium(V)– nitrene are plausible.

[Cp*RhCl2]2-catalyzed ortho-C–H bond amination of acetophenone o-methyloximes with primary N-chloroalkylamines: convenient synthesis of N-alkyl-2-acylanilines

Co-reporter:Ka-Ho Ng, Zhongyuan Zhou and Wing-Yiu Yu

Chemical Communications 2013 vol. 49(Issue 63) pp:7031-7033

Publication Date(Web):29 May 2013

DOI:10.1039/C3CC42937G

Rh(III)-catalyzed aromatic C–H amination of acetophenone o-methyloximes with primary N-chloroalkylamines was developed, and the arylamine products were obtained in up to 92% yield. The reaction probably involves rate-limiting electrophilic C–H bond cleavage (kH/kD = 2).

Palladium-catalyzed oxidative direct C–H/C–H cross coupling of anilides with β-keto esters

Co-reporter:Wai-Wing Chan, Zhongyuan Zhou and Wing-Yiu Yu

Chemical Communications 2013 vol. 49(Issue 74) pp:8214-8216

Publication Date(Web):16 Jul 2013

DOI:10.1039/C3CC44769C

A Pd(II)-catalyzed oxidative direct C(sp2)–H/C(sp3)–H cross coupling of anilides with α-dicarbonyl compounds with Mn(OAc)3·2H2O as the oxidant is reported and this protocol provides facile access to α-aryl malonates and β-keto esters in good yields and regioselectivity.

Rh-Catalyzed Intermolecular Carbenoid Functionalization of Aromatic C–H Bonds by α-Diazomalonates

Co-reporter:Wai-Wing Chan ; Siu-Fung Lo ; Zhongyuan Zhou

Journal of the American Chemical Society 2012 Volume 134(Issue 33) pp:13565-13568

Publication Date(Web):August 3, 2012

DOI:10.1021/ja305771y

A Rh-catalyzed intermolecular coupling of diazomalonates with arene C–H bonds is reported. The reaction is initiated by electrophilic C–H activation, which is followed by coupling of the arylrhodium(III) complex with the diazomalonate. In most cases, arenes with oximes, carboxylic acids, and amines as directing groups cross-couple with diazomalonates with excellent regioselectivities and functional group tolerance, and thus, this reaction offers a new route to α-aryl carbonyl compounds for specific applications.

A convenient synthesis of anthranilic acids by Pd-catalyzed direct intermolecular ortho-C–H amidation of benzoic acids

Co-reporter:Ka-Ho Ng, Fo-Ning Ng and Wing-Yiu Yu

Chemical Communications 2012 vol. 48(Issue 95) pp:11680-11682

Publication Date(Web):16 Oct 2012

DOI:10.1039/C2CC36502B

An efficient method for synthesis of anthranilic acids by Pd-catalyzed ortho-C–H amidation of benzoic acids is disclosed. The amidation is proposed to proceed by carboxylate-assisted ortho-C–H palladation to form an arylpalladium(II) complex, followed by nitrene insertion to the Pd–C bond.

Palladium-catalyzed oxidative direct C–H/C–H cross coupling of anilides with β-keto esters

Co-reporter:Wai-Wing Chan, Zhongyuan Zhou and Wing-Yiu Yu

Chemical Communications 2013 - vol. 49(Issue 74) pp:NaN8216-8216

Publication Date(Web):2013/07/16