• 대한화학회지
• /
• 제37권2호
• /
• pp.228-236
• /
• 1993

Grignard 시약,CH_3$MgI와 브로모벤질과의 반응은 전자전달과정(SET)과 라디칼 이온쌍 중간체를 거쳐 생성되는 동종짝지음 생성물 bibenzyl을 주생성물로 이온성 공격에 의해 생성되는 교차짝지음 생성물, 에틸벤젠을 부생성물로 생성시키며 전이금속 불순물이 거의 제거된 순수 금속 Mg으로 CH_3$MgI을 제조하였을 때 그 비는 78:22이었다. 그러나 실험실용 금속 Mg을 사용하였을 때 그 비는 감소하여 67:33이었으며 이 비는 촉매량으로 첨가시킨 $FeCl_3$ 양의 증가로 더욱 감소되어 최고 20:80 비로 Fe 이온은 이온성 교차생성물, 에틸벤젠을 주생성물로 유도하였으며 이러한 반응결과는 좋은 수소원자주게로 디이소프로필 에테르를 디에틸 에테르 대신 용매를 사용하였을 때에도 큰 변화가 관찰되지 않았다. 이러한 관찰은 Grignard 시약과 유기할로겐 화합물이나 카르보닐 화합물과의 반응에서 촉매 양의 전이금속염이 전자전달과정 속도를 증가시켜 동종짝지음 이합체 생성물의 증가를 일으키는 보고와 반대의 경향을 보인다. 이러한 촉매량의 $FeCl_3$ 첨가가 CH_3$MgI의 이온성 공격의 증가와 그에 따른 교차짝지음 생성물의 증가로 유도하는 것은 브로모벤질과 반응 중 생성된 Fe 종과의 착화합물 형성에 의해 벤질탄소-브롬 결합이 CH_3$MgI의 탄소음이온 공격에 대해 반응성이 증가되는 것으로 설명하였다. 이러한 설명은 2-페닐-1-브로모에탄의 CH_3$MgI와의 반응연구에서 관찰된 반응성 결여가 뒷받침하고 있다.

• Bulletin of the Korean Chemical Society
• /
• 제9권2호
• /
• pp.111-112
• /
• 1988

• 약학회지
• /
• 제47권6호
• /
• pp.417-421
• /
• 2003

This paper describes a synthetic route to novel 2'-methyl and 4'-hydroxy carbocyclic nucleosides. The methyl group was successfully installed by carbonyl addition reaction of isopropenyl magnesium bromide followed by ring-closing metathesis and the hydroxy group was directly introduced from carbohydrate chiral template "D-lactose".ose".uot;.

• 대한화학회지
• /
• 제53권3호
• /
• pp.340-344
• /
• 2009

Phosphonitrillic chroride cyclic trimer 화합물을 $200{\sim}300\;{^{\circ}C}$ 하에 개환중합하여 선상 고분자를 얻 은 후 Grignard 시약 ($CH_2$=CH-MgBr)을 천천히 가하여 vinyl 기를 포함하는 polyphosphazene을 합성하였 으며, 이 폴리머를 HEMA(2-hydroxyethyl methacrylate)와 반응시켜 HEMA/vinyl-substituted polyphosphazene 을 얻었다. 이 고분자를 AIBN (azobisisobutyronitrile) 개시제 존재 하에서 교차결합제로 EGDMA(ethylene glycol dimethacrylate) 그리고 NVP (N-vinyl-pyrrolidone)을 혼합하여 공중합 시켰다. 얻어진 공중합체에 대한 측정 결과 산소투과율 (Dk/t)은 88로 측정되었으며, 함수율은 30.89% 그리고 가시광선 투과율은 87%로 나타났다. 이 자료로부터 이 공중합체가 우수한 콘택트렌즈 재료임을 발견하였다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
• /
• pp.1193-1197
• /
• 2006

The novel oligomers were synthesized by Grignard reaction, the suzuki coupling reaction, etc. The oligomers were characterized by Infrared (IR), Mass spectrometer (MS). Their thermal properties were investigated by differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA). The new oligomers showed high thermal stability above $300^{\circ}C$.

