Coupling, of allyl chloride

Coupling of allyl chloride with the (2 -alkenylpentafluorosilicate 463 using Pd(OAc)j as a catalyst at room temperature gives a 1,4-diene in good yields. The reaction has been applied to the synthesis of recifeiolide[299]. 

Recent trend in the synthesis of olefinic pheromones is the use of transition metal-catalyzed cross coupling reaction for carbon-carbon bond formation. Scheme 8 summarizes a synthesis of the termite trail marker pheromone, (3Z,6Z)-3,6-dodecadien- l-ol (2) by Oehlschlager [19]. The key-step is the palladium-catalyzed cross-coupling of allylic chloride A and alkenylalane B. 

Pentacoordinate silicon, in the form of allyltrichlorosilane, in the presence of DMF or HMPA, also undergoes allylation with aldehyde [97,98], The Lewis base-promoted approach has the merit of operational convenience. Stereoselective formation of allylic trichlorosilanes is achieved by copper-catalyzed coupling of allylic chloride and trichlorosilane or by palladium-catalyzed hydrosilylation of 1,3-dienes (Sch. 56) [99],... 

Preparation. Allylchlorosilanes are conveniently obtained by cross-coupling of allyl chloride with polychlorosilanes in dimethylimidazolidinone using zinc as mediator. 

Coupling of allylic compounds [1, 722-723, before references] revision and extension. Bauld s observation of the coupling of allylic acetates by Ni(CO)4 cited in ref. 12 was preceded by the discovery of Webb and Borcherdt14 (du Pont) in 1951 that nickel carbonyl in methanol effects coupling of allylic chlorides in excellent yield, for example ... 

The palladium-catalyzed cross coupling of allyl chloride 6 with vinyltributyltin occurs with net retention of configuration if the reaction is conducted under conditions that favor oxidative syn addition4, though the degree of stereoselectivity is somewhat lower than for its catalytic phenylation using a tin reagent (see Table 27). 

COUMARILIC ACID, 24, 33 Coumarin, 24, 33 Coumarin dibromide, 24, 33 Coumarin, 4-methyl-, 24, 69 Coupling, of allyl chloride, 27, 7 of aryl residues, 20, 45 Crab shells, 26, 36 Creatinine, 22, 90 /i-Cresol, 2-bromo-, 23,11 Crotonaldehyde, 24, 92 27, 66 Crotonic acid, SO, 101 24, 98 26, 55 Crotonio acid, /3-anilino-, ethyl ESTER, 29, 42 Cupric acetate, 28, 45 Cupric carbonate, basic, 24, 64 Cupro-cupri sulfite, 28, 53 Cuprous bromide, 24, 22, 23 Cuprous chloride, 28, 46 Cuprous cyanide, 21, 89 24, 14, 97 28, 34... 

Application of this reaction to a,ct)-bisallylic halides makes the synthesis of medium and large rings possible. Treatment of l,l-bis(chloromethyl)-ethylene (CVII) with nickel carbonyl in tetrahydrofuran gives the dimer CVIII and trimer CIX in 11 and 54% yield, respectively (Corey and Sem-melhack, 1966). These products are derived by intermolecular coupling, followed by intramolecular coupling of allylic chlorides. The nine-membered carbocycle (CIX) was produced by the coupling of CVn and the dichloride... 

The coupling of allylic chlorides with trimethylsilylalkynes in the presence of [PdCl2(PhCN)a] also exhibits good regio- and stereo-selective control to give 4-trimethylsilyl-5-chloro-l,4( )-dienes. Furthermore, upon treatment with fluoride, these produce the corresponding 1,4-enynes. Dicyclopentadienylzirconium diene complexes are readily carbonylated, and the adducts, after hydrolysis with acid, afford cyclopent-3-enones, sometimes in synthetically useful yields. ... 

In a similar manner, three-component coupling of allyl chlorides or acetates with 1-alkynes and alkynyltins in the presence of a nickel catalyst prepared in situ from Ni(acac)2 and DIBALH provides a convenient regio- and stereoselective synthesis of 3,6-dien-l-ynes [231,232], It is interesting to note that no phosphine ligands are required in these reactions. A Jt-allylnickel intermediate is proposed. 

Organoboranes are reactive compounds for cross-coupling[277]. The synthesis of humulene (83) by the intramolecular cross-coupling of allylic bromide with alkenylborane is an example[278]. The reaction of vinyiborane with vinyl-oxirane (425) affords the homoallylic alcohol 426 by 1,2-addition as main products and the allylic alcohol 427 by 1,4-addition as a minor product[279]. Two phenyl groups in sodium tetraphenylborate (428) are used for the coupling with allylic acetate[280] or allyl chloride[33,28l]. 

COUPLING OF ALLYLIC HALIDES WITH TRIBUTYLTIN CHLORIDE ... 

Nozaki-Hiyama-Kishi (NHK) reactions215,216 are well known and often employed as a useful method for the synthesis of natural products by coupling of allyl, alkenyl, alkynyl, and aryl halides or triflates with aldehydes. The organochromium reagents are prepared from the corresponding halides or triflates and chromium(ll) chloride, and are employed in polar aprotic solvents (THF, DMF, DMSO, etc.). Subsequently, it was found that nickel salts exhibited a significant catalytic effect on the formation of the C-Cr bond217,218 (Equation (19)). 

Lithiation of the vinylstannane moiety of 22 with BunLi followed by the reaction with PhCHO gives (Z)-7-silyl allylic alcohol 23 (Scheme 65).261 The subsequent Cu(i)-mediated cross-coupling with allyl chloride affords (Z)-allylic alcohol 24 with the (Z)-stereochemistry retained. 

TMEDA, coupling with allyl chlorides requires slight heating over a period of two hours (equation 45). 

In a similar manner, Lu and Liu have more recently utilized the hetero-Michael addition of lithium propargylic alkoxides to alkylidene malonates in a synthesis of stereodefined allylidene tetrahydrofurans, based on the use of allylic chloride as coupling partner [98]. In this case, the cydization reaction is initiated by a catalytic amount of palladium salt [Pd(OAc)2] rather than by an organopalladium species as mentioned above. 

A further advantage is that the tin reagent is prepared in quantitative yield by coupling of tributyltin chloride and allyl chloride in the presence of Mg turnings (1 equiv.) in THF under ultrasound irradiation. 

Palladium, benzylchlorobis(triphenylphosphine)-, trans-, 67, 86 Palladium-catalyzed aryl-aryl coupling, 66, 70 PALLADIUM-CATALYZED ALLYLIC AMINATION, 67,105 PALLADIUM-CATALYZED CHLOROACETOXYLATION, 67, 105 PALLADIUM-CATALYZED COUPLING OF ACID CHLORIDES WITH ORGANOTIN REAGENTS, 67, 86 PALLADIUM-CATALYZED COUPLING OF ARYL HALIDES, 66, 67 PALLADIUM-CATALYZED syn-ADDITION OF CARBOXYLIC ACIDS,... 

Recently Ru3(CO)12 has been reported to be an effective catalyst for hydrosilylation of 1-octene [10] and of allyl chloride (Eq. 3) [11] by triethoxysilane.The latter process is of great importance for production of the main intermediate in manufacturing silane coupling agents. 

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