HETEROCYCLES

■ Contents

■ Congratulations on Your 80-Years Birthday to Professor Akira Suzuki

Yurii N. Bubnov*

*A.N.Nesmeyanov Institute of 0rganoelement Compounds, Russian Academy of Sciences, 28 Vavilova str. 119991-GSP-I, V-334, Moscow, Russia

■ Laudatio Suzuki Akira

Victor Snieckus*

*Department of Chemistry, Queen's University, Kingston, Ontario K6L 3N6, Canada

■ Curriculum Vitae of Akira Suzuki

*,

■ Organoboranes in Organic Syntheses Including Suzuki Coupling Reaction

Akira Suzuki*

*3-2-905, Aino-sato 2-Jo, 6-Chome, Kita-ku, Sapporo, 002-8072, Japan

■ List of Publications by Akira Suzuki (1967-2008)
(Only publications concerned with the organoborane chemistry)

*,

■ A New Type of Oxidation-Reduction Condensation by the Combined Use of Phenyl Diphenylphosphinite and Oxidant

Teruaki Mukaiyama,* Kiichi Kuroda, and Yuji Maruyama

*Tokyo Chemical Industry Co., Ltd., 6-15-5 (TCI) Toshima, Kita-ku, Tokyo 114-0003, Japan

Abstract

A new type of oxidation−reduction condensation of alcohols with sulfur, nitrogen, and oxygen nucleophiles by the combined use of phenyl diphenylphosphinite (PhOPPh2) and oxidants such as azides or diethyl azodicarboxylate (DEAD) are described. In these reactions, chiral secondary and tertiary alcohols are converted into the corresponding chiral sulfides, azides, esters and ethers under mild and neutral conditions with almost complete inversion of stereochemical configuration.

■ Pharmaceutical Studies on Vitamin D Derivatives and Practical Syntheses of Six Commercially Available Vitamin D Derivatives That Contribute to Current Clinical Practice

Noboru Kubodera*

*Chugai Pharmaceutical Company, Ltd., 2-1-1, Nihonbashi-Muromachi, Chuo-ku, Tokyo 103-8324, Japan

Abstract

Three milestones exist in vitamin D research from the perspective of pharmaceutical development. The article first discusses the various milestones outlining vitamin D and derivatives in terms of pharmaceutical applications. Several active vitamin D derivatives based on the findings during the third milestone are now commercially available and contributing to current clinical practice. The paper also reviews the practical syntheses of six derivatives, maxacalcitol, calcipotriol, tacalcitol, paricalcitol, doxercalciferol, and falecalcitriol, as well as summarizes future prospects for further drug development.

■ Efforts toward the Synthesis of Pseudolaric Acid A: Intramolecular Bromoetherification as a Multipurpose Synthetic Tool

Jeremy D. Pettigrew and Leo A. Paquette*

*Evans Chemical Laboratories, The Ohio State University, 120 W. 18th Avenue, Columbus, Ohio 43210, U.S.A.

Abstract

Regioselective double bond cleavage within 5, required for access to the trans-fused perhydroazulene framework of pseudolaric acid A (1), has been accomplished via a highly diastereoselective intramolecular bromoetherification process, the latter serving a dual role as a protecting group tactic.

■ Construction of Fused Thiophene Ring System via Intramolecular CH Arylation by Palladium Catalysis

Atsunori Mori,* Nobumichi Arai, Tomomi Hatta, and Daiki Monguchi

*Department of Chemical Science and Engineering, Faculty of Engineering, Kobe University, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan

Abstract

Intramolecular CH arylation of a thiophene derivative in the presence of a palladium catalyst furnishes fused tricyclic thiophene in a high yield. The obtained thiophene undergoes further intermolecular CH arylation with a palladium catalyst and AgNO3/KF.

■ Solid Guests in Reversible Encapsulation Hosts

Dariush Ajami, and Julius Rebek, Jr.*

*Department of Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, U.S.A.

