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Ethyl (2 E ,4 E )-3-trifluoromethyl-2,4-dienoates 1a – e and ethyl ( E )-3- trans -alkylcyclopropyl-4,4,4-trifluoro-2-butenoates 2a – e were prepared from the trans -alkenylboronic acids 3a – e and the trans -cyclopropylboronic acids 4a – e with ethyl ( Z )-3-iodo-4,4,4-trifluoro-2-butenoate ( 5 ) by the Suzuki cross-coupling reaction in high yields (88–95%). The configurations of both 3a – e or 4a – e and 5 were retained in the reaction.

Aryl amides were synthesized by the palladium catalyzed cross-coupling reaction of α-bromoacetamides with arylboronic acids in good yields. Both electron-donating and electron-withdrawing substituents on the aromatic ring are found to be compatible. The addition of Cu 2 O and PPh 3 was found to be essential for good reaction yields.

Stereodefined cyclopropyl substituted acrylate esters were selectively reduced to the corresponding propionate esters by sodium borohydride in methanol/DMF with a catalytic amount of CoCl 2 without the opening of the cyclopropane ring. The configuration and chirality of the stereodefined cyclopropyl function were retained in the reaction. Combined with the cross-coupling reaction of stereodefined cyclopropylboronic acids with bromoacrylate esters or alkenyl triflates, the reaction method provides a novel route to stereodefined 3-cyclopropyl propionate ester, an important subunit existing in a wide range of natural compounds.

The first palladium-catalyzed cross-coupling reaction between substituted arylboronic acids and chloroformate or carbamoyl chloride is described. One-carbon homologation from arylboronic acids was achieved to give corresponding esters or amides in good yields.

The reactions of 2-chloromethylthiophene (an analog of a benzyl halide) with lithium trialkylalkynylborates gave, after protonation, E-alkenes with a (2-thenyl) substituent in good yields, and the reaction stereo-selectivity was different from that of the reaction of benzyl bromide with an alkynylborate.

Optically active cyclopropanes (e.g. 1) can be prepared by the use of tartaric acid derivatives as chiral auxiliaries in the palladium-catalyzed cross-coupling of optically active cyclopropylboronic acids with electrophiles. The absolute configuration of the chiral carbon atom is retained, and the reaction proceeds with good yields and enantiomeric excesses. R=H, p-Ph, o-CO2 CH3 , p-CO2 CH3 , p-NO2 , o-OCH3 , m-OCH3 .

Copper(I) oxide can effectively co-catalyze the Suzuki type cross-coupling reactions of arylboronic acids with ethyl bromoacetate. As an alternative protocol for introducing the methylenecarboxy group into functionalized molecules, this reaction occurs in the absence of highly toxic thallium compounds or special ligands and should be convenient and practical.

The stereocontrolled dehydrobromination of 1,2-dibromoethyl carboxylates giving (Z)-2-bromovinyl carboxylates could readily be approached by using DBU and a catalytic amount of hydroquinone as a base at −78 °C. The first investigation on the Suzuki-type cross-coupling of (Z)-2-bromovinyl carboxylates as electrophiles with stereodefined alkenylboronic acids provides a novel method for the construction of (Z,E)- or (Z,Z)-conjugated alkadienyl carboxylate moieties, which are often present in a range of natural products.

A simple and efficient synthesis of N-sulfonyl ketimines through a Pd-catalyzed cross-coupling reaction between organoboronic acids and tosylbenzimidoyl chlorides under mild conditions has been developed.

4-Substituted 1,2-oxaborol-2(5H)-ols were prepared through copper-catalyzed carbomagnesation of propargyl alcohol, followed by the transmetallation of magnesium to boron in a one-pot procedure. The Suzuki-Miyaura cross-coupling of these new 2,2-disubstituted alkenylboronic acids with aryl halides afforded stereodefined 2,3-disubstituted allyl alcohols in good to excellent yields.

The effect of coordination on the reaction of N-tosyl imines and diethylzinc was studied in detail. It showed that there was strong coordination between N-tosyl imine and diethylzinc. Due to this coordination, N-tosyl imines could be reduced directly through the β-H transferring mechanism by diethylzinc in nonpolar solvents to afford the corresponding secondary amines in excellent yields at mild conditions. The coordination of diethylzinc and N-tosyl imine was hindered by reacting in polar solvents or adding TMEDA to the reaction, it afforded ethylating product partially or exclusively.

The Suzuki–Miyaura type cross‐coupling reactions of various chloropyrimidines with stereodefined alkenylboronic acids giving the corresponding alkenyl‐substituted pyrimidines were studied. The experiments discovered that the reaction is stereospecific and highly regioselective. In the coupling of 2,4‐dichloropyrimidine and 2,4,6‐trichloropyrimidine, the reaction occured at 4‐position prior to 2‐position.

[reaction: see text] Stereospecific cyclopropanation of alkenylboronic esters of pinacol followed by in situ treatment with excess KHF(2) afforded the corresponding potassium cyclopropyl trifluoroborates in high yields, which then underwent Suzuki-Miyaura cross-coupling reactions with aryl bromides to give cyclopropyl-substituted arenes in good yields with retention of configuration. This promises to be a useful method for the synthesis of enantiomerically pure cyclopropanes.

A novel method for the synthesis of stereodefined cyclopropyl-substituted alkenes, based on the Suzuki-type cross-coupling reaction between cyclopropylboronic acids and various alkenyl triflates, is described. It was found that the environment of the alkenyl triflate plays an important role in the reaction, and that the use of an appropriate base can make the reaction proceed readily to give stereodefined cyclopropyl-substituted alkenes in good to high yield.

In the presence of Pd(PPh3)4, NaBr and KF·2H2O the cross-coupling reaction of heteroaryl triflates with trans-cyclopropylboronic acids proceeds readily to give pure trans-cyclopropyl heteroarenes in moderate to good yields. The X-ray crystallography of compound 3g and 1H-NMR spectra of all products show that the configuration of the cyclopropyl group was retained during the reaction. Under the same reaction conditions, highly optically active cyclopropyl-substituted heteroarenes (up to 94% ee) were obtained by cross-coupling of heteroary/triflates with enantiomerically enriched cyclopropylboronic acids.

The palladium-catalyzed cross-coupling reaction of cyclopropylboronic acids with acyl chlorides was achieved by the combination of Ag2O and K2CO3 as the base. Highly enantiomerically enriched cyclopropyl ketones (ee >90%) were also obtained by the reaction of corresponding chiral cyclopropylboronic acids.