Catalytic enantioselective C-H activation by means of metal-carbenoid-induced C-H insertion.

Alan Ford,† Hugues Miel, Aoife Ring,† Catherine N. Slattery,† Anita R. Maguire,*,†,‡ and M. Anthony McKervey* †Department of Chemistry and ‡School of Pharmacy, Analytical and Biological Chemistry Research Facility, Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork, Ireland Almac Discovery Ltd., David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom Almac Sciences Ltd., Almac House, 20 Seagoe Industrial Estate, Craigavon BT63 5QD, United Kingdom

Modern Organic Synthesis with α-Diazocarbonyl Compounds

Heterocycles constitute the largest and the most diverse family of organic compounds Among them, aromatic heterocycles represent structural motifs found in a great number of biologically active natural and synthetic compounds, drugs, and agrochemicals Moreover, aromatic heterocycles are widely used for synthesis of dyes and polymeric materials of high value 1 There are numerous reports on employment of aromatic heterocycles as intermediates in organic synthesis 2

Although, a variety of highly efficient methodologies for synthesis of aromatic heterocycles and their derivatives have been reported in the past, the development of novel methodologies is in cuntinious demand Particlularly, development of new synthetic approaches toward heterocycles, aiming at achieving greater levels of molecular complexity and better functional group compatibilities in a convergent and atom economical fashions from readily accessible starting materials and under mild reaction conditions, is one of a major research endeavor in modern synthetic organic chemistry Transition metal-catalyzed transformations, which often help to meet the above criteria, are among the most attractive synthetic tools

Several excellent reviews dealing with transition metal-catalyzed synthesis of heterocyclic compounds have been published in literature during recent years Many of them highlighted the use of a particular transition metal, such as gold,3 silver,4 palladium,5 copper,6 cobalt,7 ruthenium,8 iron,9 mercury,10 rare-earth metals,11 and others Another array of reviews described the use of a specific kind of transformation, for instance, intramolecular nucleophilic attack of heteroatom at multiple C–C bonds,12 Sonogashira reaction,13 cycloaddition reactions,14 cycloisomerization reactions,15 C–H bond activation processes,16 metathesis reactions,17 etc Reviews devoted to an application of a particular type of starting materials have also been published Thus, for example, applications of isocyanides,18 diazocompounds,19 or azides20 have been discussed In addition, a significant attention was given to transition metal-catalyzed multicomponent syntheses of heterocycles21 Finally, syntheses of heterocycles featuring formation of intermediates, such as nitrenes,22 vinylidenes,23 carbenes, and carbenoids24 have also been reviewed

The main focus of the present review is a transition metal-catalyzed synthesis of aromatic monocyclic heterocycles The organization of the review is rather classical and is based on a heterocycle, categorized in the following order: (a) ring size of heterocycle, (b) number of heteroatoms, (c) type of heterocycle, and (d) a class of transformation involved A brief mechanistic discussion is given to provide information about a possible reaction pathway when necessary The review mostly discusses recent literature, starting from 200425 until the end of 2011, however, some earlier parent transformations are discussed when needed

Transition Metal-Mediated Synthesis of Monocyclic Aromatic Heterocycles

Recent progress in the synthesis of 1,2,3,4,-tetrahydroquinolines

Enantiospecific Synthesis of Heterocycles from α-Amino Acids

A series of acyclic α-carbomethoxy-α-diazoacetanilides with different N-substituents, 5a-k, was prepared and the rhodium(II) acetate catalyzed reactions studied. It was found that the rhodium carhenoid reaction with these compounds occurred only at the N-substituent; when the N-substituent is a propargyl group, rhodium carbenoid addition to the triple bond is favored, resulting, ultimately, in the formation of a bicyclic furan derivative 8. With an N-(tert-butyloxycarbonyl)methyl substituent, interception of the rhodium carhenoid by the ester carbonyl oxygen occurred preferentially to give, eventually, 1,4-oxazine derivatives 9 and 9'

Dirhodium tetraacetate catalyzed carbon-hydrogen insertion reaction in N-substituted .alpha.-carbomethoxy-.alpha.-diazoacetanilides and structural analogs. Substituent and conformational effects

The Still-Wittig Rearrangement in the Preparation of a Synthetically Useful 4C-Hydroxymethyl-hex-2-eno-pyranoside

An unusual epimerization in the oxidation of a 4c-(hydroxymethyl)-2,3,4-trideoxy-2-hexenopyranoside using fetizon's reagent

(1996). AN UNUSUAL EPIMERIZATION IN THE OXIDATION OF A 4C-(HYDROXYMETHYL)-2,3,4-TRIDEOXY-2-HEXENOPYRANOSIDE USING FETIZON'S REAGENT. Organic Preparations and Procedures International: Vol. 28, No. 3, pp. 339-344.

Lin Zhang

Papers

Dirhodium tetraacetate catalyzed carbon-hydrogen insertion reaction in N-substituted .alpha.-carbomethoxy-.alpha.-diazoacetanilides and structural analogs. Substituent and conformational effects

The Still-Wittig Rearrangement in the Preparation of a Synthetically Useful 4C-Hydroxymethyl-hex-2-eno-pyranoside

An unusual epimerization in the oxidation of a 4c-(hydroxymethyl)-2,3,4-trideoxy-2-hexenopyranoside using fetizon's reagent

An Unusual Epimerization in the Oxidation of a 4C-(Hydroxymethyl)-2,3, 4-trideoxy-2-hexenopyranoside Using Fetizon′s Reagent.