Vladimir Savic

Ronald Grigg; Vladimir Savic

Abstract Heating 3- or 4-acetyl pyridine with alkenes in toluene in the presence of 5–10mol% of RuH 2 CO(PPh 3 ) 3 afforded the mono- or a mixture of mono- and di-alkylated products in good yield. Alkylation of acctylindole derivatives was also achieved with similar efficiency.

Ronald Grigg; Vladimir Savic; Vasuki Tambyrajah

Abstract A simple procedure for the preparation of the phenanthrene type heterocycles is described, based on Rh(I) catalysed formation of benzene rings via a [2+2+2]-cycloaddition reaction followed by Pd(0) catalysed intramolecular arylation of the newly formed aromatic functionality.

Ronald Grigg; Vladimir Savic

Abstract Pd(0) catalysed termolecular queuing processes involving oxidative addition to aryl or vinyl halides followed by cyclisation onto a proximate alkyne, allene (1atm) insertion, and capture of the resulting π-allylpalladium(II) species by secondary amines affords 5–8 membered benzoannelated heterocyclic dienes or electrocyclisation products respectively in good yield.

Ronald Grigg; Rukhsana Rasul; Vladimir Savic

Abstract Palladium catalysed regio- and, where appropriate, stereo-specific triscyclisation-anion capture processes are described involving vinyl- and allenyl-starter species, alkene/alkyne relay and terminating species and anion capture by allene/nucleophile (PhSO 2 Na or s-amine) or 2-thienyl tributylstannane.

Ronald Grigg; Vladimir Savic; Mark Thornton-Pett

Abstract The intramolecular cycloaddition reactions of non-stabilised azomethine ylides generated by condensation of 4-(3-propanalyl)-5-methylene-2(5H)furanone and cyclic amino acids were investigated. The reactions proceeded via highly stereoselective formation of anti- dipoles followed by cycloaddition reactions on either the α,β- or γ,δ- double bond to produce polycyclic cycloadducts in good yield. Both double bonds of the lactone moiety proved to be efficient dipolarophiles.

Ronald Grigg; Peter D. Kennewell; Vladimir Savic

Abstract Pd(O) Catalysed cross-coupling of butenolide-3-triflates to 9-alkyl-9-borobicyclo[3.3.1]nonanes occurs in moderate to good yield and tolerates a range of functionality. Application of this methodology combined with addition of diethylzinc to a butenolide aldehyde in the presence of an ephedrine derivative leads to a 3-step synthesis of (−)-isoseiridine with 88%e.e. in good yield.

Ronald Grigg; Peter D. Kennewell; Vladimir Savic; Visuvanathar Sridharan

Abstract Azomethine ylides generated by the decarboxylation of imines of a- amino acids and 2,2′- dipyridyl ketone undergo 1,5-electrocyclisation and subsequent aromatisation to generate 1,3- disubstituted-2-azaindolizines. Azomethine ylides generated from 1,2,3,4- tetrahydroisoquinoline and diarylidene acetone undergo 1,5-electrocyclisation and subsequent prototropic rearrangement. to give pyrrolo-5,6-dihydroisoquinolines.

Sean P. Bew; David L. Hughes; Vladimir Savic; Katy M. Soapi; Martin A. Wilson

We report for the first time that after O-acylation the conjugate addition products of (S)-N-(α-methylbenzyl)hydroxylamine undergo an efficient diastereoselective 3-exo-tet ring-closure reaction affording 2- and 2,3-disubstituted-N-alkylaziridines in good to excellent yields.

Ronald Grigg; Vladimir Savic

Cyclisation of chloroformates onto proximate alkyne functionality in the presence of a Pd(0) catalyst followed by anion capture affords α-methylene-γ-butyrolactone derivatives in moderate to good yields.

Ronald Grigg; Vladimir Savic

Substituted pyrroles are formed in moderate to good yields by the Pd-catalysed cyclisation of enamines containing β-vinyl bromide functionalities.