start-ver=1.4 cd-journal=joma no-vol= cd-vols= no-issue= article-no= start-page=e202510319 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2025 dt-pub=20250626 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Development of a Vinylated Cyclic Allene: A Fleeting Strained Diene for the Diels–Alder Reaction en-subtitle= kn-subtitle= en-abstract= kn-abstract=Fleeting molecules possessing strained multiple bonds are important components in organic synthesis due to their ability to undergo various chemical reactions driven by the release of strain energy. Although the use of strained π-bonds as 2π components, represented by dienophiles in Diels–Alder reactions, has been well studied, “the strained diene (4π component) approach” for molecular construction remains underexplored. Herein, we report the design of a vinyl cyclic allene (1-vinyl-1,2-cyclohexadiene) as a highly reactive strained diene and the development of its Diels–Alder reactions. Experimental and computational studies of vinyl cyclic allenes revealed that this diene system undergoes cycloaddition with dienophiles regio- and stereoselectively under mild reaction conditions. These studies also provide insight into the reactivity and selectivity of the system. The strained diene approach enables the convergent construction of polycyclic molecules through bond disconnections distinct from conventional retrosynthetic analysis, thus offering an efficient strategy for the assembly of functional molecules. en-copyright= kn-copyright= en-aut-name=MizoguchiHaruki en-aut-sei=Mizoguchi en-aut-mei=Haruki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=ObataTakumi en-aut-sei=Obata en-aut-mei=Takumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HiraiTaiki en-aut-sei=Hirai en-aut-mei=Taiki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KomatsuManaka en-aut-sei=Komatsu en-aut-mei=Manaka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=SakakuraAkira en-aut-sei=Sakakura en-aut-mei=Akira kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University kn-affil= affil-num=5 en-affil=Graduate School of Environmental, Life, Natural Science and Technology, Okayama University kn-affil= en-keyword=Activation strain model kn-keyword=Activation strain model en-keyword=Carbocycles kn-keyword=Carbocycles en-keyword=Diels–Alder reaction kn-keyword=Diels–Alder reaction en-keyword=Strained diene kn-keyword=Strained diene en-keyword=Vinylated cyclic allene kn-keyword=Vinylated cyclic allene END start-ver=1.4 cd-journal=joma no-vol=13 cd-vols= no-issue= article-no= start-page=9580 end-page=9585 dt-received= dt-revised= dt-accepted= dt-pub-year=2022 dt-pub=20220725 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Annulative coupling of vinylboronic esters: aryne-triggered 1,2-metallate rearrangement en-subtitle= kn-subtitle= en-abstract= kn-abstract=A stereoselective annulative coupling of a vinylboronic ester ate-complex with arynes producing cyclic borinic esters has been developed. An annulation reaction that proceeded through the formation of two C-C bonds and a C-B bond was realized by exploiting a 1,2-metallate rearrangement of boronate triggered by the addition of a vinyl group to the strained triple bond of an aryne. The generated aryl anion would then cyclize to a boron atom to complete the annulation cascade. The annulated borinic ester could be converted to boronic acids and their derivatives by oxidation, halogenation, and cross-coupling. Particularly, halogenation and Suzuki-Miyaura coupling proceeded in a site-selective fashion and produced highly substituted alkylboronic acid derivatives. en-copyright= kn-copyright= en-aut-name=MizoguchiHaruki en-aut-sei=Mizoguchi en-aut-mei=Haruki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KamadaHidetoshi en-aut-sei=Kamada en-aut-mei=Hidetoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MorimotoKazuki en-aut-sei=Morimoto en-aut-mei=Kazuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YoshidaRyuji en-aut-sei=Yoshida en-aut-mei=Ryuji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=SakakuraAkira en-aut-sei=Sakakura en-aut-mei=Akira kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=5 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=86 cd-vols= no-issue=14 article-no= start-page=9802 end-page=9810 dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=202177 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Toward the Synthesis of Paspaline-Type Indole-Terpenes: Stereoselective Construction of Core Scaffold with Contiguous Asymmetric Quaternary Carbon Centers en-subtitle= kn-subtitle= en-abstract= kn-abstract=The core scaffold of paspaline-type indole-terpenes was synthesized by using the House–Meinwald rearrangement as a key step. Rearrangement of the epoxide methyl group in the precursor with MABR (methylaluminum bis(4-bromo-2,6-di-tert-butylphenoxide)) as a Lewis acid proceeded smoothly to construct contiguous asymmetric quaternary carbon centers by a 1,2-chirality transfer. en-copyright= kn-copyright= en-aut-name=HayakawaIchiro en-aut-sei=Hayakawa en-aut-mei=Ichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MatsumaruNaochika en-aut-sei=Matsumaru en-aut-mei=Naochika kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=SakakuraAkira en-aut-sei=Sakakura en-aut-mei=Akira kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= affil-num=1 en-affil=Graduate School of Integrated Basic Sciences, Nihon University, 3-25-40 Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan kn-affil= END start-ver=1.4 cd-journal=joma no-vol=85 cd-vols= no-issue=2 article-no= start-page=798 end-page=805 dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20191218 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Formal Total Synthesis of Manzacidin B via Sequential Diastereodivergent Henry Reaction