Cross acyl chlorides

Cellulose esters of unsaturated acids, such as the acetate methacrylate, acetate maleate (34), and propionate crotonate (35), have been prepared. They are made by treating the hydrolyzed acetate or propionate with the corresponding acyl chloride in a pyridine solvent. Cellulose esters of unsaturated acids are cross-linkable by heat or uv light solvent-resistant films and coatings can be prepared from such esters. 

Previous syntheses An example of this point can be recognized by examination of one known synthesis of thienobenzazepines (Scheme 6.1). This synthetic route involves a key palladinm-catalyzed cross-conpling of stannyl intermediate 3, prepared by method of Gronowitz et al., with 2-nitrobenzyl bromide. Acetal deprotection and reductive cyclization afforded the desired thienobenzazepine tricycle 4. In support of structure activity relationship studies, this intermediate was conveniently acylated with varions acyl chlorides to yield several biologically active componnds of structure type 5. While this synthetic approach does access intermediate 4 in relatively few synthetic transformations for stractnre activity relationship studies, this route is seemingly nnattractive for preparative scale requiring stoichiometric amounts of potentially toxic metals that are generally difficult to remove and present costly purification problems at the end of the synthesis. 

Trialkylvinylstannanes undergo cross-coupling reactions with acyl chlorides, as shown by reactions 58307 and 59308. These acylations can be conducted under reductive conditions to saturate the carbon-carbon double bond, as illustrated in reaction 60309. Also... 

Iron-catalyzed cross-coupling reactions of various acyl chlorides or thioesters with Grignard reagents have been pioneered by Marchese et al. and other research groups.322 These transformations provide general and convenient access to a wide range of ketones and have been further extended to the use of a supported iron(lll) complex.323... 

Table 5.11 Range of acyl chlorides and sulfonates in iron-catalyzed cross-coupling reactions.

Lithiation of compound 560 with s-BuLi-TMEDA in THF at —78 °C following an inverse addition protocol provided the anion 561. It reacts with primary alkyl iodides and triflates, silyl chlorides, diphenyl disulfide, epoxides, aldehydes, ketones, imines, acyl chlorides, isocyanates and sulfonyl fluorides to yield the expected compounds 562 (Scheme 152). The transmetallation of compound 561 with ZnBr2 allowed the palladium-catalyzed cross-coupling reaction with aryl and vinyl bromides837. When the reaction was quenched with 1,2-dibromotetrafluoroethane, the corresponding bromide 562 (X = Br) is obtained838. 

Mg-promoted Reductive Cross-coupling of a,) -unsaturated Carbonyl Compounds with Aldehydes or Acyl Chlorides... 

Differently cross-linked poly(methyl methacrylate) (PMMA) (137) has been employed for the synthesis of supported hydroxamic acids 138 after treatment with hydroxylamine, and reacted with acyl chlorides in the presence of pyridine to give the supported hydroxamic acid esters 139, which are suitable as solid acyl transfer reagents when reacting with alkyl and aryl amines (Scheme 7.42) [143]. 

Indane-l,3-diones 44 can be synthesized by a three-component sequential aluminum-chloride-promoted cross condensation-cycloacylation of various acyl chlorides (Scheme 2.20). Thus, the poorly stable acetoacetyl chloride 41, produced in situ by aluminum chloride-promoted self-condensation of acetyl chloride, reacts at the methylene active carbon with aromatic acyl chlorides 42, giving the reactive complexes 43 that... 

The stannane-acyl chloride cross-coupling has been directed towards access to 3-acylcyclobutenones and a-heterosubstituted ketones. ... 

Several N-protected indol-2-yltributylstannanes were examined in Pd-catalyzed cross-coupling with aryl halides and triflates, acyl chlorides and benzylic and allylic bromides. <94J0C4250> The 1-methyl and l-(2-trimethylsilylethoxymethyl) (SEM) derivatives reacted readily whereas the 1-t-butoxycarbonyl derivative was somewhat less reactive. The SEM group is removable with BU4N F , providing acces to the deprotected 2-substituted indoles. 

Hexamethyl- and Hexabutylditin. These ditins undergo cross-coupling with a variety of organohalides and pseudohalides (such as aryl halides, vinyl triflates, acyl chlorides, and allyl halides) in this protocol to give the correponding tin compounds. The reaction is particularly useful for preparation of organotins with labile functionalities that are not compatible with other procedures. 

Organolead compounds as a substrate for the Pd-catalyzed cross-coupling was reported in 1987 by Yamada and Yamamoto , who observed tetraalkylleads coupled with various acyl chlorides (Scheme 48). Two alkyl groups on lead are considered to be utilized for the reaction, because the use of 0.3 equiv of tetraalkyllead lowered the yield. 

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