2016年6月22日水曜日

A Career in Catalysis: Masakatsu Shibasaki - ACS Catalysis (ACS Publications)

A Career in Catalysis: Masakatsu Shibasaki

Naoya Kumagai^*^†, Motomu Kanai^*^‡, and Hiroaki Sasai^*^§

^† Institute
of Microbial Chemistry (BIKAKEN), Tokyo, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan

^‡ Graduate
School of Pharmaceutical Sciences, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

^§ The
Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki-shi, Osaka 567-0047, Japan

ACS Catal., 2016, 6, pp 4699–4709

DOI: 10.1021/acscatal.6b01227

Publication Date (Web): June 20, 2016

*E-mail: nkumagai@bikaken.or.jp., *E-mail: kanai@mol.f.u-tokyo.ac.jp., *E-mail: sasai@sanken.osaka-u.ac.jp.

Abstract

Professor
Masakatsu Shibasaki’s distinguished scientific accomplishments in the
field of asymmetric catalysis are compiled here with particular emphasis
on multimetallic cooperative catalysis. In 1992, he discovered
revolutionary multimetallic chiral complexes composed of a rare earth
metal, alkaline metals, and 1,1′-binaphthyl-2-binaphthols (BINOLs) that
promoted a number of enantioselective reactions in a highly efficient
and stereoselective manner. This finding resulted in chiral
multimetallic catalysts that have significantly advanced the field of
enantioselective catalysis.

Ligand-Enabled, Copper-Catalyzed Regio- and Stereoselective Synthesis of Trialkylsubstituted Alkenylboronates from Unactivated Internal Alkynes - Journal of the American Chemical Society (ACS Publications)

Ligand-Enabled, Copper-Catalyzed Regio- and Stereoselective Synthesis of Trialkylsubstituted Alkenylboronates from Unactivated Internal Alkynes - Journal of the American Chemical Society (ACS Publications)

Taisuke Itoh^†, Yohei Shimizu^†, and Motomu Kanai^*^†^‡

^† Graduate
School of Pharmaceutical Sciences, The University
of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

^‡ Kanai
Life Science Catalysis Project, ERATO, Japan
Science Technology Agency, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

J. Am. Chem. Soc., 2016, 138 (24), pp 7528–7531

DOI: 10.1021/jacs.6b04646

Publication Date (Web): June 07, 2016

*kanai@mol.f.u-tokyo.ac.jp

Abstract

We
report the first copper-catalyzed regio- and stereoselective
borylalkylation of dialkylsubstituted internal alkynes with
bis(pinacolato)diboron and alkyl halides. A catalytically generated
borylcopper species containing a novel π-accepting N-heterocyclic
carbene ligand chemoselectively reacted with unactivated internal
alkynes over alkyl halides. The intermediate alkenylcopper species
subsequently reacted with alkyl halides, affording the desired products.
The copper catalyst differentiated steric demands between the two
aliphatic substituents on the C≡C triple bond of the alkyne substrates
to exhibit high regioselectivity from a wide range of alkyne/alkyl
halide combinations. This method is useful for the straightforward
synthesis of trialkylsubstituted alkenylboronates, i.e., versatile
precursors for tetrasubstituted alkenes containing three or four
different alkylsubstituents, which are difficult to synthesize by other
methods.

Nickel-Catalyzed Asymmetric Kumada Cross-Coupling of Symmetric Cyclic Sulfates - Journal of the American Chemical Society (ACS Publications)

Meredith S. Eno, Alexander Lu, and James P. Morken^*

Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States

J. Am. Chem. Soc., Article ASAP

DOI: 10.1021/jacs.6b03384

Publication Date (Web): June 08, 2016

*morken@bc.edu

Abstract

Nickel-catalyzed
enantioselective cross-couplings between symmetric cyclic sulfates and
aromatic Grignard reagents are described. These reactions are effective
with a broad range of substituted cyclic sulfates and deliver products
with asymmetric tertiary carbon centers. Mechanistic experiments point
to a stereoinvertive S_N2-like oxidative addition of a nickel complex to the electrophilic substrate.

Selective Catalytic Oxidation of Unprotected Carbohydrates - ACS Catalysis (ACS Publications)

Kevin Chung and Robert M. Waymouth^*

Department of Chemistry, Stanford University, Stanford, 94305 California, United States

ACS Catal., 2016, 6, pp 4653–4659

DOI: 10.1021/acscatal.6b01501

Publication Date (Web): June 06, 2016

*E-mail: waymouth@stanford.edu.

