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Ian R Baxendale

Publications and source records attributed to Ian R Baxendale.

11 recordsLinked to original sources
PubMed2006

Fully automated continuous flow synthesis of 4,5-disubstituted oxazoles.

[Structure: see text] A multipurpose mesofluidic flow reactor capable of producing gram quantities of material has been developed as an automated synthesis platform for the rapid on-demand synthesis of key building blocks and small exploratory libraries. The reactor is configured to provide the maximum flexibility for screening of reaction parameters that incorporate on-chip mixing and columns of solid supported reagents to expedite the chemical syntheses.

Journal Article↗
PubMed2006

Microwave-assisted Suzuki coupling reactions with an encapsulated palladium catalyst for batch and continuous-flow transformations.

This article describes the design, optimisation and development of a Suzuki cross-coupling protocol mediated by an efficient palladium-encapsulated catalyst (Pd EnCat) under microwave irradiation. The methodology has been used in both batch mode for classical library preparation and in continuous-flow applications furnishing multigram quantities of material. Described is a method that uses direct focused microwave heating whilst applying an external cooling source. This enables a lower than normal bulk temperature to be maintained throughout the reaction period leading to significant improvements in the overall yield and purity of the reaction products. Additional aspects of this novel heating protocol are discussed in relation to the prolonged lifetime and enhanced reactivity of the immobilised catalyst system.

Catalysis↗
PubMed2006

A flow process for the multi-step synthesis of the alkaloid natural product oxomaritidine: a new paradigm for molecular assembly.

A flow process for the multi-step synthesis of the alkaloid natural product (+/-)-oxomaritidine is described, mediated through the use of microfluidic pumping systems that progress material through various packed columns containing immobilized reagents, catalysts, scavengers or catch and release agents; our route involves the combination of seven separate synthetic steps linked into one continuous sequence utilizing flow chemistry.

Amaryllidaceae Alkaloids↗
PubMed2005

A phase-switch purification approach for the expedient removal of tagged reagents and scavengers following their application in organic synthesis.

In this paper we wish to report on a variety of expedient chemical transformations and purifications achieved via a generic "catch and release" methodology, based on a synthetically inert bipyridyl chelating tag that can be selectively captured with a resin-bound copper(II) species. Utilising this approach we are able to derive many of the same benefits associated with both solid phase synthesis and supported reagent methods.

2,2'-Dipyridyl↗
PubMed2004

Multi-step application of immobilized reagents and scavengers: a total synthesis of epothilone C.

The total synthesis of the cytotoxic antitumour natural product epothilone C has provided a stage for the exploitation and further development of immobilized reagent methods. A stereoselective convergent synthetic strategy was applied, incorporating polymer-supported reagents, catalysts, scavengers and catch-and-release techniques to avoid frequent aqueous work-up and chromatographic purification.

Antineoplastic Agents↗
PubMed2003

Microwave assisted Leimgruber-Batcho reaction for the preparation of indoles, azaindoles and pyrroylquinolines.

The development of enhanced conditions for Lewis acid catalysed Leimgruber-Batcho indole synthesis using microwave acceleration is described. This approach has permitted the preparation of a variety of heteroaromatic enamine intermediates in good yield and high purities. Subsequent catalytic hydrogenation reactions, under various conditions including the use of a solid-phase encapsulated catalyst, furnish the corresponding indole derivatives in good yields.

Journal Article↗
PubMed2002

Organic synthesis in a changing world.

This article is based on a lecture presented to the Chemical Society of Japan at Wasada University on March 27, 2002, by Professor Steven V. Ley. The lecture, "Organic Synthesis in a Changing World," was a comprehensive account of the ongoing research efforts of professor Ley's group in the development and application of solid-supported reagents and scavengers for use in organic synthesis.

Chemistry, Organic↗
PubMed2002

Solid-supported reagents for multi-step organic synthesis: preparation and application.

Since the early days of combinatorial chemistry solid-phase organic synthesis has been the method of choice for the production of large libraries. Solution-phase synthesis is again gaining importance especially for the synthesis of parallel arrays of smaller, focussed libraries containing single compounds with high degrees of purity. In the field of solution-phase library generation, the use of solid-supported reagents, catalysts and scavengers is emerging as a leading strategy, combining the advantages of both solid-phase organic synthesis (e.g. allowing the employment of an excess of reagent without the need for additional purification steps) and solution-phase chemistry (e.g. the ease of monitoring the progress of the reactions by applying LC-MS, TLC or standard NMR techniques). An account of some of the most recent advances in this area of research will be presented.

Combinatorial Chemistry Techniques↗
PubMed2002

New tools and concepts for modern organic synthesis.

The increasing need to efficiently assemble small molecules as potential modulators of therapeutic targets that are emerging from genomics and proteomics is driving the development of novel technologies for small-molecule synthesis. Here, we describe some of the general applications and approaches to synthesis using one such technology--solid-supported reagents--that has been shown to significantly improve productivity in the generation of combinatorial libraries and complex target molecules.

Organic Chemicals↗
PubMedDate not supplied

Formation of 4-aminopyrimidines via the trimerization of nitriles using focused microwave heating.

A series of substituted aliphatic nitriles have been trimerized to their corresponding pyrimidine structures under solvent-free conditions in the presence of catalytic quantities of potassium tert-butoxide using a focused microwave reactor. Multigram quantities of the corresponding 4-aminopyrimidines have been prepared in high yields and purity following a simple and scaleable protocol.

Butanols↗