Ring-closing diene metathesis

Ring-Closing Diene Metathesis 11.07.2.1 Formation of Five-, Six-, and Seven-membered Rings... 

Metathesis reactions may be intramolecular and ring-closing diene metathesis (RCM, implicated in Scheme 1.13, see Chapter 12) allows disconnections in retro-synthetic analysis otherwise of little use. The normal disconnection of the macrocyclic amide in Scheme 1.13 would be at the amide but, because of the ready reduction of alkenes to alkanes, the alternative disconnection now becomes a viable option. And since any of the C—C linkages could be formed by RCM, such a disconnection allows far greater synthetic flexibility than the conventional disconnection at the functional group. 

With the advances in pro-catalyst design that have been witnessed over the last decade or so, the transition-metal-catalysed alkene metathesis reaction has now become a practical procedure that can be utilised by the chemist at the bench. Undeniably, this has added a new dimension to the repertoire of synthetic organic chemistry as it facilitates disconnections that, pre-metathesis, simply would not have been considered. Take, for example, a macro-cyclic amide where the normal disconnection would be at the amide. Now, with the ready reduction of alkenes to alkanes, a ring-closing diene metathesis (RCM), followed by hydrogenation, becomes an alternative disconnection. And, when one considers that any of the C—C linkages could be established in such a manner, the power of the RCM disconnection becomes obvious. 

Scheme 12.18 Theco-RCM (ring-closing diene metathesis) of a 1.21 1.00 ratio of Do and 1,1,1,10,10,10-D6-Z,Z-deca-2,8-diene see the text for full details.

Allosedamine, via ring-closing diene metathesis, 11, 224-225 Allyamines, isomerization, 10, 71 Allyindation reactions, alkenes and alkynes, 9, 693 Allyl acetals... 

Aluminum—tetradentate ligand catalyst system, in epoxide homopolymerization, 11, 601 Aluminum(I) tetrahedra, synthesis, 9, 262 Aluminum(III)-tin exchange, process, 9, 265 Aluminum-transition metal bonds, characteristics, 9, 264 Amavadine, for alkane carboxylations, 10, 234—235 Ambruticin S, via ring-closing diene metathesis, 11, 218 Amide-allenes, cyclizations, 10, 718 Amide ether complexes, with Zr(IV) and Hf(IV), 4, 783 Amide hybrid ligands, in organometallic synthesis, 1, 64 Amides... 

Antimony—metal complexes, characteristics, 2, 34 Anti-proliferation drugs, for parasites, 12, 458 159 Anti-tumor effects, Ti(IV) complexes, 4, 662 (—)-Antofine, via ring-closing diene metathesis, 11, 222 (t-)-Aphanomol 1, via [5+2]-cycloadditions, 10, 613-614 Apical ligands, iron complexes with, 6, 313 Aqua ligands... 

BPE, and chiral bisphosphane ligands, 10, 7 (+)-Brasilenyne, via ring-closing diene metathesis, 11, 221 Breast implants, silicone applications, 3, 680 Brevetoxin B, via ring-closing diene metathesis, 11, 237 m -Brevicomin, synthesis, 9, 13... 

Callipeltoside A, via Alder-ene reactions, 10, 593 Calorimetry, in thermochemistry, 1, 610-611 Calystegine B2, via ring-closing diene metathesis, 11, 210-211 Cambridge Structural Database, in structure determination,... 

Carbacycles, via ring-closing diene metathesis large-sized, 11, 208 medium-sized, 11, 227 Carbamates, in semiconductor growth, 12, 27 Carbamoyl complexes, with mononuclear iron compounds,... 

Cornexistin, via ring-closing diene metathesis, 11, 229 Corroles... 

Density functional theory studies arene chromium tricarbonyls, 5, 255 beryllium monocyclopentadienyls, 2, 75 chromium carbonyls, 5, 228 in computational chemistry, 1, 663 Cp-amido titanium complexes, 4, 464—465 diiron carbonyl complexes, 6, 222 manganese carbonyls, 5, 763 molybdenum hexacarbonyl, 5, 392 and multiconfiguration techniques, 1, 649 neutral, cationic, anionic chromium carbonyls, 5, 203-204 nickel rj2-alkene complexes, 8, 134—135 palladium NHC complexes, 8, 234 Deoxygenative coupling, carbonyls to olefins, 11, 40 (+)-4,5-Deoxyneodolabelline, via ring-closing diene metathesis, 11, 219... 

Dihapto 7>ligands, in copper complexes, 2, 174 Dihydride iridium complexes, preparation, 7, 396 Dihydrido clusters, with decarutheniums, 6, 1036 Dihydrobenzofuran, carbene C-H insertions, 10, 193 Dihydrobenzopyran, carbene C-H insertions, 10, 193 ring-closing diene metathesis,... 

Dirhodium tetraphosphine, for hydroformylations, 7, 252 Discodermolide, via ring-closing diene metathesis, 11, 218 Discotic mesogens mesophases, properties, 12, 202 properties, 12, 202 Diselenides... 

Ru and Os tetranuclear clusters, 6, 874 in transition metal complex electron counting, 1, 2-3 Eight-membered rings, via ring-closing diene metathesis,... 

Eleutherobin, via ring-closing diene metathesis, 11, 229 Eleven-membered rings with G-G bonds, 3, 706-707 via ring-closing diene metathesis, 11, 227 Eleven-vertex carboranes, preparation, 3, 63, 3, 97 Elimination reactions... 

Karstedt s catalyst, nickel analog, 8, 138-139 Kedarcidin, via ring-closing diene metathesis, 11, 208-209 Kendomycin, via ring-closing metathesis, 11, 239 KERD, see Kinetic energy release distribution Ketenes, niobium complexes, 5, 84 Ketenimines... 

Merrilactone A, via ring-closing diene metathesis, 11, 210 Mesitylato complex, with Pd, 8, 347 Mesitylbismuth dibromide, synthesis, 3, 916 Mesitylbismuth dichloride, synthesis, 3, 916 Mesitylcopper complex, characteristics, 2, 157... 

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