Tamio Hayashi

The reaction of 3-sulfolene with arylboronic acids in the presence of a chiral diene-rhodium catalyst under highly basic conditions (10 equiv of KOH) gave high yields of 3-arylsulfolanes with high enantioselectivity, where 3-sulfolene is in equilibration with 2-sulfolene by base-catalyzed isomerization and the more reactive 2-sulfolene undergoes the rhodium-catalyzed asymmetric arylation.

Asymmetric Synthesis of Triarylmethanes by Rhodium-Catalyzed Enantioselective Arylation of Diarylmethylamines with Arylboroxines

Co-reporter:Yinhua Huang

Journal of the American Chemical Society 2015 Volume 137(Issue 24) pp:7556-7559

Publication Date(Web):June 2, 2015

DOI:10.1021/jacs.5b03277

The reaction of racemic diarylmethylamines, (Ar1Ar2CHNR2), where Ar1 is substituted with a 2-hydroxy group, with arylboroxines (Ar3BO)3 in the presence of a chiral diene-rhodium catalyst gave high yields of chiral triarylmethanes (Ar1Ar2CH*Ar3) with high enantioselectivity (up to 97% ee). The reaction is assumed to proceed through o-quinone methide intermediates which undergo Rh-catalyzed asymmetric 1,4-addition of the arylboron reagents.

A chiral phosphine–olefin ligand derived from l-hydroxyproline and its use in the rhodium-catalyzed asymmetric 1,4-addition

Co-reporter:Vasudeva Rao Gandi, Yixin Lu, Tamio Hayashi

Tetrahedron: Asymmetry 2015 Volume 26(12–13) pp:679-682

Publication Date(Web):15 July 2015

DOI:10.1016/j.tetasy.2015.05.004

A new chiral phosphine–olefin ligand (S)-1 has been designed and synthesized from l-hydroxyproline via a short reaction sequence. It was examined for its efficiency in the rhodium-catalyzed asymmetric addition of arylboronic acids and a phenylzinc reagent to cyclic α,β-unsaturated ketones, giving 1,4-addition products with high enantioselectivities.(S)-tert-Butyl 2-((diphenylphosphino)methyl)-2,5-dihydro-1H-pyrrole-1-carboxylateC12H26NO2P[α]D25 = −54 (c 1.0, CHCl3)Source of chirality: l-HydroxyprolineAbsolute configuration: (S)(S)-tert-Butyl 2-((tosyloxy)methyl)-2,5-dihydro-1H-pyrrole-1-carboxylateC17H23NO5S[α]D25 = −117 (c 1.10, CHCl3)Source of chirality: l-HydroxyprolineAbsolute configuration: (S)

Asymmetric Synthesis of P-Stereogenic Diarylphosphinites by Palladium-Catalyzed Enantioselective Addition of Diarylphosphines to Benzoquinones

Co-reporter:Yinhua Huang ; Yongxin Li ; Pak-Hing Leung

Journal of the American Chemical Society 2014 Volume 136(Issue 13) pp:4865-4868

Publication Date(Web):March 17, 2014

DOI:10.1021/ja501007t

The reaction of phenyl(2,4,6-trimethylphenyl)phosphine with a substituted benzoquinone in the presence of a chiral phosphapalladacycle complex as a catalyst and triethylamine in chloroform at −45 °C proceeded in a new type of addition manner to give a high yield of a 4-hydroxyphenyl phenyl(2,4,6-trimethylphenyl)phosphinite with 98% enantioselectivity, which is a versatile intermediate readily convertible into various phosphines and their derivatives with high enantiomeric purity.

Synthesis of Quaternary Carbon Stereocenters by Copper-Catalyzed Asymmetric Allylic Substitution of Allyl Phosphates with Arylboronates

Co-reporter:Momotaro Takeda, Keishi Takatsu, Ryo Shintani, and Tamio Hayashi

The Journal of Organic Chemistry 2014 Volume 79(Issue 6) pp:2354-2367

Publication Date(Web):March 6, 2014

DOI:10.1021/jo500068p

A copper-catalyzed asymmetric allylic substitution of γ,γ-disubstituted allyl phosphates with arylboronates has been developed for the construction of quaternary stereocenters. High regio- and enantioselectivities have been achieved by employing a hydroxy-bearing chiral N-heterocyclic carbene ligand, and both E and Z substrates provide the same enantiomer as the major product. The mechanistic aspect of this catalysis has also been investigated to find that a 1:1 copper/ligand complex is most likely responsible for the present asymmetric catalysis, and the reaction proceeds with almost perfect 1,3-anti stereochemistry with respect to the allylic electrophile.

