Synthesis of (±)-coerulescine and a formal synthesis of (±)-horsfiline
摘要:
A straightforward synthesis of (+/-)-coerulescine and (+/-)-horsfiline has been established from 3-formyl-3-phenylpyrridine employing 4-hydroxypiperidine as the starting material. There are two remarkable steps for the synthesis of (+/-)-coerulescine and ()-horsfiline. One is the rapid access to produce 3-formyl-3-phenylpyrrolidine by Lewis acid-catalyzed rearrangement of 3,4-dihydroxy-4-phenylpiperidine. The other key step is an intramolecular electrophilic cyclization from 3-benzylcarbamoyl-3-plienylpyrrolidine to the 3,3-spirocyclic 2-oxindole ring skeleton. (c) 2005 Elsevier Ltd. All rights reserved.
Synthesis of (±)-coerulescine and a formal synthesis of (±)-horsfiline
摘要:
A straightforward synthesis of (+/-)-coerulescine and (+/-)-horsfiline has been established from 3-formyl-3-phenylpyrridine employing 4-hydroxypiperidine as the starting material. There are two remarkable steps for the synthesis of (+/-)-coerulescine and ()-horsfiline. One is the rapid access to produce 3-formyl-3-phenylpyrrolidine by Lewis acid-catalyzed rearrangement of 3,4-dihydroxy-4-phenylpiperidine. The other key step is an intramolecular electrophilic cyclization from 3-benzylcarbamoyl-3-plienylpyrrolidine to the 3,3-spirocyclic 2-oxindole ring skeleton. (c) 2005 Elsevier Ltd. All rights reserved.
Highly Enantioselective Organocatalytic Oxidative Kinetic Resolution of Secondary Alcohols Using Chiral Alkoxyamines as Precatalysts: Catalyst Structure, Active Species, and Substrate Scope
The development and characterization of enantioselective organocatalyticoxidative kinetic resolution (OKR) of racemic secondaryalcoholsusing chiral alkoxyamines as precatalysts are described. A number of chiral alkoxyamines have been synthesized, and their structure-enantioselectivity correlation study in OKR has led us to identify a promising precatalyst, namely, 7-benzyl-3-n-butyl-4-oxa-5-azahomoadamantane
Catalytic Friedel‐Crafts Reactions on Saturated Heterocycles and Small Rings for sp
<sup>3</sup>
‐sp
<sup>2</sup>
Coupling of Medicinally Relevant Fragments
作者:Rosemary A. Croft、Maryne A. J. Dubois、Alexander J. Boddy、Camille Denis、Anna Lazaridou、Anne Sophie Voisin‐Chiret、Ronan Bureau、Chulho Choi、James J. Mousseau、James A. Bull
DOI:10.1002/ejoc.201900498
日期:2019.9
A systematic comparison of Lewis acid catalysts [Ca(II), Li(I) and Fe(III)] is presented for catalytic Friedel–Crafts reactions using alcohols on 4‐, 5‐, and 6‐membered oxygen and nitrogen heterocycles and cyclobutanes, forming gem‐diaryl quaternary centers.
The present invention concerns the novel use of aryl substituted heterocycles of formula I, set out below, which antagonize the pharmacological actions of one of ent endogenous neuropeptide tachykinins an the neurokinin 2 (NK2) receptor making them useful whenever such antagonism is desired, such as in the treatment of asthma and related conditions. The invention also provides pharmaceutical compositions containing the aryl substituted heterocycles for use in such treatment. Certain novel aryl substituted heterocycles of formula I and novel intermediates for their manufacture are also provided. ##STR1##
Direct C–H Allylation of <i>N</i>-Acyl/Sulfonyl Tetrahydroisoquinolines and Analogues
作者:Changcun Yan、Yuxiu Liu、Qingmin Wang
DOI:10.1021/acs.orglett.5b03042
日期:2015.11.20
A highly efficient direct C–H allylation reaction at the α position of N-acyl/sulfonyl tetrahydroisoquinolines under mild conditions was developed. The reaction was also suitable for allylation of other protected nitrogen-containing heterocycles. Several interesting transformations of the products into valuable synthetic intermediates are featured with the successful total synthesis of (±)-crispine
A versatile synthesis of 4-aryl tetrahydropyridines via palladium mediated Suzuki cross-coupling with cyclic vinyl boronates
作者:Paul R Eastwood
DOI:10.1016/s0040-4039(00)00447-0
日期:2000.5
A simple preparation of cyclic vinyl boronates derived from the vinyl triflates of N-protected tetrahydropyridines is described. Suzuki coupling of the boronates with aryl bromides, iodides and triflates proceeds in good yield to give 4-aryl tetrahydropyridines.