Overman rearrangement

The Overman rearrangement is a chemical reaction that can be described as a Claisen rearrangement of allylic alcohols to give allylic trichloroacetamides through an imidate intermediate.{{cite journal

| title = A general method for the synthesis of amines by the rearrangement of allylic trichloroacetimidates. 1,3 Transposition of alcohol and amine functions

| author = Larry E. Overman

| pages = 2901–2910

| doi = 10.1021/ja00426a038

| journal = J. Am. Chem. Soc.

| issue = 10

| year = 1976

| volume = 98}}{{cite journal

| last = Overman

| first = L. E.

| title = Allylic and propargylic imidic esters in organic synthesis

| journal = Accounts of Chemical Research

| year = 1980

| volume = 13

| issue = 7

| pages = 218–224

| doi = 10.1021/ar50151a005}}Organic Syntheses, Coll. Vol. 6, p.507; Vol. 58, p.4 ([http://www.orgsyn.org/orgsyn/prep.asp?prep=cv6p0507 Article] {{Webarchive|url=https://web.archive.org/web/20110514024842/http://www.orgsyn.org/orgsyn/prep.asp?prep=cv6p0507 |date=2011-05-14 }}) The Overman rearrangement was discovered in 1974 by Larry Overman.{{cite journal

| last = Overman

| first = L. E.

| title = Thermal and mercuric ion catalyzed [3,3]-sigmatropic rearrangement of allylic trichloroacetimidates. 1,3 Transposition of alcohol and amine functions

| journal = Journal of the American Chemical Society

| year = 1974

| volume = 96

| issue = 2

| pages = 597–599

| doi = 10.1021/ja00809a054}}

File:Overman Rearrangement scheme.svg

The [3,3]-sigmatropic rearrangement is diastereoselective and requires heating or the use of Hg(II) or Pd(II) salts as catalysts.{{cite journal | last1 = Overman | first1 = L. E. | last2 = Carpenter | first2 = N. E. | year = 2005 | title = The Allylic Trihaloacetimidate Rearrangement| journal = Org. React. | volume = 66 | page = 1 | doi = 10.1002/0471264180.or066.01 | isbn = 0471264180 }} The resulting allylamine structures can be transformed into many chemically and biologically important natural and un-natural amino acids (like (1-adamantyl)glycine).{{cite journal | last=Chen | first=Y. K. |author2=Lurain, A. E. |author3=Walsh, P. J. | title=A General, Highly Enantioselective Method for the Synthesis of D and L α-Amino Acids and Allylic Amines | journal=Journal of the American Chemical Society | year=2002 | volume=124 | issue=41 | pages=12225–12231 | doi =10.1021/ja027271p | pmid=12371863}}

The Overman rearrangement may also be used for asymmetric synthesis.Anderson, C. E.; Overman, L. E. J. Am. Chem. Soc. 2003, 125, 12412–12413. ({{doi|10.1021/ja037086r}})Asymmetric Overman Rearrangement Organic Syntheses, Vol. 82, p.134 (2005). ([http://www.orgsyn.org/orgsyn/prep.asp?prep=v82p0134 Article] {{Webarchive|url=https://web.archive.org/web/20110514025034/http://www.orgsyn.org/orgsyn/prep.asp?prep=v82p0134 |date=2011-05-14 }})