Abstract

The space inside a cylindrical capsule host is probed with a series of adamantane guests. The results indicate that higher packing coefficients are possible for solid guests than for liquids or gases in encapsulation complexes.

■ Mild and Selective O-Glycosylations of Primary Alcohols with the Thioglucosaminide Derivative Promoted by N-Iodosuccinimide and HBF4-Adosrobed on Silica Gel

Michio Kurosu* and Kai Li

*Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 1682 Campus Delivery, Fort Colllins, CO 80523-1682, U.S.A.

Abstract

Selective glycosylations of primary alcohols with the thioglucosaminide 1 are achieved by using NIS and HBF4-SiO2. HBF4-SiO2 is a mild Brønsted acid which requires primary alcohols or phenols to effectively activate 1 with NIS at rt. A wide range of functional groups are tolerated under these conditions.

■ Stereoselective Synthesis of α-Methylene-γ-butyrolactams from Ethyl 2-(Bromomethyl)acrylate and Chiral Sulfinyl Aldimines Mediated by Indium

Haythem K. Dema, Francisco Foubelo,* and Miguel Yus*

*Department of Organic Chemistry, Faculty of Sciences and Institute of Organic Synthesis (ISO), University of Alicante, P.O. Box 99, 03080 Alicante, Spain

Abstract

The reaction of ethyl 2-(bromomethyl)acrylate (1) with chiral N-tert-butylsulfinyl aldimines 2 and indium powder in THF at 100 ºC for 48 h affords, after hydrolysis, a mixture of N-tert-butylsulfinyl aminoesters 3 and α-methylene-γ-butyrolactams 4. From the reaction mixture, compounds 3 were quantitatively converted to the expected butyrolactams 4 after removal of the tert-butylsulfinyl group under acidic conditions and final basic workup. The whole process takes place in high overall yields and with fairly good stereoselectivities.

■ A New Entry for Preparation of 2-Substituted Azaindoles

Montaser Shaykoon Ahmed Shaykoon, Fuyuhiko Inagaki, and Chisato Mukai*

*Division of Pharmaceutical Sciecnes, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan

Abstract

A series of 2-substituted 5-, 6- and 7-azaindoles were synthesized from iodo-N-(tert-butoxycarbonyl)aminopyridines via the corresponding allenyl derivatives.

■ Asymmetric Hydrogenation of Aromatic Heterocyclic Ketones Catalyzed by the MsDPEN–Cp*Ir(III) Complex

Noriyuki Utsumi, Kunihiko Tsutsumi, Masahiko Watanabe, Kunihiko Murata, Noriyoshi Arai, Nobuhito Kurono, and Takeshi Ohkuma*

*Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0828, , Japan

Abstract

Asymmetric hydrogenation of aromatic heterocyclic ketones catalyzed by Cp*Ir(OTf)(Msdpen) (MsDPEN = N-(methanesulfonyl)-1,2-diphenylethylenediamine) affords the heterocyclic alcohols in 93% to >99% ee. The reaction is conducted in a methanolic solution with a substrate-to-catalyst molar ratio of 200–5000 under 15 atm of H2. The heterocyclic rings of substrates are left intact.

■ Phenanthrene-4,5-diylbis(10-methylacridinium) with a Short C+ - - C+ Contact: Preparation, Molecular Structure, Redox Properties, and Electrochromic Interconversion with Dihydropyrene Derivative

Takanori Suzuki,* Yasuyo Yoshimoto, Kazuhisa Wada, Takashi Takeda, Hidetoshi Kawai, and Kenshu Fujiwara

*Division of Chemistry, Graduate School of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810, Japan

Abstract

The title dication (12+) was generated by oxidative bond cleavage of a 4,5-dihydoropyrene derivative (2) with two spiro(10-methylacridan) units. Despite the skewed deformation of the arylene spacer, two cationic chromophores in 12+ are forced to face in a proximity with a very short interatomic separation of 2.98(1) Å between carbenium centers (X-ray), which makes the LUMO level of 1 much lower than that of biphenyl-2,2'-diyl-type dication (32+).

