Insertion of an Isolable Dialkylstannylene into C–Cl Bonds of Acyl Chlorides Giving Acyl(chloro)stannanes

Abstract

The reactions of isolable dialkylstannylene 1 with 1-adamantanoyl, 2,2-dimethylpropanoyl, benzoyl, and substituted benzoyl chlorides afford the corresponding acyl­(chloro)­stannanes in good yields. Similar reactions with more reactive acetyl and propanoyl chlorides do not give the corresponding insertion products but the corresponding dichlorostannane by the overreaction. The benzoyl­(chloro)­stannane reacts with acetyl chloride to afford the corresponding 1,2-dione and the dichlorostannane quantitatively. Acyl­(chloro)­stannanes obtained were fully characterized by multinuclear NMR spectroscopy, high-resolution mass spectrometry, and by single-crystal X-ray diffraction studies.

Reactions of an Isolable Dialkylgermylene with Acyl Chlorides Forming Acyl(chloro)germanes and Diacylgermanes

“…We have studied herein the reactions of isolable dialkylgermylene 1 (Chart ) with various acyl chlorides in detail. Germylene 1 inserts into the C­(O)–Cl bonds of benzoyl, substituted benzoyl, and 2,2-dimethylpropanoyl chlorides providing exclusively the corresponding acyl­(chloro)­germanes 2 , similarly to the corresponding dialkylsilylene A and dialkylstannylene B . In contrast, 1 reacts with simple alkanoyl chlorides giving rather unusually a significant amount of the corresponding diacylgermanes 3 , in addition to the corresponding acyl­(chloro)­germanes 2 as major products.…”

“…Because the reactions of 1 with 5a – 5d smoothly proceed and give single insertion products 2a – 2d almost exclusively, the reaction mechanism will be simple and probably the concerted insertion of the germylene toward the C­(O)–Cl bonds of the acyl chlorides shown in Scheme , as suggested for the insertion reactions of the related silylene and stannylene with aroyl chlorides . Alternatively, 2a – 2d may be formed by the chlorine-abstraction of 1 from acyl chlorides giving germyl radical-acyl radical pair followed by facile coupling in cage.…”

“…Because M–Cl (M = Si, Ge, Sn) bond dissociation energies (BDE) are larger than the BDE of C–Cl bond, the reactions of silylene A and stannylene B (Chart ) with alkanoyl chlorides could also proceed in a similar manner shown in Scheme . Formation of a complex mixture from silylene A (Scheme ) suggests the intermediary chlorosilyl radical should undergo the predominant addition to carbonyl oxygens due to its higher oxophilicity than that of the germanium and tin congeners.…”

“…During the course of our study of the reactions of isolable silylene A and stannylene B (Chart ) with various reagents, we have found the facile insertion of these tetrylenes into C­(O)–Cl bonds of aroyl chlorides giving the corresponding aroyl­(chloro)­silanes and -stannanes in good yields . On the other hand, the reactions of tetrylenes A and B with simple alkanoyl chlorides such as acetyl and propionyl chlorides gave quite different results from each other.…”

Unique Digoldgermanes: Structural Characteristics, Dynamic Behaviour and Distinctive Reactions

“…Acyl chlorides were also used as a chloride source to react with germylene and stannylenes, in which the corresponding acylgermanes and acylstannanes have been obtained undergoing an insertion of acyl-Cl bond. [50][51][52] While the reaction of 3a with acetyl chloride 8 was carried out at ambient temperature giving the chlorogoldgermane 9 in 67% together with acetyl(triemethylphosphine)gold (Fig. 7a).…”