Carboalumination Reactions

Abstract

This chapter deals with the carboalumination of alkenes and alkynes including dienes, diynes, and enynes. The zirconium‐catalyzed methylalumination of alkynes (Negishi ZMA reaction), the zirconium‐catalyzed asymmetric carboalumination of alkenes (Negishi ZACA reaction), and the cyclic carboalumination reactions of alkynes and alkenes (Dzhemilev cyclocarboalumination reaction) are discussed in great detail. The ZMA and ZACA reactions are covered in the following aspects: discovery of the reactions, synthetic methodological developments, mechanistic investigations of the reactions, and their applications in the natural product syntheses. Method developments include improvements on prototypical reactions, further transformations of the carboalumination products, and synergetic coupling of ZMA and ZACA reactions with other synthetic methods, such as palladium‐catalyzed cross‐coupling reactions. Discussion of the cyclic carboalumination is focused on the preparation of aluminacyclopentenes, aluminacyclopentadienes, and aluminacyclopentanes and their further transformations including the preparation of heterocyclic compounds containing N, O, S, Se, P, and B and interesting carbocycles. Recent studies on mechanisms of zirconium‐catalyzed carboalumination with triethylaluminum are described, which reveal multi‐pathway mechanisms leading to either a direct addition of ethyl carbon–metal bond to carbon–carbon multiple bonds or a cyclic carboalumination of alkenes and alkynes. Other metal‐catalyzed or uncatalyzed carboalumination reactions are also covered as appropriate.

Steroids Bearing Heteroatom as Potential Drugs for Medicine

“…Aluminum (Al) is a paramagnetic metal known for its high thermal conductivity, electrical conductivity, and resistance to corrosion. When exposed to oxygen, aluminum forms a strong oxide film on its surface, which protects it from further interaction with the environment [275,276]. Although aluminum has various industrial applications, such as in construction, packaging, and electrical transmission lines, its incorporation into organic compounds, particularly steroids, is not a common occurrence.…”

“…Biological activities of steroids bearing tellurium atom(268)(269)(270)(271)(272)(273)(274)(275)(276)(277)(278)(279)(280) [260].Figure 44. 3D graph illustrating the predicted and calculated activity of steroids bearing tellurium atom (271, 272, 274, 275, and 294) with a maximum of over 96% confidence, which can be used to treat Alzheimer's, Parkinson's, and other neurodegenerative diseases.…”

Uncatalyzed Carbometallation Involving Group 13 Elements: Carboboration and Carboalumination of Alkenes and Alkynes

“…The addition of organoalanes to alkenes have become powerful methods in synthetic organic chemistry because of the ready availability of organoaluminum reagents and the versatility of subsequent transformations. 70 While metal-catalyzed carboaluminations of alkenes are a common transformation, fewer examples of uncatalyzed reactions exist. 71 Efforts to develop hydroalumination led to the observation of carboalumination of alkenes.…”

Anti-Carboalumination of Alkynes Using Aluminum Trihalide and Silyl Ketene Imines: Stereo- and Regioselective Synthesis of Alkenylaluminum Compounds Bearing a Cyano Group

“…Carboalumination is a significant carbometalation reaction because aluminum is an abundant, inexpensive, and environmentally benign base metal. In particular, the carboalumination of alkynes has played an important role in industrial and pharmaceutical chemistry as well as in the total synthesis of natural products because of the versatile utility of alkenylaluminums. − However, two serious problems persist in this field (Figure A). One is that most of the established reactions are limited to syn -addition to alkynes.…”

“…Pd-catalyzed cross-coupling using alkenylaluminums is an effective method for installing alkenyl units. , Therefore, the synthesized alkenylaluminums were applied to the cross-coupling reaction with acid clorides (Scheme ). After the carboalumination of alkyne 1a using AlBr 3 and SKI 2a , propionyl chloride ( 8a ), palladium catalyst ( 9 ), and 1,4-dioxane were added to the reaction mixture.…”