■ Highly Active Rhodium Catalyst with Electron-Poor Diphosphine Enables Efficient Synthesis of Chiral 4-Aryl-δ-lactones

Toshinobu Korenaga,* Ryota Maenishi, Kazutaka Osaki, and Takashi Sakai*

*Department of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University, 1-1-1 Tsushima-naka, Okayama 700-8530, Japan

Abstract

Chiral 4-aryl-δ-lactones could be synthesized efficiently with high enantioselectivity through asymmetric 1,4-addition of arylboronic acid to α,β-unsaturated lactones using Rh catalyst including electron-poor diphosphine (MeO-F12-BIPHEP) at room temperature for 1 h. In particular, our catalytic system proved to be applicable to relatively large coumarin analogues, giving optically pure 4-phenylchroman-2-one analogues in a short time.

■ Rhodium-Catalyzed 1,2-Addition of Sb-Phenyl-1,5-azastibocines to Functionalized Aldehydes

Naoki Kakusawa, Shuji Yasuike, and Jyoji Kurita*

*Faculty of Pharmaceutical Sciences, Hokuriku University, 3-Ho, Kanagawa machi, Kanazawa 920-1181, Japan

Abstract

Simple and efficient addition of a phenyl group to aldehydes was accomplished by the rhodium-catalyzed reaction of Sb-phenyl-1,5-azastibocines. Because of the soft nucleophilic character of 1,5-azastibocines, arylation of functionalized aldehydes having ketone, ester, and halogen moieties can be achieved to afford aryl alcohols. The reaction can be carried out under aerobic conditions, in striking contrast to the reactions with hard nucleophiles such as organolithium and Grignard reagents.

■ An Effective Kinetic Resolution of Racemic Secondary Benzylic Alcohols Using 3-Pyridinecarboxylic Anhydride and a Chiral Acyl-Transfer Catalyst in the Absence of Tertiary Amine

Kenya Nakata and Isamu Shiina*

*Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, Kagurazaka 1-3, Shinjuku-ku, Tokyo 162-8601, Japan

Abstract

3-Pyridinecarboxylic anhydride (3-PCA) was found to function as an efficient coupling reagent for the kinetic resolution of racemic secondary benzylic alcohols with achiral carboxylic acids in the presence of a catalytic amount of (+)-BTM. A variety of optically active carboxylic esters are produced with high enantiomeric excesses by this new chiral induction system without using a tertiary amine.

■ Preparation of 2-Sulfonyl-1,2,3-triazoles by Base-Promoted 1,2-Rearrangement of a Sulfonyl Group

Motoshi Yamauchi, Tomoya Miura, and Masahiro Murakami*

*Departmene of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, youdai-katsura, Nishikyo, Kyoto 615-8510, Japan

Abstract

1,2-Rearrangement of a sulfonyl group occurs on treatment of 1-sulfonyl-1,2,3-triazoles with a catalytic amount of 4-dimethylaminopyridine (DMAP) in acetonitrile to give an equilibrium mixture of 1-sulfonyl- and 2-sulfonyl derivatives, with considerable predominance of the latter. Subsequent acidic treatment of the mixture caused selective hydrolysis of the 1-sulfonyl derivative, which led to the isolation of the 2-sulfonyl-1,2,3-triazole in good total yield in a pure form.