en-subtitle= kn-subtitle= en-abstract= kn-abstract=A formal total synthesis of manzacidin B is described. beta,beta-Disubstituted gamma-hydroxy-beta-aminoalcohol, the key structure of manzacidin B, is stereoselectively constructed via sequential Henry reactions. By taking advantage of noncovalent interactions, such as intramolecular hydrogen bonding and chelation, we could diastereodivergently control the stereoselectivity of the Henry reaction. en-copyright= kn-copyright= en-aut-name=ArakiYuya en-aut-sei=Araki en-aut-mei=Yuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MiyoshiNatsumi en-aut-sei=Miyoshi en-aut-mei=Natsumi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MorimotoKazuki en-aut-sei=Morimoto en-aut-mei=Kazuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KudohTakayuki en-aut-sei=Kudoh en-aut-mei=Takayuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MizoguchiHaruki en-aut-sei=Mizoguchi en-aut-mei=Haruki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=SakakuraAkira en-aut-sei=Sakakura en-aut-mei=Akira kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=5 en-affil=Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=6 en-affil=Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=21 cd-vols= no-issue=7 article-no= start-page=2073 end-page=2076 dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20190312 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Thioureas as Highly Active Catalysts for Biomimetic Bromocyclization of Geranyl Derivatives en-subtitle= kn-subtitle= en-abstract= kn-abstract= Thioureas bearing electron-deficient aryl groups show high catalytic activity in the biomimetic bromocyclization of geranyl derivatives. The reaction of geranyl derivatives with N-bromosuccinimide (NBS) proceeds rapidly in CH2Cl2 to give the corresponding bromocyclization products in high yields as a ca. 1:1 mixture of endo- and exo-isomers. The reactivity of geranyl derivatives highly depends on the terminal substituent: electron-donating substituents increase the reactivity, while electron-withdrawing substituents decrease the reactivity. en-copyright= kn-copyright= en-aut-name=TerazakiMiyuki en-aut-sei=Terazaki en-aut-mei=Miyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=ShiomotoKei-ichi en-aut-sei=Shiomoto en-aut-mei=Kei-ichi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=MizoguchiHaruki en-aut-sei=Mizoguchi en-aut-mei=Haruki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SakakuraAkira en-aut-sei=Sakakura en-aut-mei=Akira kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=55 cd-vols= no-issue=27 article-no= start-page=3923 end-page=3926 dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20190407 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Catalytic enantioselective Hosomi-Sakurai reaction of α-ketoesters promoted by chiral copper(ii) complexes en-subtitle= kn-subtitle= en-abstract= kn-abstract= A catalytic enantioselective Hosomi–Sakurai reaction of α-ketoesters has been developed. A copper(II) complex with a chiral bis(oxazoline) ligand bearing methanesulfonamide groups shows excellent catalytic activity to give α,α-disubstituted α-hydroxyesters in high yields with high enantioselectivities. This is the first successful method for the catalytic enantioselective 1,2-addition of α-ketoesters with allylic silanes. en-copyright= kn-copyright= en-aut-name=NiwaYutaro en-aut-sei=Niwa en-aut-mei=Yutaro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MiyakeMayu en-aut-sei=Miyake en-aut-mei=Mayu kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=HayakawaIchiro en-aut-sei=Hayakawa en-aut-mei=Ichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SakakuraAkira en-aut-sei=Sakakura en-aut-mei=Akira kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=30 cd-vols= no-issue=15 article-no= start-page=1835 end-page=1839 dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20190917 dt-online= en-article= kn-article= en-subject= kn-subject= en-title=Enantioselective 1,3-Dipolar Cycloaddition Reaction of Nitrones with α-(Acyloxy)acroleins Catalyzed by Dipeptide-Derived Chiral Tri- or Diammonium Salts kn-title=Dipeptide-Derived Chiral Tri- or Diammonium Salt-Catalyzed Enantioselective 1,3-Dipolar Cycloaddition Reaction of Nitrones with a- (Acyloxy)acroleins en-subtitle= kn-subtitle= en-abstract= kn-abstract= Organoammonium salts of dipeptide-derived chiral tri-amines or diamines with TfOH catalyzed the enantioselective 1,3-dipolar cycloaddition reactions of alpha-acyloxyacroleins with nitrones to give the corresponding adducts in good yields (up to 96%) and with high diastereo- and enantioselectivities (up to 89% ee). Although alpha-(p-methoxybenzoyloxy)acrolein is rather unstable under the reaction conditions, alpha-(3-pyrroline-1-carbonyloxy)acrolein is stable enough to be smoothly converted into the corresponding adducts with the aid of the chiral organoammonium salt catalysts. en-copyright= kn-copyright= en-aut-name=KidouChihiro en-aut-sei=Kidou en-aut-mei=Chihiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=Mizoguchi Haruki en-aut-sei=Mizoguchi  en-aut-mei=Haruki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NehiraTatsuo en-aut-sei=Nehira en-aut-mei=Tatsuo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SakakuraAkira en-aut-sei=Sakakura en-aut-mei=Akira kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Integrated Sciences for Life, Hiroshima University kn-affil= affil-num=4 en-affil=Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=acyloxyacroleins kn-keyword=acyloxyacroleins en-keyword=1,3-dipolar cycloaddition kn-keyword=1,3-dipolar cycloaddition en-keyword=isoxazolidines kn-keyword=isoxazolidines en-keyword=nitrones kn-keyword=nitrones en-keyword=organocatalysis kn-keyword=organocatalysis en-keyword=asymmetric catalysis kn-keyword=asymmetric catalysis END