• Bulletin of the Korean Chemical Society
• /
• 제35권9호
• /
• pp.2649-2654
• /
• 2014

Synthesis of north-5'-methylbicyclo[3.1.0]hexyl adenine and hypoxanthine nucleosides with an ethenyl group at C3' position was successfully achieved by a highly facile method. Methylbicyclo[3.1.0]hexanone (${\pm}$)-7 with three contiguous chiral centers and its epimer (${\pm}$)-6 was remarkably simply constructed only by four steps involving a carbenoid insertion reaction in the presence of rhodium (II) acetate dimer as a metal catalyst, giving a correct relative stereochemistry of the generated three chiral centers. Due to steric hindrance from the concave face of the bicyclo[3.1.0]hexanone system, a Grignard reaction of (${\pm}$)-7 with ethenylmagnesium bromide showed exclusive diastereoselectivity towards the b-face. The Grignard reaction chemoselectively proceeded without reacting with ester functionality. Coupling reaction of glycosyl donor (${\pm}$)-11 with 6-chloropurine nucleobase afforded only the desired $N^9$-alkylated nucleoside without the formation of $N^7$-regioisomer. By the conventional method, 6-chloro group was converted into 6-amino and 6-hydroxy groups to give the desired adenine and hypoxanthine bicyclo[3.1.0]hexyl carbanucleosides with 3'-ethenyl group, respectively.

• Bulletin of the Korean Chemical Society
• /
• 제17권2호
• /
• pp.153-158
• /
• 1996

The synthesis of common skeleton of podosporin A and aureol was studied through cationic olefin cyclization as a key step. The generation of thermodynamic silyl enol ether or enol acetate under known conditions gave regioselectivity of 88:12. The enolate alkylation of 2,3-dimethylcyclohexanone with 2,5-dimethoxybenzyl bromide at the more substituted site via lithium enolate gave poor yield. In this case an organozincate or an ammonium enolate also proved to be ineffective or not practical in terms of yield. Side chain elongation of the substituted cyclohexanone 13 through Grignard reaction, Wittig reaction, or Shappiro reaction did not proceed because of steric hindrance and side reactions. However, Stille coupling reaction via enol triflate produced the desired product 18 in high yield. The advanced intermediate 22, which was efficiently synthesized from 18, produced 24 instead of the desired product under a cationic olefin cyclization condition, indicating that the cyclization occurred in a stepwise mannervia the organomercury intermediate 23.

• Bulletin of the Korean Chemical Society
• /
• 제10권4호
• /
• pp.366-368
• /
• 1989

The 3-formyl-2-cephem 4, available from 7-aminocephalosporanic acid has been converted to C-3 vinylic cephems. The reactions involved are the Grignard addition to 4, the conversion of the resulting alcohols to mesylates, and the elimination of the mesyl group by LiCl. When ethylmagnesium iodide is used, only 3-[(E)-1-propenyl] cephem is obtained, which is not easily available by conventional Wittig reaction.

• 약학회지
• /
• 제48권1호
• /
• pp.88-92
• /
• 2004

In this study; a series of 2',4'-doubly branched carbocyclic nucleosides (8,9,10) were synthesized from simple acyclic ketone derivative as starting material. The installation of the 4'-quaternary carbon needed was carried out using a 〔3,3〕-sigmatropic rearrangement. In addition, the introduction of a methyl group in the 2'-position was accomplished by Grig-nard reaction. Bis-vinyl was successfully cyclized using a Grubbs' catalyst II. The natural bases (adenine, cytosine, uracil) were efficiently coupled with the use of a Pd(0) catalyst. Although all the synthesized compounds were assayed against several viruses, only cytosine analogue 9 showed weak antiviral viral activity (EC$_{50}$=45.4 $\mu$M) against CoxB3 virus.s.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
• /
• pp.439-442
• /
• 2007

Novel blue materials based on anthracene derivatives were synthesized by Grignard reaction, the Suziki coupling reaction, etc. They showed excellent thermal stability and emitted bright blue light, which will been used for OLED and expected to obtain high efficiency and good color purity.