Stereoselective Alkylation of (S)-N-Acyl-4-isopropyl-1,3-thiazolidine-2-thiones Catalyzed by (Me3P)2NiCl2
摘要:
The structurally simple (Me3P)(2)NiCl2 complex catalyzes S(N)1-type alkylations of chiral N-acyl thiazolidinethiones with diarylmethyl methyl ethers and other stable carbenium cations. The former can contain a variety of functional groups and heteroatoms at the alpha-position. The resultant adducts are isolated as single diastereomers in high yields and can be converted into enantiomerically pure derivatives in a straightforward manner.
Synthesis and in-vitro/in-vivo evaluation of orally administered entacapone prodrugs
作者:Jukka Leppänen、Jouko Savolainen、Tapio Nevalainen、Markus Forsberg、Juhani Huuskonen、Hannu Taipale、Jukka Gynther、Pekka T Männistö、Tomi Järvinen
DOI:10.1211/0022357011778025
日期:2010.2.18
acyloxyacyl esters, an acyloxyalkyl ether and an alkyloxycarbonyl ester of entacapone, and we have evaluated them as potential prodrugs to enhance the oral bioavailability of entacapone. All the derivatives fulfilled prodrug criteria and released entacapone in human serum in-vitro. The oral bioavailability of monopivaloyl (1a) and dipivaloyl (1b) esters of entacapone were investigated further in rats
恩他卡朋是儿茶酚-O-甲基转移酶(COMT)的新型抑制剂,可作为左旋多巴疗法的辅助治疗帕金森氏病。但是,口服他卡朋的生物利用度相对较低(29-46%)。在这项研究中,我们制备了更多的恩他卡朋的亲脂性酰基酯和酰氧基酰基酯,酰氧基烷基醚和烷氧基羰基酯,我们将它们评估为增强恩他卡朋口服生物利用度的潜在前药。所有衍生物均符合前药标准,并在人血清中体外释放他卡酮。在大鼠中进一步研究了entacapone的单新戊酰基(1a)和二新戊酰基(1b)酯的口服生物利用度。1b的亲脂性较高(在pH 7.4时,log Papp 4.0),但口服生物利用度较低(F = 0.6%),最可能是由于其低水溶性。在pH 7.4时,entacapone(1a)的单新戊酰基酯的亲脂性(log Papp 0.80)比entacapone(log Papp 0.18)高,同时保持水溶性等于entacapone。但是,与母体药物恩他
Direct <i>anti</i>
Glycolate Aldol Reaction of Protected Chiral <i>N</i>
-Hydroxyacetyl Thiazolidinethiones with Acetals Catalyzed by a Nickel(II) Complex
作者:Juan Manuel Romo、Pedro Romea、Fèlix Urpí
DOI:10.1002/ejoc.201901097
日期:2019.9.30
Tiny amounts of commercially available and easy to handle (Me3P)2NiCl2 trigger the stereoselective aldol addition of chiral N‐2‐pivaloyloxyacetyl thiazolidinethione 7 to acetals to provide the corresponding anti glycolate adducts in a highly efficient manner.
Process for the preparation of 6-oxopenicillanates
申请人:GLAXO S.p.A.
公开号:EP0367606A1
公开(公告)日:1990-05-09
A process is provided for the preparation of compounds of formula (I)
which comprises ozonization of a solution of a diazo compound of formula (II)
at a temperature below 0°C in an organic soylent.
Synthesis of Pyridazine Derivatives via Aza-Diels–Alder Reactions of 1,2,3-Triazine Derivatives and 1-Propynylamines
作者:Takayuki Kodama、Ikuo Sasaki、Hideyuki Sugimura
DOI:10.1021/acs.joc.1c00851
日期:2021.7.2
preparation of pyridazine derivatives via the aza-Diels–Alder reaction of 1,2,3-triazines with 1-propynylamines under neutral conditions. This methodology allowed direct access to a wide range of 6-aryl-pyridazin-3-amines in high yields with good functional group compatibility. Key features of this strategy included a broad substrate scope and simple, metal-free, and neutral reaction conditions.
申请人:State of Oregon acting by and through the State Board of Higher Education on behalf of the Univers
公开号:US20150023643A1
公开(公告)日:2015-01-22
Gradient index optical materials are formed by drop by drop dispensing of nanoparticle/monomer suspensions. Refractive index variations are defined by nanoparticle concentrations that can vary in three dimensions. Droplets of differing compositions can be mixed, and droplets or layers or droplets are partially cross-linked by exposure to ultraviolet radiation prior to dispensing additional droplets. Gradient index optical elements such as lenses, prisms, and waveguides can be formed in flexible polymer layers.