Reactions with Carbenes and Nitrenes

3-DIBF and related compounds react with carbenes to give adducts of type 133 [84IJC(B)512, 84TL(25)5509]. With phthalimidonitrene (generated in situ from the corresponding A-amino derivative) compound 134 is obtained. 4,7-Dihydro-l,3-diphenylisobenzofuran reacts similarly [72JCS(P1)2728]. 

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The reactions of thiophene with carbenes and nitrenes were discussed in detail in CHEC-II(1996). The preparation of S,N-ylides by an improved method is discussed in Section 3.10.3.3. 

A review on the CH insertion reactions of carbenes and nitrenes with alkanes has appeared developing the current state of the art of this valuable synthetic method. ... 

Reactions with Radicals and Electron-deficient Species Reactions at Surfaces 4.02.1.8.1 Carbenes and nitrenes... 

Reactions of 1,3,4-oxadiazoles at the ring atoms with radicals, carbenes, and nitrenes or with other electron-deficient species are rather uncommon. CHEC(1984) and CHEC-II(1996) have reported very few examples of such reactions concerning oxadiazolinones and oxadiazolinethiones. This situation has not changed. 

In contrast to considerations of 50 years ago, today carbene and nitrene chemistries are integral to synthetic design and applications. Always a unique methodology for the synthesis of cyclopropane and cyclopropene compounds, applications of carbene chemistry have been extended with notable success to insertion reactions, aromatic cycloaddition and substitution, and ylide generation and reactions. And metathesis is in the lexicon of everyone planning the synthesis of an organic compound. Intramolecular reactions now extend to ring sizes well beyond 20, and insertion reactions can be effectively and selectively implemented even for intermolecular processes. 

Reactions with Free Radicals, Carbenes and Nitrenes, and at Surfaces 389... 

The attempted trifluoromethylation of pentamethylcyclopentadienyllithium by reaction with F3 Cl in the presence of A-phenylmaleimide gave rise to the unexpected Diels-Alder adduct (25).37 The authors proposed that the cyclopentadienyl anion captures the iodine of CF3I to give (26) and trifhjoromethyllithium which then produces difluorocarbene (F2C ) which inserts into the C—I bond of (26) to form the difluoroiodomethylated product. The observed regioselectivity of addition of thiazyl chloride (N=S—Cl) to 2,5-diarylftirans provided support for a mechanism involving carbene and nitrene intermediates (27).38... 

In addition to carbenes and nitrenes, organometallic species such as germylenes 107 have been utilized in [2 + 1] cycloadditions and, upon reaction with thioketones, afforded the corresponding thiagermiranes which are very stable and do not decompose even when heated to their melting point438 (equation 124). 

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