Samarium Triiodide

Biographical Sketches

Yuanmin Zhang was born in Gansu, P. R. of China and received her B.Sc. degree (2009) in Chemistry from Tianshui Normal University. She is currently pursuing her M.Sc. degree under the supervision of associate professor Dr. Zhengyin Du at the College of Chemistry and Chemical Engineering, Northwest Normal University. Her research interests focus on the development of new synthetic methodologies for green chemistry.

Introduction

<P>Samarium triiodide (SmI₃) is a yellow powder with a melting point of 820 ˚C, unstable towards air and moisture. It is commercially available and has been widely used in organic reactions, such as elimination, conjugate addition, carbonyl reduction, intramolecular cyclization and nucleophilic substitution reactions. It can also be regarded as an efficient metal catalyst and a Lewis acid catalyst to accelerate reactions and to improve yields for organic transformations. Herein, the applications of SmI₃ in recent years are listed and reviewed.</P>

Abstracts

<TD VALIGN="TOP"> (A) A novel and highly efficient method for the conjugate addition of indoles with electron-deficient olefins catalyzed by SmI₃ afforded a series of new 3-substituted indole derivatives. [¹] [²] This reaction is highly regioselective and can be accelerated by microwave irradiation with silica gel as catalyst support. [³] </TD><TD VALIGN="TOP">

</TD><TD VALIGN="TOP"> (B) The Michael reaction of β-diketones with α,β-unsaturated esters catalyzed by samarium triiodide was achieved in THF under reflux to give the corresponding δ-carbonyl esters in good yields. [4] </TD><TD VALIGN="TOP">

</TD><TD VALIGN="TOP"> (C) The nucleophilic substitution reaction between N-(1-benzotriazol-1-ylalkyl)amides and 1,3-dicarbonyl compounds promoted by samarium triiodide was reported. This provides a useful method for the preparation of Mannich-type products with good yields and high ­diastereoselectivities. [5] </TD><TD VALIGN="TOP">

</TD><TD VALIGN="TOP"> (D) Catalyzed by SmI₃, a series of arylamines reacted with dihydropyran to give pyrano[3,2-c]quinoline derivatives in moderate to good yields with high trans diastereoselectivity. [6] </TD><TD VALIGN="TOP">

</TD><TD VALIGN="TOP"> (E) A simple methodology to prepare (E)-α-hydroxy-β,γ-unsaturated amides from α,β-epoxyamides, by using catalytic samarium triiodide, has been developed. This elimination reaction proceeds with total or high diastereoselectity and regioselectivity. [7] </TD><TD VALIGN="TOP">

</TD><TD VALIGN="TOP"> (F) 1,1-Diacetates undergo deprotection and condensation reaction with cycloalkanones in the presence of catalytic samarium triiodide to afford α,α′-bis(substituted benzylidene)cycloalkanones in good yields. [8] </TD><TD VALIGN="TOP">

</TD><TD VALIGN="TOP"> (G) A new and facile method to prepare (Z)-allylic iodides 2 from the acetates of Baylis-Hillman adducts 1 mediated by samarium triiodide was developed in ionic liquid [bmim]BF₄ with excellent yields and good stereoselectivity. [9] </TD><TD VALIGN="TOP">

</TD><TD VALIGN="TOP"> (H) A novel, one-pot three-component reaction of aldehydes, α-halo ketones and (phenylsulfonyl)acetonitrile was achieved in good yields in the presence of samarium triiodide. [¹0] </TD><TD VALIGN="TOP">

</TD><TD VALIGN="TOP"> (I) SmI₃-promoted β-elimination reactions of α-chloro-β-hydroxy ketones offer a highly efficient way to synthesize α,β-unsaturated ketones in good yields and E-diastereoselectivity. [¹¹] </TD><TD VALIGN="TOP">

</TD><TD VALIGN="TOP"> (J) Samarium triiodide can also be used for the catalytic reduction of the saturated steroidal ketone into the corresponding secondary alcohol. [¹²] </TD><TD VALIGN="TOP">

</TD>

References

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