Annual Reports, Section Baims to provide an overview of the most important advances and achievements in organic chemistry and related fields, described in the literature of a calendar year.The chapters on synthetic aspects of organic chemistry this year include the regular reports on recent advances in synthetic methodology together with coverage of other important areas of research in organic synthesis. New chapters this year include oxidation and reduction methods and marine natural products; new authors include Gareth Rowlands, Alan Armstrong, Paul Clarke, and Bob Hill.The core chapters on synthetic methodology cover a very wide range of reaction type. Ian Fairlamb continues his thorough coverage of organometallic chemistry. Matthew Fletcher again writes about heteroatom methods. Gareth Rowlands succeeds Clive Penkett in discussing free radical methodology, and Paul Clarke takes over from Alan Spivey in reporting on protecting groups. Advances in the field of oxidation and reduction methodology are discussed for the first time by Alan Armstrong.Rob Stockman continues his contribution on heterocyclic chemistry, and Steve Allin’s commentary on highlights of natural product synthesis also appears in Annual Reports for the second time in this volume.The interface of the biological sciences with chemistry continues to provide new opportunities for research. In this field, Ben Davis writes again about enzyme methods, and Harri Lönnberg describes advances in the chemistry of natural polymers. The field of supramolecular chemistry continues to evolve rapidly; Phil Gale addresses some of the most interesting developments in his second year of contributing to Annual Reports.The chapters on physical aspects of organic chemistry contain a blend of authors continuing from last year and new contributors. There are three core chapters on organic reaction mechanisms. James Tanko has replaced Mark Workentin in preparing the chapter on “Radical and radical ion reactions”, and Kevin Dalby and Kathleen Morgan have continued their coverage of “Polar reactions” and “Pericyclic reactions”, respectively.Brian Yates has again contributed a chapter on “Computational organic chemistry” and Mary Boyd has continued to cover “Organic photochemistry”. Paul Wenthold has taken over from Richard O’Hair in covering “Organic gas-phase ion chemistry” and Nicholas Williams has replaced Bruce Armitage in contributing a chapter on “Bioinspired organic chemistry”.The Scientific Editors wish to express their appreciation to the work of this year’s reporters, without whom there would be no volume 99.