Stereoselective Aldol-Type Cyclization Reaction Mediated by Dibutylboron Triflate/Diisopropylethylamine
作者:Sanjib Das、Lian-Sheng Li、Subhash C. Sinha
DOI:10.1021/ol036229b
日期:2004.1.1
[reaction: see text] Dibutylboron triflate/diisopropylethylamine mediated aldol-type cyclization provides an expedient route for the stereoselective synthesis of cyclic ethers in a single step. The method is highly efficient for the stereoselective synthesis of 4-cis-tetrahydropyranones. The reaction is proposed to proceed via an S(N)1-type mechanism through a chair-like transition state, in which
False identity: The synthesis of a natural product described by Faulkner and co‐workers two decades ago has revealed the need for the revision of some stereochemical assignments. The key steps in this flexible route, which could provide access to stereodefined analogues for biological evaluation, included a Julia coupling, a Suzuki–Miyaura reaction, and Wittig olefination (see scheme; MOM, PMB, and
Efficient, divergent synthesis of cryptophycin unit A analogues
作者:Kyle L. Bolduc、Scott D. Larsen、David H. Sherman
DOI:10.1039/c2cc32417b
日期:——
A flexible and divergent synthesis of cryptophycin unit A analogues is described. This method relies on iridium-catalysed stereo- and enantioselective crotylation and chemoselective one-pot oxidative olefination to access common intermediate . Heck, cross metathesis, and Suzuki-Miyaura reactions are illustrated for the generation of methyl ester unit A analogues .
描述了一种灵活多变的隐藻素单元 A 类似物的合成方法。该方法依赖于铱催化的立体和对映选择性巴豆化和化学选择性一锅氧化烯化来获得常见的中间体。Heck、交叉复分解和 Suzuki-Miyaura 反应被说明用于生成甲酯单元 A 类似物。
Insulin analogues with a glucose-regulated conformational switch
申请人:CASE WESTERN RESERVE UNIVERSITY
公开号:US10584156B2
公开(公告)日:2020-03-10
A two-chain insulin analogue contains an A chain modified by (i) a monomeric glucose-binding element at or near its N terminus and (ii) a B chain modified by at or near its C terminus by an element that reversibly binds to the monomeric glucose-binding element such that this linkage is displaceable by glucose. The monomeric glucose-binding element may be phenylboronic acid derivative (optionally halogenated). The B chain may be modified by a diol-containing element derived from a monosaccharide, disaccharide or oligosaccharide, a non-saccharide diol-containing moiety or a α-hydroxycarboxylate-containing moiety. The analogue can be manufactured by trypsin-mediated semi-synthesis. Formulations can be at strengths U-10 to U-1000 in soluble solutions at pH 7.0-8.0 with or without zinc ions at a molar ratio of 0.0-3.0 ions per insulin analogue monomer. A patient with diabetes mellitus may be treated with subcutaneous, intraperitoneal, or oral administration of a physiologically effective amount of the insulin analogue.
双链胰岛素类似物的 A 链(i)在其 N 末端或附近被单体葡萄糖结合元件修饰,(ii)B 链在其 C 末端或附近被可逆地与单体葡萄糖结合元件结合的元件修饰,这种连接可被葡萄糖置换。单体葡萄糖结合元件可以是苯硼酸衍生物(可选择卤代)。B 链可由源自单糖、二糖或寡糖的含二醇元素、非糖类的含二醇分子或含α-羟基羧酸分子修饰。类似物可通过胰蛋白酶介导的半合成法制造。制剂在 pH 值为 7.0-8.0 的可溶液中的浓度为 U-10 至 U-1000,可添加或不添加锌离子,每种胰岛素类似物单体的摩尔比为 0.0-3.0 个离子。糖尿病患者可通过皮下注射、腹腔注射或口服生理有效量的胰岛素类似物进行治疗。
Toward the Total Synthesis of Spirastrellolide A. Part 1: Strategic Considerations and Preparation of the Southern Domain
作者:Alois Fürstner、Michaël D. B. Fenster、Bernhard Fasching、Cédrickx Godbout、Karin Radkowski