The chemoselective and complementary Pd-and Cu-catalyzed N-arylation of 2aminobenzimidazoles is described. Selective N-arylation of the amino-group was achieved with a Pd-catalyzed method, while selective N-arylation of azole nitrogen was achieved with a Cucatalyzed procedure. The utility of these complementary sets of conditions is demonstrated in several two-step, selective syntheses of di-ar...

1-Hydroxycarbazole-2,3-dicarboxylates have been shown to undergo chemoselective reductive cyclization to furo[3,4-b]carbazolones on reaction with LiAlH4. One of the furocarbazolones is utilized to accomplish the first total synthesis of claulansine D and mafaicheenamine E in 9 and 6 steps respectively. The other key steps of the syntheses are addition of an allylic indium reagent and CC double ...

Diaryliodonium salts are demonstrated as efficient arylating agents of aliphatic alcohols under metal-free conditions. The reaction proceeds at room temperature within 90 min to give alkyl aryl ethers in good to excellent yields. Aryl groups with electron-withdrawing substituents are transferred most efficiently, and unsymmetric iodonium salts give chemoselective arylations. The methodology has...

We report a concise synthesis of A-factor, the prototypical γ-butyrolactone signalling compound of Streptomyces bacteria. In analogy to enzymatic reactions in A-factor biosynthesis, our synthesis features a tandem esterification-Knoevenagel condensation yielding a 2-acyl butenolide and a surprising, chemoselective conjugate reduction of this α,β-unsaturated carbonyl compound using sodium cyanob...

A palladium-catalyzed regio- and chemoselective direct benzylation of primary benzamides with 2-bromobenzyl bromides under a mild basic condition has been developed affording various substituted diarylmethanes in good yields. Furthermore, the directing amide group (-CONH2) was subjected to intramolecular N-arylation with the aryl bromide moiety present in diarylmethanes leading to a concise syn...

1,2-Dipole Tf2C=CH2 is generated in situ and immediately reacts at room temperature with an azide to afford previously unknown 4-trifluoromethanesulfonyl 1,2,3-triazoles through a stepwise [3+2] cycloaddition reaction. Noteworthily, this mild and powerful uncatalyzed protocol is highly regio- and chemoselective.

A well-defined cationic Ru-H complex catalyzes reductive etherification of aldehydes and ketones with alcohols. The catalytic method employs environmentally benign water as the solvent and cheaply available molecular hydrogen as the reducing agent to afford unsymmetrical ethers in a highly chemoselective manner.

Chemoselective Suzuki-Miyaura reactions on 3,5-dibromo-2,6-dichloropyridine were studied. The optimized reaction conditions allow for the facile access of 3-aryl- and 3,5-diarylpyridines in good yields. Suzuki-Miyaura reactions of the selectively synthesized 2,6-dichloro-3,5-diarylpyridines gave the corresponding 2,3,5,6-tetraarylpyridines, containing two different aryl moieties.

A flexible and divergent synthesis of cryptophycin unit A analogues is described. This method relies on iridium-catalysed stereo- and enantioselective crotylation and chemoselective one-pot oxidative olefination to access common intermediate . Heck, cross metathesis, and Suzuki-Miyaura reactions are illustrated for the generation of methyl ester unit A analogues .

An operationally simple iron-catalyzed hydrodehalogenation of aryl halides has been developed with 1 mol% Fe(acac)(3) and commercial t-BuMgCl as reductant. The mild reaction conditions (THF, 0 degrees C, 1.5 h) effect rapid chemoselective dehalogenation of (hetero)aryl halides (I, Br, Cl) and tolerate F, Cl, OR, SR, CN, CO(2)R, and vinyl groups.