2-Pyridylsilyl Group: A Useful Multifunctional Group in Organic Synthesis

The utility of the 2-pyridylsilyl group as a multifunctional group in organic synthesis is described. The use of the 2-pyridylsilyl group as a removable directing group is a powerful synthetic strategy that circumvents the specificity-generality dilemma in metal-mediated organic synthesis. In addition, the utility of the 2-pyridylsilyl group as a phase tag for strategic separation and as a removable hydrophilic group for aqueous reactions is also described. 1 Introduction 2 Transformations of the 2-Pyridylsilyl Group to Other Groups 3 The 2-Pyridylsilyl Group as a Removable Directing Group for Organometallic Reactions 3.1 Deprotonative Lithiation of Methyl(2-pyridyl)silanes 3.2 Peterson Olefination Using [Bis(2-pyridyl­silyl)methyl]lithium 3.3 Carbomagnesation Across Alkenyl(2-pyridyl)silanes 3.4 Carbomagnesation Across Alkynyl(2-pyridyl)silanes 3.5 Mizoroki-Heck Reaction of Alkenyl(2-pyridyl)silanes 3.6 Hiyama Coupling of Alkenyl(2-pyridyl)silanes 3.7 Homocoupling of Alkenyl(2-pyridyl)silanes 3.8 Programmable Synthesis of Arylethene-Based Extended (pi)-Systems 3.9 Pauson-Khand Reaction Using Alkenyl(2-pyridyl)silanes 3.10 Stille Coupling of Stannylmethyl(2-pyridyl)silanes 3.11 Hiyama Coupling of Benzyl(2-pyridyl)silanes 3.12 Carbonyl Allylation Using Allyl(2-pyridyl)silanes 3.13 Hydrosilylation Using Hydro(2-pyridyl)silanes 3.14 Allylic Alkylation Directed by the 2-Pyridylsilyl Group 4 The 2-Pyridylsilyl Group as a Phase Tag for Solution-Phase Synthesis 5 The 2-Pyridylsilyl Group as a Removable Hydrophilic Group for Aqueous Reactions 5.1 Diels-Alder Reaction 5.2 Photocycloaddition 6 Conclusions and Outlook