Total Syntheses of Angelicoin A, Hericenone J, and Hericenol A via Migratory Prenyl- and Geranylation–Aromatization Sequences
摘要:
A five-step synthesis of the natural product angelicoin A using a late stage highly regioselective palladium(0)-catalyzed decarboxylative prenyl migration and aromatization sequence as the key step is reported. The method was extended with geranyl migration in eight-step total syntheses of hericenone J and hericenol A from geraniol.
One-pot tethering of organic molecules through non-symmetric malonate derivatives
摘要:
A new method for one-pot chemoselective beterobifunctional cross-linking of organic molecules is described. The method is based on tert-butyldiphenylsilyl malonate and involves two sequential carbodiimide couplings with two different molecules possessing a hydroxy or an amino functionality with one intermediate one-pot fluoride deprotection. (c) 2005 Elsevier Ltd. All rights reserved.
OXIDATIVE COUPLING OF ARYL BORON REAGENTS WITH SP3-CARBON NUCLEOPHILES, AND AMBIENT DECARBOXYLATIVE ARYLATION OF MALONATE HALF-ESTERS VIA OXIDATIVE CATALYSIS
申请人:The Governors of the University of Alberta
公开号:US20180186721A1
公开(公告)日:2018-07-05
Described herein are methods of oxidative coupling of aryl boron reagents with sp
3
-carbon nucleophiles, and ambient decarboxylative arylation of malonate half-esters via oxidative catalysis.
Self-condensation of activated malonic acid half esters: a model for the decarboxylative Claisen condensation in polyketide biosynthesis
作者:Youngha Ryu、A.Ian Scott
DOI:10.1016/j.tetlet.2003.08.014
日期:2003.9
The reaction of a malonicacid half oxyester with a N-hydroxysuccinimidyl ester-forming reagent resulted in self-condensation to provide the corresponding 1,3-acetonedicarboxylic acid diester. This new method does not require a divalent metal chelator or a coordinating solvent for successful condensation.
Oxidative coupling of aryl boron reagents with SP3-carbon nucleophiles, and ambient decarboxylative arylation of malonate half-esters via oxidative catalysis
申请人:The Governors of the University of Alberta
公开号:US10364208B2
公开(公告)日:2019-07-30
Described herein are methods of oxidative coupling of aryl boron reagents with sp3-carbon nucleophiles, and ambient decarboxylative arylation of malonate half-esters via oxidative catalysis.
Intramolecular Dehydrogenative Coupling of sp<sup>2</sup> C–H and sp<sup>3</sup> C–H Bonds: An Expeditious Route to 2-Oxindoles
作者:Santanu Ghosh、Subhadip De、Badrinath N. Kakde、Subhajit Bhunia、Amit Adhikary、Alakesh Bisai
DOI:10.1021/ol302767w
日期:2012.12.7
An intramolecular-dehydrogenative-coupling (IDC) using "transition-metal-free" oxidation conditions has been achieved to synthesize a variety of 2-oxindoles bearing an all-carbon quaternary stereogenic center at the benzylic position. The methodology involves a one-pot C-alkylation of beta-N-arylamido esters (3, 6) with alkyl halides using potassium tert-butoxide concomitant with a dehydrogenative coupling. A radical-mediated pathway has been tentatively proposed for the oxidative process.
DDQ-mediated Direct Intramolecular-Dehydrogenative-Coupling (IDC): Expeditious Approach to the Tetracyclic Core of Ergot Alkaloids
An efficient route to 2-oxindoles bearing an all-carbon quaternary center at the pseudobenzylic position has been developed via a DDQ-mediated Intramolecular-Dehydrogenative-Coupling (IDC). The methodology involves a one-pot C-alkylation of beta-N-arylamido esters (7) concomitant with dehydrogenative-coupling in the presence of stoichiometric amount of DDQ. A tentative mechanistic route has been proposed for the oxidative coupling. The methodology provides a two-step entry to the ergoline structure of ergot alkaloids.