A)three and H8BINOL-derived phosphorus amidite ligand L9 (Scheme 10).22 A range
A)3 and H8BINOL-derived phosphorus amidite ligand L9 (Scheme 10).22 A number of readily available terminal olefins might be efficiently C-H diaminated, providing the corresponding imidazolidinones in excellent yields with high diastereo- and enantioselectivities. The C-H diamination likely proceeds by way of in situ formed diene intermediate 8 (Scheme 11).21,22 The terminal olefinScheme 15. Pd(0)-LIMK1 Accession Catalyzed Dehydrogenative Diamination Usingcoordinates with four-membered Pd(II) species 10, resulting from the oxidative insertion of Pd(0) in to the N-N bond of ditert-butyldiaziridinone (1) to form complex 23. -Allyl Pddx.doi.org10.1021ar500344t | Acc. Chem. Res. 2014, 47, 3665-Accounts of Chemical Investigation Scheme 16. Diamination using a Mixture of (E)-1,3Pentadiene (8b) and 1-Nonene (22b) Scheme 18. Cyclization of Sulfamide 37aArticleScheme 19. Pd(0)-Catalyzed Sequential Allylic and Aromatic C-H Aminations withcomplex 24, generated from 23 via allylic hydrogen abstraction, mAChR2 review undergoes a -H elimination to provide diene eight and regenerate the Pd(0) catalyst. The resulting diene is subsequently diaminated under the reaction situations. Bisdiamination can also be realized for substrates obtaining two terminal double bonds, major to stereoselective construction of four C-N bonds in one step with formal replacement of four sp3 C-H bonds (Schemes 12 and 13).22 Using the asymmetric C-H diamination procedure, potent and selective substance P receptor antagonist ()-CP-99,994 (32) was synthesized in 20 all round yield and 99 ee from readily accessible 4-phenyl1-butene (22a) (Scheme 14).23 As illustrated inside the case of imidazolidinone 30, among the list of tert-butyl groups may be selectively removed, enabling ready differentiation from the two nitrogens. Interestingly, with di-tert-butylthiadiaziridine 1,1-dioxide (two) because the nitrogen supply, the terminal olefin underwent a dehydrogenative diamination rather than the allylic and homoallylic C-H diamination, giving cyclic sulfamide 33 in very good yield (Scheme 15).24 When the diamination was carried out using a mixture of (E)-1,3-pentadiene (8b) and 1-nonene (22b), internal cyclic sulfamide 21a and terminal cyclic sulfamide 33a, respectively, were formed (Scheme 16), suggesting that the dehydrogenative diamination didn’t proceed via a diene intermediate as inside the case of di-tertbutyldiaziridinone (1) (Scheme 11). A plausible reaction mechanism is outlined in Scheme 17.24 Four-membered Pd(II) species 34 is initially generated through the oxidative addition of Pd(0) to the N-N bond of di-tertbutylthiadiaziridine 1,1-dioxide (2). The coordination of theterminal olefin (22) to 34 forms complex 35, which undergoes an allylic hydrogen abstraction to produce -allyl Pd complex 36. The reductive elimination of 36 gives allyl sulfamide 37 and regenerates the Pd(0) catalyst. Allyl sulfamide 37 undergoes a subsequent Pd(II)-catalyzed cyclization to form intermediate 39, which can be converted into sulfamide 33 with regeneration of the Pd(0) catalyst after a -hydride elimination and reductive elimination. In this method, -allyl Pd complicated 36 preferentially undergoes a reductive elimination instead of a -hydride elimination as inside the case of intermediate 24 (Scheme 11), likely since the sulfamide group of 36 is additional electrondeficient than the urea group of 24. When preformed allyl sulfamide 37a was subjected to the reaction circumstances, cyclic sulfamide 33a was certainly formed (Scheme 18),24 further supporting the proposed mechanism. Treating -methylstyrenes wit.