Recent advances in direct C–H arylation: Methodology, selectivity and mechanism in oxazole series
- Cécile Verrier,
- Pierrik Lassalas,
- Laure Théveau,
- Guy Quéguiner,
- François Trécourt,
- Francis Marsais and
- Christophe Hoarau
Beilstein J. Org. Chem. 2011, 7, 1584–1601, doi:10.3762/bjoc.7.187
Graphical Abstract
Scheme 1: Stoichiometric and catalytic direct (hetero)arylation of arenes.
Scheme 2: Stille and Negishi cross-coupling methodologies in oxazole series [28,30,31,33,34].
Scheme 3: Stoichiometric direct (hetero)arylation of (benz)oxazole with magnesate bases [35].
Scheme 4: Ohta's pioneering catalytic direct C5-selective pyrazinylation of oxazole [36,37].
Scheme 5: Preparation of pharmaceutical compounds by following the pioneering Ohta protocol [38,39].
Scheme 6: Miura’s pioneering catalytic direct arylations of (benz)oxazoles [40]. aIsolated yield.
Scheme 7: Pd(0)- and Cu(I)-catalyzed direct C2-selective arylation of (benz)oxazoles [41-44].
Scheme 8: Cu(I)-catalyzed direct C2-selective arylations of (benz)oxazoles [40,45-47].
Scheme 9: Copper-free Pd(0)-catalyzed direct C5- and C2-selective arylation of oxazole-4-carboxylate esters [48-50,52].
Scheme 10: Iterative synthesis of bis- and trioxazoles [51].
Scheme 11: Preparation of DPO- and POPOP-analogues [53].
Scheme 12: Pd(0)-catalyzed direct arylation of benzoxazole with aryl chlorides [54].
Scheme 13: Pd(0)-catalyzed direct C2-selective arylation of (benz)oxazoles with bromides and chlorides using b...
Scheme 14: Palladium-catalyzed direct arylation of oxazoles under green conditions; (a) Zhuralev direct arylat...
Scheme 15: Pd(0)-catalyzed C2- and C5-selective (hetero)arylation of oxazole [63].
Scheme 16: Pd(0)-catalyzed C2- and C5-selective (hetero)arylation of ethyl oxazole-4-carboxylate [64].
Scheme 17: Pd(0)-catalyzed direct C4-phenylation of oxazoles; (a) Miura’s procedure [65]; (b) Fagnou’s procedure [66].
Scheme 18: Catalytic cycles for Cu(I)-catalyzed (routeA) and Pd(0)/Cu(I)-catalyzed (route B) direct arylation ...
Scheme 19: Base-assisted, Pd(0)-catalyzed, C2-selective, direct arylation of benzoxazole proposed by Zhuralev [58]...
Scheme 20: Electrophilic substitution-type mechanism proposed by Hoarau [64].
Scheme 21: CMD-proceeding C5-selective direct arylation of oxazole proposed by Strotman and Chobabian [63].
Scheme 22: DFT calculations on methyl oxazole-4-carboxylate and consequently developed methodologies for the P...
Scheme 23: Pd(0)-catalyzed direct arylation of (benz)oxazoles with tosylates and mesylates [71].
Scheme 24: Pd(0)-catalyzed direct arylation of oxazoles with sulfamates [72].
Scheme 25: Pd(II)- and Cu(II)-catalyzed decarboxylative direct C–H coupling of oxazoles with 4- and 5-carboxyo...
Scheme 26: Pd(II)- and Ag(II)-catalyzed decarboxylative direct arylation of (benzo)oxazoles [74]; (a) procedure; (...
Scheme 27: Pd(II)- and Cu(II)-catalyzed direct arylation of benzoxazole with arylboronic acids [76]; (a) procedure...
Scheme 28: Ni(II)-catalyzed direct arylation of benzoxazoles with arylboronic acids under O2 [76]; (a) procedure; ...
Scheme 29: Rhodium-catalyzed direct arylation of benzoxazole [78,79].
Scheme 30: Ni(II)-catalyzed direct arylation of (benz)oxazoles with aryl halides; (a) Itami's procedure [80]; (b) ...
Scheme 31: Dehydrogenative cross-coupling of (benz)oxazoles; (a) Pd(II)- and Cu(II)-catalyzed cross-coupling o...
