We have developed an innovative strategy for the formation of angular carbocycles via a gold(I)-catalyzed dehydro Diels-Alder reaction. This transformation provides rapid access to a variety of complex angular cores in excellent diastereoselectivities and high yields. The usefulness of this Au -catalyzed cycloaddition was further demonstrated by accomplishing a 11-steps total synthesis of (±)-magellanine.

During our efforts toward the synthesis of naturally occurring polyprenylated polycyclic acylphloroglucinol using a Au(I)-catalyzed 6-endo dig carbocyclization, we isolated stable vinyllic gold intermediates. Optimization lead to isolated yields of up to 98%, using 2-(di-tert-butylphosphino)biphenyl as the ligand. This transformation is derived from a silyl rearrangement that can be fully controlled according to the nature of the substituent on the ynone. This selective transformation does not require basic conditions to prevent protodeauration. These vinylgold complexes are the first isolated intermediates during a silyl migration with gold(I). More than 16 new organogold complexes were synthesized and characterized by single-crystal X-ray diffraction. Reactivity of these complexes is also presented.

For many years, gold was considered inactive to catalyze organic transformations. In the last two decades, gold(I/III) complexes have emerged as efficient catalyst for the formation of C−O, C−N and C−C bonds. In particular, monomeric organogold complexes whose binding affinity for alkenes, allenes and alkynes opened new directions in organic synthesis. More recently, dimeric gold species were used as photocatalyst in light‐enabling processes. Taking advantage of the gold unique reactivity, we describe the development of novel transformations catalyzed by gold and their applications in the synthesis of natural products.

We have developed an innovative strategy for the formation of angular carbocycles via ag old(I)-catalyzed dehydro Diels-Alder reaction. This transformation provides rapid access to avariety of complex angular cores in excellent diastereoselectivities and high yields.T he usefulness of this Au I -catalyzed cycloaddition was further demonstrated by accomplishing a1 1-steps total synthesis of (AE)-magellanine. Scheme 3. Total synthesis of magellanine 7.Reagents and conditions: a) TMAD, TBP, 19, o-xylene, 0 8 8C; then BHT 150 8 8C. b) OsO 4 ,NMO, NaIO 4 , THF:H 2 O, 20 8 8C. c) Piperidine, AcOH, PhMe, 20 8 8C. d) TIPSOTf, DMS, LiHMDS, THF, À78 8 8C. e) [L6AuNCMe][SbF 6 ](1mol %) PhMe, 20 8 8C; then CSA (1 equiv). f) TBAF, 60 8 8C; then LiOH, H 2 O/THF, 140 8 8C. g) DMP, DCM, 20 8 8C. h) PtO 2 ,H 2 ,E tOAc, 20 8 8C. i) i-PrCO 2 Cl, NMM, Et 3 N, 25,P hMe, 0 8 8C; then 365 nm LED, O 2 , tert-dodecylmercaptan, 0 8 8C; then PPh 3 .j )DIAD, HCO 2 HPPh 3 ,THF;then LiOH. k) Na, naphthalene, THF, À78 8 8C; then AcOH, formaldehyde, NaBH 3 CN, 20 8 8C. l) LDA (2 equiv),T MSCl (1 equiv), 30,THF, 0 8 8C; then HCl, 20 8 8C. TMAD = tetramethyl azodicarboxamide, TBP = tributylphosphine, BHT = butylated hydroxytoluene, NMO = N-methylmorpholine N-oxyde, THF = tetrahydrofuran, TIP-S = triisopropylsilyl, DMS = dimethyl sulfide, CSA = camphorsulfonic acid, TBAF = tetrabutylammonium fluoride, DMP = Dess-Martin periodinane, DCM = dichloromethane, NMM = N-methylmorpholine, DIAD = diisopropyl azodicarboxylate, LDA = lithium diisopropylamide, TMS = trimethylsilyl.

The formal synthesis of (�)-salvinorin A is presented. Our approach utilizes two distinct gold(I) catalytic processes. The combination of a gold(I)-catalyzed reaction with an intermolec-ular Diels-Alder reaction followed by a gold(I)-catalyzed photoredox reaction generated in eight steps the framework of the natural product with high diastereoselectivity.