Synfacts 2007(10): 1007-1007  
DOI: 10.1055/s-2007-968950
Synthesis of Natural Products and Potential Drugs
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Ratanhine

Contributor(s):Philip Kocienski, Stewart Eccles
E. P. Gillis, M. D. Burke*
University of Illinois at Urbana-Champaign, USA
A Simple and Modular Strategy for Small Molecule Synthesis: Iterative Suzuki-Miyaura Coupling of B-Protected Haloboronic Acid Building Blocks
J. Am. Chem. Soc.  2007,  129:  6716-6717  
Further Information

Publication History

Publication Date:
07 November 2007 (online)


Significance

Haloboronic acids protected with trivalent N-methyliminodiacetic acid ligands (e.g. A) undergo iterative Suzuki-Miyaura couplings because the protecting group induces boron pyramidalization that inhibits cross-coupling. Six examples are given along with an application to the synthesis of ratanhine.

Comment

The coupling reaction of boronic acid B with protected boronic ester A proceeded in very high yield and selectivity with the boronic acid reacting preferentially over the boronic ester. Boronic ester D was easily deprotected under mild conditions to give boronic acid E ready for the next coupling step.