九州大学 · Chemistry
오시마 타카시 교수의 연구실은 주로 촉매화학과 유기합성화학을 중심으로, 고화학선택성과 고자기선택성을 실현하는 새로운 촉매 체계 개발에 중점을 두고 있습니다. 특히 아미노산 衍생체의 비대칭 합성, 알코올 및 아민의 선택적 아실화, 플라티넘 기반 촉매를 이용한 직접 아미네이션 반응 등에서 혁신적인 성과를 내고 있으며, 환경 친화적이고 원자 효율적인 반응 조건의 구축에도 기여하고 있습니다. 이는 합성 화학의 지속 가능성과 약물 합성 응용에 기여하는 핵심 연구 분야입니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Acylation of alcohols and amines is one of the most fundamental reactions. Due to the greater nucleophilicity of the amino group compared to the hydroxyl group, complete N-acylation occurs. Only an enzymatic reaction can promote a highly selective O-acylation reaction, and there are no examples using an artificial catalyst. Here we report that the tetranuclear zinc cluster Zn4(OCOCF3)6O efficiently catalyzes highly chemoselective O-acylation in the presence of primary and secondary alkyl amines.
Transition metal-catalyzed amination of allylic compounds via a pi-allylmetal intermediate is a powerful and useful method for synthesizing allylamines. Direct catalytic substitution of allylic alcohols, which forms water as the sole coproduct, has recently attracted attention for its environmental and economical advantages. Here, we describe the development of a versatile direct catalytic amination of both aryl- and alkyl-substituted allylic alcohols with various amines using Pt-Xantphos and Pt
Optically active α,β-diamino acids are prepared under asymmetric phase-transfer reaction conditions from a glycine Schiff base and N-protected imines with a tartrate-derived diammonium salt (TaDiAS) as the phase-transfer catalyst (see scheme; Boc=tert-butoxycarbonyl). Chemoselective deprotection of the N atoms allows straightforward transformations of the α,β-diamino acid products to be carried out.
An asymmetric Heck reaction−carbanion capture process was realized for the first time, making possible the catalytic asymmetric synthesis of various functionalized bicyclo[3.3.0]octane derivatives 6 in up to 94% ee. Sodium bromide had interesting effects on this asymmetric Heck reaction−carbanion capture process, and these effects were useful for improving the enantiomeric excess. Furthermore, the catalytic asymmetric synthesis of (−)-Δ9(12)-capnellene (7) was achieved for the first time, using
The enantioselective total synthesis of (-)-strychnine was accomplished through the use of the highly practical catalytic asymmetric Michael reaction (0.1 mol % of (R)-ALB, more than kilogram scale, without chromatography, 91% yield and >99% ee) as well as a tandem cyclization that simultaneously constructed B- and D-rings (>77% yield). Moreover, newly developed reaction conditions for thionium ion cyclization, NaBH3CN reduction of the imine moiety in the presence of Lewis acid to prevent ring o
A simple NaOMe catalyst provides superior accessibility to a wide variety of functionalized amides including peptides through direct amination of esters in an atom-economical and environmentally benign way.
Thinking outside the box: A newly developed C1-symmetric Rh/Phebox complex efficiently catalyzed the asymmetric alkynylation of α-ketoester 1 with various aryl and alkyl substituted terminal alkynes to provide the corresponding chiral tertiary propargylic alcohols with up to 99 % ee (see scheme; TMS=trimethylsilyl).
Direct amination of unactivated allylic alcohols with aqueous ammonia was catalyzed by a Pt/phosphine complex to give the corresponding allylamines along with water as the sole by-product. Under optimized reaction conditions, primary allylamines were obtained as major products with excellent monoallylation selectivity. cod=1,5-cyclooctadiene. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or type
