Synthetic Applications of Carbene and Nitrene C H Insertion

C H functionalization has developed into a powerful strategy for organic synthesis. The use of organometallic approaches has played a central role in these advances. The metal-catalyzed activation of C H bonds has become a very effective transformation, especially when combined with the use of directing groups to ensure that specific C H bonds are selectively functionalized. An alternative transition metal-induced approach is to use a group transfer reaction, in which a metal bound carbene ( 1 ) or nitrene ( 2 ) is inserted into the C H bond ( Scheme 1 ). The metal carbene and metal nitrene C H insertions are catalytic processes and, in many instances, can be highly regio-, diastereo-, and enantioselective by utilizing appropriately designed chiral catalysts. This chapter gives an overview of the recent advances in the metal carbene and nitrene chemistry with an emphasis on enantioselectice C H functionalization reactions.