1,4-Diazaspiro[2.2]pentanes as a flexible platform for the synthesis of diamine-bearing stereotriads

J Org Chem. 2012 Mar 2;77(5):2446-55. doi: 10.1021/jo3000282. Epub 2012 Feb 14.

Abstract

Nitrogen-containing stereotriads occur in a number of biologically active compounds, but general and flexible methods to access these compounds are limited mainly to the manipulation of chiral olefins. An alternative approach is to employ a highly chemo-, regio-, and stereocontrolled allene oxidation that can install a new carbon-heteroatom bond at each of the three original allene carbons. In this paper, an intramolecular/intermolecular allene bis-aziridination is described that offers the potential to serve as a key step for the construction of stereotriads containing vicinal diaminated motifs. The resultant 1,4-diazaspiro[2.2]pentane (DASP) scaffolds contain two electronically differentiated aziridines that undergo highly regioselective ring openings at C1 with a variety of heteroatom nucleophiles to give chiral N,N-aminals. Alternatively, the same DASP intermediate can be induced to undergo a double ring-opening reaction at both C1 and C3 to yield vicinal diaminated products corresponding to formal ring opening at C3. The chirality of a propargyl alcohol is easily transferred to the DASP with good fidelity, providing a new paradigm for the construction of enantioenriched nitrogen-containing stereotriads.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Diamines / chemical synthesis*
  • Diamines / chemistry
  • Molecular Structure
  • Spiro Compounds / chemistry*
  • Stereoisomerism

Substances

  • 1,4-diazaspiro(2.2)pentane
  • Diamines
  • Spiro Compounds