High Performance of a Palladium Phosphinooxazoline Catalyst in the Asymmetric Arylation of Cyclic N-Sulfonyl Ketimines

Co-reporter:Chunhui Jiang;Dr. Yixin Lu;Dr. Tamio Hayashi

Angewandte Chemie International Edition 2014 Volume 53( Issue 37) pp:9936-9939

Publication Date(Web):

DOI:10.1002/anie.201406147

Abstract

A cationic palladium complex with a chiral phosphine-oxazoline ligand (iPr-phox) showed high catalytic activity and enantioselectivity in the asymmetric addition of arylboronic acids to six-membered cyclic N-sulfonyl ketimines to give high yields of the corresponding chiral cyclic sulfamidates with 96–99.9 % ee. The products have tetrasubstituted stereogenic centers with an amino group and a triaryl or alkyldiaryl group as substituents.

Rhodium-Catalyzed Asymmetric Hydroarylation of 3-Pyrrolines Giving 3-Arylpyrrolidines: Protonation as a Key Step

Co-reporter:Chau Ming So ; Satoshi Kume

Journal of the American Chemical Society 2013 Volume 135(Issue 30) pp:10990-10993

Publication Date(Web):July 18, 2013

DOI:10.1021/ja406169s

A hydroxorhodium complex coordinated with (R)-segphos was found to catalyze the hydroarylation of 3-pyrrolines with arylboroxines under neutral conditions to give 3-arylpyrrolidines with high enantioselectivity in high yields.

Single electron transfer-induced Grignard cross-coupling involving ion radicals as exclusive intermediates

Co-reporter:Nanase Uchiyama, Eiji Shirakawa and Tamio Hayashi

Chemical Communications 2013 vol. 49(Issue 4) pp:364-366

Publication Date(Web):15 Nov 2012

DOI:10.1039/C2CC37643A

The mechanism of the previously developed cross-coupling reaction of aryl Grignard reagents with aryl halides was explored in more detail. Single electron transfer from an aryl Grignard reagent to an aryl halide initiates a radical chain by giving an anion radical of the aryl halide. The following propagation cycle consists entirely of anion radical intermediates.

Rhodium-Catalyzed Asymmetric Cycloisomerization of 1,6-Ene-ynamides

Co-reporter:Takahiro Nishimura;Yuka Takiguchi;Yuko Maeda

Advanced Synthesis & Catalysis 2013 Volume 355( Issue 7) pp:1374-1382

Publication Date(Web):

DOI:10.1002/adsc.201300148

Abstract

The rhodium-catalyzed asymmetric cycloisomerization of heteroatom-bridged 1,6-ene-ynamides proceeded to give high yields of functionalized 3-aza- and oxabicyclo[4.1.0]heptene derivatives with high enantioselectivity, which was achieved by use of a rhodium/chiral diene catalyst. The 1,6-ene-ynamides substituted with 2-oxazolidinone and 2-azetidinone moieties at the alkyne terminus were found to display high reactivity towards the rhodium/chiral diene catalyst, where the chelate coordination of the alkyne moiety and the carbonyl oxygen of the ene-ynamides might be responsible for the high catalytic activity.

Hydroxorhodium/Chiral Diene Complexes as Effective Catalysts for the Asymmetric Arylation of 3-Aryl-3-hydroxyisoindolin-1-ones

Co-reporter:Dr. Takahiro Nishimura;Akira Noishiki;Yusuke Ebe;Dr. Tamio Hayashi

Angewandte Chemie International Edition 2013 Volume 52( Issue 6) pp:1777-1780

Publication Date(Web):

DOI:10.1002/anie.201208593

Enantioselective Synthesis of α-Tri- and α-Tetrasubstituted Allylsilanes by Copper-Catalyzed Asymmetric Allylic Substitution of Allyl Phosphates with Silylboronates

Co-reporter:Momotaro Takeda, Ryo Shintani, and Tamio Hayashi

The Journal of Organic Chemistry 2013 Volume 78(Issue 10) pp:5007-5017

Publication Date(Web):April 28, 2013

DOI:10.1021/jo400888b

A copper/N-heterocyclic carbene-catalyzed asymmetric allylic substitution of allyl phosphates with a silylboronate has been developed to give highly enantioenriched allylsilanes. High regioselectivity has been achieved by employing NaOH as the base, and this catalyst system is effective for both γ-mono- and disubstituted allyl phosphates.