■ Photolytic Preparation of Tetrabromothianthrene and Its Transformation to Dinuclear Phthalocyanines

Takeshi Kimura,* Takeru Obonai, Takayuki Nozaki, Kenji Matsui, Toshiharu Namauo, Akio Yamakawa, and Yutaka Takaguchi

*Center for Instrumental Analysis, Iwate University, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan

Abstract

Photolysis of dibromobenzotrithiole (1) and tetrabromodibenzo-tetrathiocin (4) in CH2Cl2 produced tetrabromothianthrene (2). Compound (2) was treated with CuCN in DMF at 150 °C to give tetracyanothianthrene (5). Dinuclear phthalocyanine (9) was constructed by treatment of a mixture of 5 and dioctoxyphthalonitrile (6) with lithium in n-pentanol.

■ Synthesis of Functionalized Chromanes via a Formal [3+3]Cycloaddition of Allene Sulfonamides to Phenols

Ken Hashimoto, Yoshikazu Horino,* and Shigeyasu Kuroda*

*Department of Applied Chemistry, Faculty of Engineering, Toyama University, Gofuku 3190, Toyama 930-8555, Japan

Abstract

The Brønsted acid catalyzed formal [3 + 3] cycloaddition reaction of allene sulfonamides 1 with phenols 2 provides functionalized chromanes. This formal [3 + 3] cycloaddition reaction is proposed to proceed via a stepwise process involving intermolecular hydroarylation followed by intramolecular cyclization.

■ Substituent Effects on the Electron Transfer-Initiated Photochemical Transformation of 1,2,4-Triazole-substituted α-Dehydroarylalaninamides into 2(1H)-Quinolinone Derivatives

Yuichi Yazawa, Minoru Suzuki, Tetsutaro Igarashi, and Tadamitsu Sakurai*

*Material and Life Chemistry, Faculty of Engineering, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan

Abstract

An investigation was undertaken to elucidate substituent effects on the photoreactivity of 1,2,4-triazole-substituted α-dehydroarylalaninamides [(Z)-1] as well as on the selectivity of 2(1H)-quinolinone derivatives (2) from a synthetic point of view. It was found that photoinduced electron transfer-initiated cyclization of (Z)-1 bearing a meta-substituted phenyl or a 4-substituted naphthalen-1-yl group in methanol proceeds with a moderate to good efficiency affording the corresponding product 2 in a selectivity ranging from 33 to 100%.

■ A Hetero Pauson-Khand Reaction of Ketenimines: A New Synthetic Method for γ-Exomethylene-α,β-unsaturated γ-Lactams

Takao Saito,* Katsuya Sugizaki, Hiroyuki Osada, Noriki Kutsumura, and Takashi Otani

*Department of Chemistry, Faculty of Science, Science University of Tokyo, Kagurazaka 1-3, Shinjuku-ku, Tokyo 162-8601, Japan

Abstract

A novel ketenimine Pauson–Khand reaction has been described for the first time. C,C,N-Triarylketenimines reacted with alkyne–dicobalthexacarbonyl complexes upon heating in toluene in the presence of dimethyl sulfoxide as a promoter to afford γ-lactams, 5-(diphenylmethylene)-1H-pyrrol-2(5H)-ones, in good yields.

■ Palladium- or Nickel-Catalyzed Coupling Reaction of Dialkoxyboranes with Chloroarenes: Arylation of 1,3,2-Dioxaborolanes or 1,3,2-Dioxaborinanes

Miki Murata,* Tomoko Sambommatsu, Takeshi Oda, Shinji Watanabe, and Yuzuru Masuda

*Faculty of Engineering Department of Materials Science and Engineering, Kitami Institute of Technology, Koen-cho 165, Kitami, Hokkaido 090-8507, Japan

Abstract

The borylation of electron-deficient aryl chlorides with pinacolborane proceeded in the presence of Bu4NI and a catalytic amount of Pd(dba)2 / bis(2-di-tert-butylphosphinophenyl) ether. The combination of NiCl2(dppp) catalyst and Bu4NBr was also efficient for the borylation of aryl chlorides.

