Hydroboration. 86. Convenient conversion of aldehydes and ketones into the corresponding alkenes via hydroboration of their enamines. A remarkably simple synthesis of either (Z)- or (E)-alkenes
摘要:
Aldehydes and ketones are converted into the corresponding alkenes via hydroboration of their enamines. Hydroboration of aldehyde enamines by 9-borabicyclo[3.3.1]nonane (9-BBN), followed by methanolysis, affords the corresponding terminal alkenes in 75-90% yields. Unsaturated aldehyde enamines produce the corresponding dienes under these conditions. Enamines derived from substituted cyclic ketones and heterocyclic ketones are readily accommodated in this reaction to afford the corresponding alkenes in very good yields. The synthesis of pure (Z)- or (E)-alkenes is readily achieved from the same acyclic ketone enamine by modification of the hydroboration-elimination procedure: (A) hydroboration by 9-BBN followed by methanolysis or (B) hydroboration by borane methyl sulfide (BMS) followed by methanolysis and hydrogen peroxide oxidation. Mechanistic rationale is provided.
Direct Olefination of Alcohols with Sulfones by Using Heterogeneous Platinum Catalysts
作者:S. M. A. Hakim Siddiki、Abeda Sultana Touchy、Kenichi Kon、Ken-ichi Shimizu
DOI:10.1002/chem.201505109
日期:2016.4.18
catalysts for the direct Julia olefination of alcohols in the presence of sulfones and KOtBu under oxidant‐free conditions. Primary alcohols, including aryl, aliphatic, allyl, and heterocyclic alcohols, underwent olefination with dimethyl sulfone and aryl alkyl sulfones to give terminal and internal olefins, respectively. Secondary alcohols underwent methylenation with dimethyl sulfone. Under 2.5 bar
发现在无氧化剂条件下,在砜和KO t Bu存在的情况下,碳负载的Pt纳米颗粒(Pt / C)是有效的多相催化剂,可直接用于醇的Julia烯化反应。伯醇,包括芳基,脂族,烯丙基和杂环醇,分别与二甲基砜和芳基烷基砜进行烯烃化反应,分别得到末端烯烃和内部烯烃。仲醇与二甲基砜进行亚甲基化。在2.5 bar H 2下,相同的反应体系对于将醇OH基团转化为烷基基团是有效的。末端烯烃化系统的结构和机理研究表明Pt 0Pt金属颗粒上的两个位点是限制醇脱氢速率的原因,而KO t Bu可能会使砜试剂脱质子。Pt / C催化剂在烯化后可重复使用,与以前报道的方法相比,该方法显示出更高的周转数(TON)和更宽的底物范围,这证明了本方法的高催化效率。
Biocatalytic Cleavage of Alkenes with O<sub>2</sub>and<i>Trametes hirsuta</i>G FCC 047
作者:Miguel Lara、Francesco G. Mutti、Silvia M. Glueck、Wolfgang Kroutil
DOI:10.1002/ejoc.200800261
日期:2008.7
Alkenes possessing a C=C double bond adjacent to an aromatic ring were cleaved to yield the corresponding carbonyl compounds by use of molecular oxygen as the sole oxidant and a cell-free extract of the wood-degrading fungus Trametes hirsuta FCC047 as catalyst. The oxygen pressure required was optimized. Special adapted equipment allowed 96 reactions to be performed in parallel under controlled oxygen
Direct catalytic cross-coupling of organolithium compounds
作者:Massimo Giannerini、Martín Fañanás-Mastral、Ben L. Feringa
DOI:10.1038/nchem.1678
日期:2013.8
carbon–carbon bond formation based on cross-coupling reactions plays a central role in the production of natural products, pharmaceuticals, agrochemicals and organic materials. Coupling reactions of a variety of organometallic reagents and organic halides have changed the face of modern synthetic chemistry. However, the high reactivity and poor selectivity of common organolithium reagents have largely prohibited
Angiotensin II receptor antagonists having the formula:
which are useful in regulating hypertension and in the treatment of congestive heart failure, renal failure, and glaucoma, pharmaceutical compositions including these antagonists, and methods of using these compounds to produce angiotensin II receptor antagonism in mammals.
式的血管紧张素 II 受体拮抗剂:
用于调节高血压和治疗充血性心力衰竭、肾功能衰竭和青光眼的血管紧张素 II 受体拮抗剂,包括这些拮抗剂的药物组合物,以及使用这些化合物在哺乳动物体内产生血管紧张素 II 受体拮抗作用的方法。
Fragrance materials
申请人:TAKASAGO INTERNATIONAL CORPORATION
公开号:US11236288B2
公开(公告)日:2022-02-01
The synthesis and application of a compound having unique and desired fragrance characteristics is provided herein. The compound of the present disclosure can be employed alone or incorporated as a fragrance component in fragrance compositions. The application is also directed to consumer products comprising such compound and/or fragrance compositions.