Push–pull carbenes: methoxytrifluoromethylcarbene

Abstract

Despite the possibility of 'push-pull' carbene stabilization by su bstituents of opposing electronic properties, absolute rate studies show methoxytrifluoromethylcarbene to be highly reactive and electronically indiscriminant in its reactions with alkenes.

Effects of CF3 groups and charged substituents on singlet carbene stabilities–a density functional theory study

“…Likewise, other strongly electron‐withdrawing groups such as CF 3 should show similar rehybridization effects. Others have noted the possible influence of the CF 3 inductive effect on singlet carbene stability, including in combination with other stabilizing groups …”

“…Others have noted the possible influence of the CF 3 inductive effect on singlet carbene stability, [19,21] including in combination with other stabilizing groups. [36,37] Indeed, there are various clues that an inductively induced rehybridization effect operates in singlet CF 3 carbenes. For example, although the steric bulk of CF 3 should be greater than CH 3 , [28] calculations predict that the bond angle in the CF 3 carbene 5 (103.0 ) is somewhat smaller than that in the singlet state of CH 3 carbene 10 (105.9 ).…”

The Hydrido‐Transition Metal Cluster Complexes

“…An interesting series of catenated hydrido-metal complexes H2 [Os (CO),]., n = 1, 2, 3, and 4, is obtained in the high-pressure carbonylation of Os04 in the presence of hydrogen (194,196,197). For n = 3 and 4, these contrast both in stoichiometry and structure the triangular [H20s3(CO)1 or tetrahedral [H40s4(C0)1 2 ] complexes obtained in the direct reaction of H2 with O S~( C O )~ mentioned above.…”

Visible-Light-Induced Organocatalyzed [2+1] Cyclization of Alkynes and (Trifluoroacetyl)silanes

“…In 1991, Moss and co-workers found that methoxyltrifluoromethylcarbene could react with different alkenes without significant discrimination of their electronic properties to form cyclopropanation products. 47 Inspired by these seminal work in the carbene chemistry, we further envisaged that a trifluoromethyl siloxyl carbene formed from a trifluoroacetylsilane may be a amphiphilic donoracceptor carbene, and it would undergo [2+1] cyclization reaction with various alkynes (Figure 1c).…”