Rhodium-Catalyzed Asymmetric Synthesis of Silicon-Stereogenic Dibenzooxasilines via Enantioselective Transmetalation

Co-reporter:Ryo Shintani ; Eleanor E. Maciver ; Fumiko Tamakuni

Journal of the American Chemical Society 2012 Volume 134(Issue 41) pp:16955-16958

Publication Date(Web):September 22, 2012

DOI:10.1021/ja3076555

A rhodium-catalyzed asymmetric synthesis of silicon-stereogenic dibenzooxasilines has been developed. High enantioselectivities have been achieved by employing (S,S)-Me-Duphos as the ligand through “enantioselective transmetalation”.

Cobalt-Catalyzed Asymmetric 1,6-Addition of (Triisopropylsilyl)-acetylene to α,β,γ,δ-Unsaturated Carbonyl Compounds

Co-reporter:Takahiro Sawano ; Akram Ashouri ; Takahiro Nishimura

Journal of the American Chemical Society 2012 Volume 134(Issue 46) pp:18936-18939

Publication Date(Web):November 6, 2012

DOI:10.1021/ja309756k

Asymmetric addition of (triisopropylsilyl)acetylene to α,β,γ,δ-unsaturated carbonyl compounds took place in the presence of a cobalt/Duphos catalyst to give the 1,6-addition products in high yields with high regio- and enantioselectivity.

Palladium-Catalyzed Synthesis of 4-Oxaspiro[2.4]heptanes via Central Attack of Oxygen Nucleophiles to π-Allylpalladium Intermediates

Co-reporter:Ryo Shintani, Tomoaki Ito, and Tamio Hayashi

Organic Letters 2012 Volume 14(Issue 9) pp:2410-2413

Publication Date(Web):April 24, 2012

DOI:10.1021/ol300852v

A palladium-catalyzed decarboxylative cyclopropanation of γ-methylidene-δ-valerolactones with aromatic aldehydes has been developed to give 4-oxaspiro[2.4]heptanes with high selectivity. The site of nucleophilic attack to a π-allylpalladium intermediate has been controlled with a sterically demanding phosphine ligand. The course of the reaction is highly dependent on ligands and solvents, and selective formation of methylenetetrahydropyrans has also been realized.

Palladium-Catalyzed Desymmetrization of Silacyclobutanes with Alkynes: Enantioselective Synthesis of Silicon-Stereogenic 1-Sila-2-cyclohexenes and Mechanistic Considerations

Co-reporter:Ryo Shintani, Kohei Moriya, and Tamio Hayashi

Organic Letters 2012 Volume 14(Issue 11) pp:2902-2905

Publication Date(Web):May 21, 2012

DOI:10.1021/ol301191u

A palladium-catalyzed enantioselective desymmetrization of silacyclobutanes with alkynes has been developed to give silicon-stereogenic 1-sila-2-cyclohexenes with high enantioselectivity. The products thus obtained undergo further derivatizations with complete stereoselectivity, and a new catalytic cycle involving alkyne coordination (oxidative cyclization)–transmetalation (σ-bond metathesis)–reductive elimination has also been proposed.

Palladium-catalyzed asymmetric synthesis of 2-pyrrolidinones with a quaternary carbon stereocenter

Co-reporter:Ryo Shintani, Tomoaki Ito, Midori Nagamoto, Haruka Otomo and Tamio Hayashi

Chemical Communications 2012 vol. 48(Issue 79) pp:9936-9938

Publication Date(Web):30 Aug 2012

DOI:10.1039/C2CC35259A

A palladium-catalyzed asymmetric synthesis of 2-pyrrolidinones with a quaternary stereocenter at the 3-position has been achieved by the reaction of γ-methylidene-δ-valerolactones with alkyl isocyanates. High enantioselectivity has been realized by employing a newly synthesized chiral phosphoramidite ligand.

Single electron transfer-induced Grignard cross-coupling involving ion radicals as exclusive intermediates

Co-reporter:Nanase Uchiyama, Eiji Shirakawa and Tamio Hayashi

Chemical Communications 2013 - vol. 49(Issue 4) pp:NaN366-366

Publication Date(Web):2012/11/15

DOI:10.1039/C2CC37643A

Palladium-catalyzed asymmetric synthesis of 2-pyrrolidinones with a quaternary carbon stereocenter

Co-reporter:Ryo Shintani, Tomoaki Ito, Midori Nagamoto, Haruka Otomo and Tamio Hayashi

Chemical Communications 2012 - vol. 48(Issue 79) pp:NaN9938-9938

Publication Date(Web):2012/08/30

DOI:10.1039/C2CC35259A