Sonogashira–Hagihara reactions of halogenated glycals

• Dennis C. Koester and
• Daniel B. Werz

Beilstein J. Org. Chem. 2012, 8, 675–682, doi:10.3762/bjoc.8.75

• functionalization allowed for the mild and selective borylation of unfunctionalized glycals. Starting from persilylated glycals Ishikawa and Miyaura applied an Ir-catalyzed C–H-functionalization with B2pin2 to obtain 1-borylated glycals, such as 3, in excellent yields and selectivity. They elegantly demonstrated

• co-workers utilized 1-stannylated glycals of type 1 in a Stille cross-coupling for the synthesis of aryl-C-glycosides such as 2 (R = Ar) [14][15]. To generate these 1-substituted glycals a prefunctionalization of the pseudoanomeric carbon is mandatory. Recent advances in the field of C–H

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

• catalytic amount of phosphite–gold(I) pre-catalyst and a silver additive. Notably, the addition is regioselective for the allene terminus, and generates (E)-allylation products 202. The direct C–H functionalization of indoles or pyrroles is an efficient method for the introduction of vinyl and aryl groups

• (Scheme 53). The latter is the first example of a gold-catalyzed intramolecular C–C cross-coupling reaction involving aryl C–H functionalization with Selectfluor® as the oxidant. 2,4-Dien-6-ynecarboxylic acids 316 undergo gold-catalyzed tandem 1,6-cyclization/decarboxylation to afford 2,3-disubstituted

Synthesis of dihydrophenanthridines by a sequence of Ugi-4CR and palladium- catalyzed intramolecular C-H functionalization

• Florence Bonnaterre,
• Michèle Bois-Choussy and
• Jieping Zhu

Beilstein J. Org. Chem. 2008, 4, No. 10, doi:10.3762/bjoc.4.10

• intramolecular C-H functionalization of these adducts under ligandless conditions provided the functionalized dihydrophenanthridines (1). Conclusion Highly functionalized dihydrophenanthridines are synthesized in only two steps from readily accessible starting materials in good to excellent overall yields

• a key intramolecular C-H functionalization reaction [13][14]. As a continuation of this research program, we were interested in the synthesis of dihydrophenanthridines 1 by combined use of Ugi-4CR and a palladium-catalyzed direct CH-arylation process. The synthetic sequence we envisioned is shown in