Bifunctional Lewis Base Catalysis with Dual Activation of R–M and C–O (n –> σ*)
Manabu Hatano and Kazuaki Ishihara
In Lewis Base Catalysis in Organic Synthesis, 3 Volumes Set, edited by Edwin Vedejs and Scott E. Denmark, 2016, p. 339–386, Wiley-VCH, August 2016. ISBN: 978-3-527-33618-0
▼Regioselective 1,4- and 1,6-Conjugate Additions of
Grignard Reagent-Derived Organozinc(II)ates to Polyconjugated Esters
Manabu Hatano, Mai Mizuno, and Kazuaki Ishihara*
Org. Lett. 2016, 18(18), 4462-4465.
Publication Date (Web): September 7, 2016 (Letter)
Regioselective synthetic methods were developed for 1,4- and 1,6-conjugate additions of Grignard reagent-derived organozinc(II)ates to malonate-derived polyconjugated esters. By taking advantage of the tight ion-pair control of organozinc(II)ates, it was possible to switch between 1,4- and 1,6-conjugate additions by introducing a terminal ethoxy moiety in the conjugation.
化学工業 2016, 67(9), 660–667.
Asymmetric Dearomatization Reactions
Chapter 6. Asymmetric Oxidative Dearomatization Reaction
Muhammet Uyanik and Kazuaki Ishihara, pp. 129-151
In "Asymmetric Dearomatization Reactions" edited by Shu-Li You
[ISBN: 978-3-527-33851-1], 424 pages, Wiley-VCH, August 2016.
[From Biosynthesis to Total Synthesis: Strategies and Tactics for Natural Products]
Alexandros L. Zografos
584 pages, Wiley, April 2016, ISBN: 978-1-118-75173-2
Chapter 9: Higher Terpenes and Steroids, pp. 296–330
▼Enantioselective Bromocyclization of 2-Gernaylphenols
Induced by Chiral Phosphite–Urea Bifunctional Catalysts
Yasuhiro Sawamura, Yoshihiro Ogura, Hidefumi Nakatsuji, Akira Sakakura* and Kazuaki Ishihara*
Chem. Commun. 2016, DOI: 10.1039/C6CC00229C
Chiral phosphite–urea bifunctional catalysts have been developed for the enantioselective bromocyclization of 2-geranylphenols with N-bromophthalimide (NBP) for the first time. The chiral triaryl phosphite moiety activates NBP to generate a bromophosphonium ion. On the other hand, the urea moiety interacts with a hydroxyl group of the substrate through hydrogen bonding interactions. Enantioselectivity is effectively induced through two-point attractive interactions between the catalyst and the substrate.
月刊ファインケミカル 2016年2月号 pp. 24–32.
▼Enantioselective Diels–Alder Reaction Induced by Chiral Supramolecular Lewis Acid Catalysts Based on CN···B and PO···B Coordination Bonds
Manabu Hatano, Kazushi Hayashi, Tatsuhiro Sakamoto, Yuma Makino, Kazuaki Ishihara*
Synlett, 2016, 27, 1061-1067. Web Publication Date: 05 February 2016
Chiral supramolecular boron Lewis acid catalysts were prepared from chiral 3-phosphoryl-1,1′-bi-2-naphthols, (2-cyanophenyl)boronic acids, and tris(pentafluorophenyl)borane, bound through CN···B and PO···B coordination bonds. In particular, the coordinated tris(pentafluorophenyl)boranes increase the Lewis acidity of the active center in the manner of a Lewis acid assisted Lewis acid catalyst system. A possible cavity in these catalysts was highly suitable for several Diels–Alder probe reactions of acroleins with cyclic or acyclic dienes, which gave the corresponding adducts in good to high yields and high enantioselectivities.
▼Enantioselective Cyanosilylation of Ketones with Lithium(I) Dicyanotrimethylsilicate(IV)
Catalyzed by a Chiral Lithium(I) Phosphoryl Phenoxide
Manabu Hatano, Katsuya Yamakawa, Tomoaki Kawai, Takahiro Horibe, Kazuaki Ishihara*
Angew. Chem. Int. Ed. 2016, 55(12), 4021-4025.
Article first published online: 2 FEB 2016.
A highly enantioselective cyanosilylation of ketones was developed by using a chiral lithium(I) phosphoryl phenoxide aqua complex as an acid/base cooperative catalyst. The pentacoordinate silicate generated in situ from Me3SiCN/LiCN acts as an extremely reactive cyano reagent. Described is a 30 gram scale reaction and the synthesis of the key precursor to (+)-13-hydroxyisocyclocelabenzine.