Abstract

The
development of new strategies for the direct catalytic
functionalization of unprotected carbohydrates would be an enabling
advance for glycoscience. Herein we report that the catalytic oxidation
of unprotected carbohydrates can be carried out selectively with
[(neocuproine)Pd(OAc)]₂(OTf)₂ (1) to
generate the 3-ketoses. Catalytic aerobic oxidation can be carried out
with Pd loadings as low as 1% in the presence of phenolic additives.
Catalytic oxidation of a variety of unprotected pyranosides in
acetonitrile or acetonitrile/water with Pd catalyst 1 with either
oxygen or benzoquinone selectively generates the 3-ketoses. Minor
amounts of the 4-ketoses are formed competitively, particularly in the
case of pyranosides bearing axial substituents at C4 of the pyranoside.
Catalytic oxidations can also be carried out in trifluorethanol, but for
pyranosides bearing axial substituents at C2 or C4, selective oxidation
to the 3-ketose is accompanied by epimerization to afford the
equatorial 3-ketoses. Catalytic oxidation of unprotected hexafuranosides
or sialic acid derivatives occurs selectively at the exocyclic diol or
triol in trifluoroethanol to generate exocyclic hydroxyketones.

Palladium-Catalyzed Regioselective C–H Bond Arylations of Benzoxazoles and Benzothiazoles at the C7 Position - ACS Catalysis (ACS Publications)

Fatma Abdellaoui^†^‡, Chiraz Youssef^‡, Hamed Ben Ammar^‡, Thierry Roisnel^†, Jean-François Soulé^*^†, and Henri Doucet^*^†

^† Institut des Sciences
Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes “Organométalliques:
Matériaux et Catalyse”, Campus de Beaulieu, 35042 Rennes, France

^‡ Laboratoire de
Synthèse Organique Asymétrique et Catalyse Homogène,
(UR 11ES56) Université de Monastir, Faculté des Sciences
de Monastir, Avenue de l’environnement, Monastir 5000, Tunisia

ACS Catal., 2016, 6, pp 4248–4252

DOI: 10.1021/acscatal.6b00678

Publication Date (Web): May 31, 2016

*E-mail: jean-francois.soule@univ-rennes1.fr., *E-mail: henri.doucet@univ-rennes1.fr.

Abstract

We
report herein, a very simple catalytic system for the direct arylation
of benzoxazole and benzothiazole derivatives at C7 position, namely,
phosphine-free PdCl₂ associated with PivOK in NMP at 150 °C.
(Thio)phenoxy chelation-assisted Pd-catalyzed C–H bond cleavage, from an
opened intermediate, was proposed to explain this unique
regioselectivity. This reaction allows the synthesis of
2-amino-6-arylphenols through the ring opening of the benzoxazole.

2,5-Oxyarylation of Furans: Synthesis of Spiroacetals via Palladium-Catalyzed Aerobic Oxidative Coupling of Boronic Acids with α-Hydroxyalkylfurans - Organic Letters (ACS Publications)

Jiuyi Li, Hui Peng, Furong Wang, Xiujun Wang, Huanfeng Jiang, and Biaolin Yin^*

School of Chemistry and Chemical
Engineering, South China University of Technology, Guangzhou 510641, China

Org. Lett., Article ASAP

DOI: 10.1021/acs.orglett.6b01472

Publication Date (Web): June 16, 2016

*E-mail: blyin@scut.edu.cn.

Abstract

A
protocol for the 2,5-oxyarylation of furan rings via Pd-catalyzed
aerobic oxidative coupling of boronic acids with α-hydroxyalkylfurans is
reported. This protocol provides rapid, green access to diverse
biologically interesting and synthetically useful unsaturated
spiroacetals from sustainable furan derivatives.

Ruthenium-Catalyzed Dehydrogenative β-Benzylation of 1,2,3,4-Tetrahydroquinolines with Aryl Aldehydes: Access to Functionalized Quinolines - Organic Letters (ACS Publications)

Zhenda Tan, Huanfeng Jiang, and Min Zhang^*

School of Chemistry &
Chemical Engineering, South China University
of Technology, Wushan
Road - 381, Guangzhou 510641, People’s Republic of China

Org. Lett., Article ASAP

DOI: 10.1021/acs.orglett.6b01390

Publication Date (Web): June 14, 2016

*minzhang@scut.edu.cn

Abstract

A
new benzylation protocol, enabling straightforward access to
β-benzylated quinolines, has been demonstrated. By employing readily
available [RuCl₂(p-cymene)]₂ as a catalyst and O₂
as a sole green oxidant, various 1,2,3,4-tetrahydroquinolines were
efficiently converted in combination with aryl aldehydes into desired
products in a step- and atom-economic fashion together with the
advantages of excellent functional group tolerance and chemoselectivity,
offering an important basis for the transformation of saturated N-heterocycles into functionalized N-heteroaromatics
via a dehydrogenative cross-coupling strategy. Mechanistic
investigations support that the reaction undergoes a
monodehydrogenation-triggered β-benzylation mode.

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