Nysted Reagent Literature Refernces
Literature references for the use of the Nysted:
Furstner, A. (2003) J. Am. Chem. Soc. 125:15512.
Amphidinolide
[trans-2, 5-disub tetrahydrofuran (std ester Dibal reduct prim alcohol TsCl for KCN CN- tosylate displ nitrile 9; aldehyde asymm Brown Ipc2Ballyl allylation; lactol hemiacetal PhSO2H CaCl2 sulfone; propionate Evans propionyloxazolidinone Bu2BOTf syn aldol add enal methacrolein 13 MOMCl protect; acyloxazolidinone LiBH4 reduct cleave 15 TBDMSOTf; exocyclic methylene O3 PPh3 quench methylketone ketone TBSOTf NEt3 silylenolether 18; propionate Evans NaHMDS allylbromide C-allylation 20; std Noyori asymm b-ketoester RuCl2 BINAP hydrogenation reduct; EDC carbodiimide DMAP esterification ester 23; tBu ester TFA Et3SiH cleave; std carboxylate (COCl)2 DMF acylchloride; oxocarbenium SnCl4 silylenolether trap strong tetrahydrofuran envelope conformation control inside trajectory Sch 6; distereo ketone Selectride reduct 26 contrast opposite stereo combine LiI LAH see chelate hydride reduct structure H & I; unexpect prim alcohol I2 PPh3 cyclize tetrahydrofuran 29 w participation of O-PMB protect ether w loss dePMB, NMR cis assign; sec alcohol TBDPSCl O-TBDPS req KHMDS base 30; prim iodide Zn/Cu couple [TMSCl activate) derive alkylyzinc for acyl Negishi rxn acylchloride to ketone 33; RCM macrocyclization; steric hinder ketone methylenation req mod Nysted TiCl4 64% other meth incl Wittig Peterson fail, Takai yield too variable; v mild deTBDPS w Roush [(Me2N)S][Me3SiF2] 39 see ref 39; Dowex MeOH deMOM but in situ TMSBr [fr TMSCl Bu4NBr] better; unusual Zn/Cu SET radical cascade cyclize in acyl-Negishi 46; reflux PhMe for success methathesis disc thermal stability RCM cat 48; disc hinder rotation O-MOM NMR invisible req t depend to see 48 49; std Dess-Martin]
Paquette, L. A. (2004) J. Org. Chem. 69:2454.
Cyclic ketone cycloheptanone protect via Nysted TiCl4 methylenation exocyclic methylene allow a-hydroxyketone IBX oxidat enone for diastereo Luche CeCl3 NaBH4 reduct (cyclic epoxide TfOH DMSO oxidat rearrange ketol; ketone LiHMDS mCPBA & O2 P(OEt)3 oxidat a-hydroxyketone 22; alkene O3 oxidat cleave ketone; cyclic diketone Zn dust NH4Cl reduct ketol see Scheme 7)
Clark, J. S. (2004) Org. Lett. 6:1773.
Gambieric antifungal A-ring via intramol a-diazoketone Cu(acac)2 reflux allylether insert to 2, 5-trans-sub 3-tetrahydrofuranone ketone Nysted methylenation methylene Wilkinson RhCl(PPh3)3 hydrogenation reduct to 3-methyl sub tetrahydrofuran (std ester KOTMS Et2O hydrolysis carboxylate (COCl)2 acylchloride CH2N2 a-diazoketone)
Crich, D. (2006) J. Am. Chem. Soc. 128:8078.
Stereocontrol syn D & L-glycero-b-D-manno Hep Hepp LPS heptopyranoside
gen disc LPS inner outer core saccharide; vaccine oligosaccharide; disc reduct radical fragment cleave 4,6-benzylidene acetal Sch 1 to 6-deoxy, see also a-cyano-o-iodophenethyl Bu3SnH AIBN w NaBH4 work-up to remove tin residue 45 & 57; std Dibal [or Sc(OTf)3 BH3 to 6-hydroxy Swern 6-aldehyde [unstable!] Wittig ethylidene OsO4 NMO dihydroxylation, Kishi rule assign; SAD fail; disc compete fragment rxn w Wittig, Nysted also satisfactory but Petasis fail; sec alcohol std O2NBz Mitsunobu inversion; opt 5-O-PMB DDQ oxidat acetalization acetal, CSA equilibrate; std TBDPSCl O-TBDPS; 2-O-Bn mannose type a-thioglycoside Crich BSP TTBP Tf2O b-mannoside, J NMR assign; acetonide CSA MeOH reflux hydrolysis; select 2-hydroxy mannose rhamnose Bu2SnO allylbromide CsF direct O-allylation rhamnoside, BnBr O-Bn O-benzylation 37 see also 50; opt aldehyde hydroxymethylation Tab 3 incl BnOCH2Cl Mg HgBr2 other; TFA de-O-PMB dePMB; van Boom BSP Tf2O 60 glycosylation; Pd(OH)2 hydrogenation per-O-deBn debenzylation 64; Table 4 anomeric 1H 13C NMR
|