96094-89-2Relevant academic research and scientific papers
Carbocyclization of E,E-1,4-diphenyl-1,3-butadiene with dichloroalkanes mediated by Rieke metals
Sell,Rieke
, p. 4107 - 4113 (1995)
The Rieke metal complexes of barium and strontium readily react with E,E-1,4-diphenyl-1,3-butadiene to form metal-diene reagents. Upon treatment with 1,n-dichloroalkanes, these metallocycles are transformed into ring derivatives in excellent chemical yield.
Chemistry of Substituted (2-Butene-1,4-diyl)magnesium: A Facile Approach to Complex Carbocycles, Functionalized Ketones and Alcohols, and Silicon-Containing Heterocycles
Rieke, Reuben D.,Xiong, Heping
, p. 3109 - 3118 (2007/10/02)
Highly reactive magnesium reacts with a wide variety of substituted 1,3-dienes to give the corresponding substituted (2-butene-1,4-diyl)magnesium complexes.Reactions of symmetrical (2-butene-1,4-diyl)magnesium with α,ω-alkylene dihalides form three-, four-, five-, and six-membered carbocycles.Significantly, the cyclizations are always stereospecific and completely regioselective.Depending on the initial 1,3-diene and specific electrophiles, uncyclized products can be obtained.Stepwise reactions of (2,3-dimethyl-2-butene-1,4-diyl)magnesium with two different electrophiles afford polyfunctionalized ketones with the generation of a quaternary center.Formal 1,2-additions can be effected in this manner.Substituted five- and six-membered cyclic ketones can also be synthesized in one step by this approach.Treatment of unsymmetrical (2-butene-1,4-diyl)magnesium complexes with triorganosilyl chlorides followed by cyclohexanone results in additions across a terminal double bond with high regioselectivity.Silicon-containing heterocycles or spiro compounds can be readily synthesized by using the bis-Grignard reagents.
Organocalcium Chemistry: Preparation and Reactions of Highly Reactive Calcium
Wu, Tse-Chong,Xiong, Heping,Rieke, R. D.
, p. 5045 - 5051 (2007/10/02)
A highly reactive form of calcium was prepared by the reduction of Ca(II) salts with preformed lithium biphenylide.Remarkably, this activated calcium undergoes oxidative addition to organic bromides, chlorides, or even fluorides to form the organocalcium reagents under very mild conditions in high yields.The resulting organocalcium compounds undergo Grignard-type reactions.Transmetalation with Cu(I) salts forms calcium cuprate reagents which undergo a variety of cross-coupling reactions.The activated calcium reacts with 1,3-dienes to yield the corresponding 2-butene-1,4-diylcalcium complexes.These bis-organocalcium reagents can undergo dialkylation reactions with α,ω-alkylene dihalides and dichlorosilanes to form the corresponding 3-, 5-, and 6-membered ring derivatives.Significantly, these reactions are highly stereospecific and regioselective.
