In May of 1978, several hundred of the friends, colleagues and former students of Professor Herbert C. Brown gathered on the campus of Purdue University to note his formal retirement, to honor him for his past contributions to chemistry and to wish him continued success in research. It was a time of reunion and recollection, a time for looking back and giving recognition to a lifetime of accomplishment. There was the ceremony of a banquet, presided over with inimitable wit by Professor Derek Davenport, and the dedication of the Herbert C. Brown Archives, with addresses by Dr. Alfred Bader, of Aldrich Chemicals, and Dr. Alan Schriesheim, of Exxon. There was the publi­ cation of a book of the personal reminiscences of students and post­ doctoral colleagues - "Remembering HCB." But it was also a time for looking at the present and into the future with a set of scien­ tific lectures, mainly by former students or associates, who des­ cribed their current or projected research activities. That is what this book is about. The papers, some of which are expanded versions of the lectures, fall into two broad groups - some deal with the interplay of struc­ ture and mechanism, the others deal with the use of organometallics in synthesis. It is, perhaps, no accident that these are the two main areas of H. C. Brown's research interest.