Addition of Carbon Nucleophiles containing N, S, P, or Bi substituents

An AMI method has been used to investigate nucleophilic addition of malononitrile anion to carbonyl compounds.115 

2-Halo-1,3-dithiane trans-l,3-dioxides (80 X = Cl, Br) act as diastereoselective carbonyl anion equivalents in reactions with aldehydes.117 The scope of the reaction has been explored by varying the temperature, the aldehyde, and the metal used as counterion. Similarly, metal 1,3-dithianides (81 M = Li, Cu1) can be added diastereoselec-tively to chiral aldehydes subsequent hydrolysis yields an a-hydroxyaldehydc.118 

Examples of 1,13- and 1,14-asymmetric inductions are reported in the case of the addition of sulfone carbanions to benzaldehyde.119 

The Wittig and related reactions have been reviewed in the context of natural product synthesis 120 mechanistic studies of the Wittig reaction have also been reviewed with particular reference to asymmetric induction.121 

Transamiular interactions have been examined in the hexacyclo-[6.6.0.02,6.03,13.04 11.05,9]-tetradecane system.122 For example, the 14-iodo-10-one derivative (82) reacts with triphenylphosphine to give the salt (83), via C(10)—C(14) bond formation. In contrast, the 10,14-dione does not react. 

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