[Cover picture] Enantioselective Cyanosilylation of Ketones with Lithium(I) Dicyanotrimethylsilicate(IV) Catalyzed by a Chiral Lithium(I) Phosphoryl Phenoxide
Hatano, H.; Yamakawa, K.; Kawai, T.; Horibe, T.; K. Ishihara
Angew. Chem. Int. Ed. early view. DOI: 10.1002/anie.201601600
▼Chiral Ammonium Hypoiodite Salt-Catalyzed Enantioselective Oxidative
Cycloetherification to 2-Acyl Tetrahydrofurans
Muhammet Uyanik, Hiroki Hayashi, Hirokazu Iwata, and Kazuaki Ishihara
Chem. Lett. 2016, 45(3), 353–355.
2-Acyl tetrahydrofuran is a fundamental structure in natural products and pharmaceuticals. We achieved a chiral quaternary ammonium hypoiodite salt-catalyzed enantioselective oxidative cycloetherification of δ-hydroxyketone derivatives. The corresponding 2-acyl tetrahydrofurans were obtained in high chemical yield with high enantioselectivity.
Chapter 2. Alkali metal (Li, Na, K)-based Catalysts
Manabu Hatano and Kazuaki
pp. 15–48, RSC Green Chemistry No. 38, Sustainable Catalysis: With Non-endangered Metals, Part 1 Edited by Michael North
The Royal Society of Chemistry 2016
▼Structurally Defined Molecular Hypervalent Iodine Catalysts for
Intermolecular Enantioselective Reactions
S. Haubenreisser, T. H. Wöste, C. Martínez, K. Ishihara, K. Muñiz
Angew. Chem. Int. Ed. 2016, 55(1), 413–417. First published: 24 November 2015.
Molecular structures of the most prominent chiral non-racemic hypervalent iodine(III) reagents to date have been elucidated for the first time. The formation of a chirally induced supramolecular scaffold based on a selective hydrogen-bonding arrangement provides an explanation for the consistently high asymmetric induction with these reagents. As an exploratory example, their scope as chiral catalysts was extended to the enantioselective dioxygenation of alkenes. A series of terminal styrenes are converted into the corresponding vicinal diacetoxylation products under mild conditions and provide the proof of principle for a truly intermolecular asymmetric alkene oxidation under iodine(I/III) catalysis.
[Cover Picture] Structurally Defined Molecular Hypervalent Iodine Catalysts for Intermolecular Enantioselective Reactions
S. Haubenreisser, T. H. Wöste, C. Martínez, K. Ishihara, K. Muñiz Angew. Chem. Int. Ed. 2016, 55(1), 413–417.
▼Remote Tris(pentafluorophenyl)borane-Assisted Chiral Phosphoric Acid Catalysts for the Enantioselective Diels–Alder Reaction
Manabu Hatano, Hideyuki Ishihara, Yuta Goto, Kazuaki Ishihara*
Synlett, 2016, 27, 564-570.
Tris(pentafluorophenyl)borane-assisted chiral supramolecular phosphoric acid catalysts were developed for the model Diels–Alder reaction of α-substituted acroleins with cyclopentadiene. Two remotely coordinated tris(pentafluorophenyl)boranes should help to increase the Brønsted acidity of the active center in the supramolecular catalyst and create effective bulkiness for the chiral cavity. The prepared supramolecular catalysts acted as not only conjugated Brønsted acid–Brønsted base catalysts but also bifunctional Lewis acid–Brønsted base catalysts with the addition of a central achiral Lewis acid source such as catecholborane.
▼Boronic Acid–DMAPO Cooperative Catalysis for Dehydrative Condensation between Carboxylic Acids and
Kazuaki Ishihara and Yanhui Lu
Chem. Sci. 2016, 7, 1276–1280. Accepted Manuscript (Received 04 Oct 2015, Accepted 02 Nov 2015)
Arylboronic acid and 4-(N,N-dimethylamino)pyridine N-oxide (DMAPO) cooperatively catalyse the dehydrative condensation reaction between carboxylic acids and amines to give the corresponding amides under azeotropic reflux conditions. The cooperative use of them is much more effective than their individual use as catalyst, and chemoselectively promoted the amide condensation of (poly)conjugated carboxylic acids. The present method is readily practical and scalable, and has been applied to the synthesis of Sitagliptin and a drug candidate.