Recent Developments Using Amine Initiators

As a further extension, the Kim group very recently developed the aerobic oxidation and [l,5]-hydride transfer/cyclization sequence starting from readily available ortho tertiary amine substituted cinnamyl alcohols 24 (Scheme 4.12). The tetrapropylammonium perruthenate (TPAP) was identified as the competent catalyst for the initial aerobic oxidation of the allylic alcohols. The synthetically useful tetrahydroquinoline derivatives 25 were prepared in moderate yields and high level of enantioselectivity. 

Initially, Pd-catalyzed deprotections were carried out under reductive conditions. The earliest examples of Pd-mediated allyl group deprotection employed formic acid, usually in conjunction with an amine base, at elevated temperature as a hydride source (Scheme 2). Later development of tri- -butyltin hydride as a hydride source has greatly facilitated the reductive deprotection of a wide variety of aUyl-based protecting groups, reacting almost instantaneously at ambient temperature. " Additional hydride sources for allyl group deprotection include phenyltrihydrosilane and several different borohydrides (Scheme Most recently, Guibe and Albericio have used amine-... 

The author expected that a reaction with a chiral ligand which coordinates to a copper atom could produce optically active 2-(aminomethyl)indoles. Knochel recently developed a novel asymmetric synthesis of chiral propargylamines with excellent ee values through a copper-catalyzed asymmetric Mannich-type reaction of alkynes with an aldehyde and a secondary amine using QUINAP as a chiral ligand (up to 98% ee) [1-3]. Carreira reported the similar synthesis of propargylic amine in up to 99% ee with PINAP [4, 5]. The author initially examined the... 

More recently a solvent-free process has been developed for alkanolamide production, which is preferentially carried out at a temperature slightly above the melting point of the alkanolamide product (e.g. at 90 °C for alkanolamides from lauric acid) [14]. Formation of an ion pair salt at equimolar concentrations of ethanolamine and fatty acid results in extremely high viscosity of the medium, even at very high temperatures. This problem could be overcome by using only half of the amine initially the excess of... 

A diverse group of secondary and tertiary amines are readily synthesized from the reaction of primary and secondary amines with allylic carbonates in the presence of preformed iridium metalacycles, but the direct synthesis of primary amines via iridium-catalyzed allylic amination requires the use of ammonia as a nucleophile. The asymmetric allylation of ammonia had not been reported until very recently, and it is not a common reagent in other metal-catalyzed reactions. Nonetheless, Hartwig and coworkers developed the reactions of ammonia with allylic carbonates in the presence of la generated in situ [89]. Reactions conducted in the initial work led exclusively to the products from diallylation (Scheme 16). Further advances in... 

More recent efforts have focused on developments that create true hybrids. For example, blocked isocyanate prepolymers have been mixed with epoxy resins and cured with amines [68-70]. These blocked prepolymers will react initially with the amines to form amine-terminated prepolymers that cross-link the epoxy resin. Several blocked isocyanates are commercially available. The DESMOCAP (Bayer) llA and 12A products are isocyanates (believed to be blocked with nonylphenol) used as flexibilizing agents for epoxy resins. ANCAREZ (trademark. Pacific Anchor, Inc.) 2150 is a blocked isocyanate epoxy blend used as an adhesion promoter for vinyl plastisols. A one-package, heat-cured hybrid adhesive was reported consisting of isophorone diisocyanate, epoxy resin, and a dispersed solid curative based on the salt of ethylenediamine and bisphenol A [71]. Urethane amines are offered commercially that can be used with epoxy resins to develop hybrid adhesive systems [72]. 

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