■ Stereoselective Formal Total Synthesis of Novel Antibiotic (-)-Centrolobine

Debendra K. Mohapatra,* Rita Pal, Hasibur Rahaman, and Mukund K. Gurjar

*Organic Chemistry Division I, Indian Institute of Chemical Technology, Hyderabad-500 007, India

Abstract

A concise and stereoselective formal total synthesis of (−)-centrolobine is achieved utilizing Mioskowski’s Lewis acid mediated epoxide opening followed by ring-closing metathesis as the key reaction.

■ Enantioselective Total Synthesis of Novel Diterpenoid Pyrones (+)-Sesquicillin and (-)-Nalanthalide from Fungal Fermentations

Takamasa Oguchi, Kazuhiro Watanabe, Hideki Abe, and Tadashi Katoh*

*Department of Synthetic Organic Chemistry, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan

Abstract

We efficiently synthesized (+)-sesquicillin (a glucocorticoid antagonist) and (–)-nalanthalide (a potassium channel Kv1.3 blocker) in a convergent and unified manner starting from (+)-5-methyl-Wieland–Miescher ketone. The synthesis involved the following key steps: (i) a [2,3]-Wittig rearrangement of a stannylmethyl ether to install the stereogenic center at C9 and the exo-methylene functionality at C8 present in the trans-decalin portion, (ii) a coupling reaction of a trans-decalin portion with a γ-pyrone moiety to assemble the requisite whole carbon framework, and (iii) a conversion of a γ-pyrone moiety to an α-pyrone ring to produce (+)-sesquicillin. The present total synthesis has verified the absolute configuration of these natural products.

■ Synthesis of 4-Azachromeno[2,3-b]indol-11(6H)-one and Its Derivatives as Analogues of Ellipticine

Yanhong Chen, Chunhao Yang,* and Yuyuan Xie*

*State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, SIBS, Chinese Academy of Science, 555 Zu Chong Zhi Road, Shanghai 201203, China

Abstract

4-Azachromeno[2,3-b]indol-11(6H)-ones (4) and their derivatives (5) as analogues of ellipticine were synthesized through a straightforward, two or three-step process. Tetracyclic heterocycles (4) were obtained by facile cyclization of indolin-2-ones (2) or (3) and 2-chloronicotinoyl chloride under the condition of the ‘Jensen’-reaction. Alkylation of the compounds (4) afforded 6-substituted 4-azachromeno[2,3-b]indol-11(6H)-ones.

■ Tin-Hydride-Mediated Radical Addition of Alkyl Halides to 2-Methylene-1,3-dithiane Monoxide as a Ketene Equivalent

Suguru Yoshida, Hideki Yorimitsu,* and Koichiro Oshima*

*Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan

Abstract

Reductive radical addition of alkyl halides to ketene dithioacetal monoxide in the presence of tributyltin hydride and a radical initiator provides the corresponding adducts, 2-alkyl-1,3-dithiane monoxides, in good yields.

■ Synthesis of 4-Aryl-Substituted Butenolides and Pentenolides by Copper-Catalyzed Hydroarylation

Yoshihiko Yamamoto* and Naohiro Kirai

*Graduate School of Engineering, Nagoya University, Chikusa, Nagoya, Aichi 464-8601, Japan

Abstract

We have investigated the effect of the type of protecting group used and the tether length of 4- and 5-hydroxy-substituted 2-alkynoates on the yields and selectivity of the product of hydroarylation. The use of methyl, methoxymethyl, and tert-butyldimethylsilyl (TBS) as protecting groups increased the total yield of the products. While the protected 4-hydroxy-2-butynoates afforded products formed from two or more alkyne substrates, 5-hydroxy-2-pentynoate derivatives exclusively yielded 1:1 adducts. These facts suggest that the product selectivity depends on the distance of the alkoxy group from the alkyne moiety rather than the type of the protecting group. Among the protecting groups used in this study, the TBS group was found to produce butenolides and pentenolides in good total yields via the one-pot hydroarylation/lactonization.