Synthesis 1979; 1979(8): 561-576
DOI: 10.1055/s-1979-28761
review
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Esterification and Alkylation Reactions Employing Isoureas

Lon J. Mathias*
  • *Department of Chemistry, Auburn University, Auburn, Alabama 36830, U.S.A.
Further Information

Publication History

Publication Date:
14 May 2002 (online)

The synthetic applications of isoureas as alkylating agents are evaluated and reviewed. Esterifications employing isoureas were reported many years ago, but extended applications were inhibited by lack of isourea availability. A high-yield, mild synthesis of a major group of isoureas first appeared in 1955. This spurred numerous exploratory efforts which have extended alkylation reactions to a variety of carbon- and heteroatom-containing groups. These procedures are discussed in detail with respect to generality and selectivity. A discussion of the probable mechanism helps explain the observed selectivity and indicates potential developments of isoureas as general alkylating agents. A brief survey of the large number of available isoureas supports predictions as to their importance as reagents for analysis and organic synthesis. 1 . Introduction 2. Carboxylic Ester Formation 3. Phosphate Ester and Phenyl Ether Synthesis 4. Sulfur Alkylation 5. Nitrogen Alkylations 6. Active Carbon Alkylations 7. Isourea Rearrangements/Internal Alkylation 8.1 Mechanism of Alkylation 8.2 Heteroatom Selectivity in Alkylations 9. lsourea Availability