Prev. Article Next Article Table of Contents

Letter

Magnesiated Unsaturated Silylated Cyanohydrins as Synthetic Equivalents of Aromatic and Heterocyclic Grignard Reagents Bearing a Ketone or an Aldehyde

Supporting Info

Ching-Yuan Liu, Hongjun Ren, and Paul Knochel*

Department Chemie und Biochemie, Ludwig-Maximilians-Universitt, Butenandtstrasse 5-13, 81377 Mnchen, Germany

Org. Lett., 2006, 8 (4), pp 617–619

DOI: 10.1021/ol052792d

Publication Date (Web): January 26, 2006

In papers with more than one author, the asterisk indicates the name of the author to whom inquiries about the paper should be addressed.

, paul.knochel@cup.uni-muenchen.de

Abstract

The preparation of iodo-substituted aryl, heteroaryl, or cycloalkenyl ketones as silylated cyanohydrins allows the smooth performance of an I/Mg-exchange using i-PrMgCl·LiCl. A facile deprotection of the resulting functionalized products obtained by a reaction with electrophiles (acid chlorides, allylic bromide, benzylidene-p-toluenesulfonamide, and 3-iodocyclohexenone) produces polyfunctional ketones in good overall yields. This sequence can be extended to aromatic iodoaldehydes. In these cases, the deprotection of the silylated cyanohydrin functionality is best performed with aqueous CuSO₄ under basic conditions.

View: Full Text HTML | Hi-Res PDF

Tools

SciFinder Links

History

Published In Issue February 16, 2006
Received November 18, 2005

Recommend & Share

Related Content

Stereoselective Preparation of Functionalized Acyclic Alkenylmagnesium Reagents Using i-PrMgCl·LiClOrganic Letters
- Stereoselective Preparation of Functionalized Acyclic Alkenylmagnesium Reagents Using i-PrMgCl·LiCl
  Hongjun Ren, Arkady Krasovskiy, and Paul Knochel
  Organic Letters 2004 6 (23), pp 4215–4217
  Abstract: Acyclic functionalized alkenyl iodides are converted with high stereoselectivity to the corresponding functionalized alkenylmagnesium derivatives by the reaction with i-PrMgCl·LiCl between −40 and −20 °C. Functional groups such as a nitrile, chloride, ...
  Abstract | Full Text HTML | Hi-Res PDF
Grignard Reagents: Alkoxide-Directed Iodine−Magnesium Exchange at sp³ CentersOrganic Letters
- Grignard Reagents: Alkoxide-Directed Iodine−Magnesium Exchange at sp³ Centers
  Fraser F. Fleming, Subrahmanyam Gudipati, Viet Anh Vu, Robert J. Mycka, and Paul Knochel
  Organic Letters 2007 9 (22), pp 4507–4509
  Abstract: Sequential addition of i-PrMgCl and BuLi to sp³ hybridized iodoalcohols triggers a facile iodine−metal exchange. Intercepting the resulting cyclic Grignard reagents with a slight excess of an electrophile leads to a diverse range of substituted alcohols. ...
  Abstract | Full Text HTML | Hi-Res PDF
Highly Functionalized Benzene Syntheses by Directed Mono or Multiple Magnesiations with TMPMgCl·LiClOrganic Letters
- Highly Functionalized Benzene Syntheses by Directed Mono or Multiple Magnesiations with TMPMgCl·LiCl
  Wenwei Lin, Oliver Baron, and Paul Knochel
  Organic Letters 2006 8 (24), pp 5673–5676
  Abstract: The direct magnesiation of highly functionalized aromatics bearing an ester, a nitrile, or a ketone can be readily performed by using an OBoc as a directing group and TMPMgCl·LiCl as a base. It allows, for example, the preparation of a meta-magnesiated ...
  Abstract | Full Text HTML | Hi-Res PDF

Letter

Magnesiated Unsaturated Silylated Cyanohydrins as Synthetic Equivalents of Aromatic and Heterocyclic Grignard Reagents Bearing a Ketone or an Aldehyde