Carbonyl compounds heteroatom nucleophile addition

In his original paper,2 Cram disclosed an alternative model that rationalizes the preferred stereochemical course of nucleophilic additions to chiral carbonyl compounds containing an a heteroatom that is capable of forming a complex with the organometallic reagent. This model, known as the Cram cyclic or Cram chelate model, has been extensively studied by Cram9 and by others,410... 

The chemical behavior of heteroatom-substituted vinylcarbene complexes is similar to that of a,(3-unsaturated carbonyl compounds (Figure 2.17) [206]. It is possible to perform Michael additions [217,230], 1,4-addition of cuprates [151], additions of nucleophilic radicals [231], 1,3-dipolar cycloadditions [232,233], inter-[234-241] or intramolecular [220,242] Diels-Alder reactions, as well as Simmons-Smith- [243], sulfur ylide- [244] or diazomethane-mediated [151] cyclopropanati-ons of the vinylcarbene C-C double bond. The treatment of arylcarbene complexes with organolithium reagents ean lead via conjugate addition to substituted 1,4-cyclohexadien-6-ylidene complexes [245]. 

Additions of Heteroatom Nucleophiles to Carbonyl Compounds and Subsequent Reactions—Condensations of Heteroatom Nucleophiles with Carbonyl Compounds... 

Addition of Heteroatom Nucleophiles to Carbonyl Compounds in Combination with Subsequent SN1 Reactions of the Primary Product Acetalizations... 

The addition of one equivalent of a heteroatom nucleophile to carbonyl compounds was described in Section 9.1. However, if two or more equivalents of the heteroatom nucleophile are present, in many cases the initial addition products (formula A in Figure 9.12) react... 

The former chapter Additions of Heteroatom Nucleophiles to Heterocumulenes, Additions of Heteroatom Nucleophiles to Carbonyl Compounds and Follow-up Reactions has been spht into two separate chapters into Chapter 8 Carbonic Acid Derivatives and Heterocumulenes and Their Interconversion , whose systematic organization should represent a particularly valuable learning aid, and into Chapter 9 Additions of Het-eroatom Nucleophiles to Carbonyl Compounds and Follow-up Reactions—Condensations of Heteroatom Nucleophiles with Carbonyl Compounds. ... 

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