Representative Procedures

The Leimgruber-Batcho synthesis is a two-step method which provides indoles that arc substituted only in the benzene ring. The method was initially disclosed in a patent[l] and a representative procedure is available in Organic Syntheses[2]. A review of the reaction is available[3]. The reaction involves... 

Because Pd(II) salts, like Hgtll) salts, can effect electrophilic metallation of the indole ring at C3, it is also possible to carry out vinylation on indoles without 3-substituents. These reactions usually require the use of an equiv. of the Pd(ll) salt and also a Cu(If) or Ag(I) salt to effect reoxidation of the Pd. As in the standard Heck conditions, an EW substitution on the indole nitrogen is usually necessary. Entry 8 of Table 11.3 is an interesting example. The oxidative vinylation was achieved in 87% yield by using one equiv. of PdfOAcfj and one equiv. of chloranil as a co-oxidant. This example is also noteworthy in that the 4-broino substituent was unreactive under these conditions. Part B of Table 11.3 lists some other representative procedures. 

Representative procedure for BujSnH/Cul/LiCI conjugate reduction [20 ... 

Representative procedure for conjugate reduction-aldol 3-CC 2- Hydroxy-[l-[tolue sulfonyl)- H-indol-3-yl]-methyl -4,4-dimethylcyclohexanone [35]... 

Bis(3,5-di-tert-butyl-4-hydroxyphenyl) acetone mercaptole, melting at 125°C to 126°C is prepared by employing 2,6-di-tert-butyl-4-mercaptophenol and acetone as starting materials. In one representative procedure, the 2,6-di-tert-butyl-4-mercaptophenol (47.5 g, 0.2 mol) is dissolved in methanol (50 ml) heated at a temperature of 50°C. A catalytic amount of concentrated hydrochloric acid (1 ml) is added, followed by acetone (5S g,0.1 mol). The temperature of the mixture rises to about 60°C, and is maintained at about 60°C to 65°C for 1.5 hours. The mixture is cooled, diluted with water and about 10 ml of aqueous sodium bicarbonate and extracted with ether. The ether extract is evaporated, and the product is obtained as a residue, which is recrystallized from ethanol and then from isopropanol to obtain the bis(3,5-di-tert-butyl-4-hydroxyphenyl) acetone mercaptole as a crystalline solid melting at about 125°Cto 126°C. 

In another representative procedure about 2.3 mols of 2,6-di-tert-butyl-4-mercaptophenol is dissolved in about 1,700 ml of methanol under a nitrogen atmosphere about 100 ml of concentrated hydrochloric acid and 1B0 ml of acetone are added, and the mixture is stirred and maintainedat a temperature of about 35°C to 50°C, for 1.5 hours. The mixture is then cooled to room temperature and filtered, and the bis(3,5-di-tert-butyl-4-hydroxyphenyl) acetone mercaptole product is collected as a colorless crystalline solid filter cake. The product is washed with water and aqueous sodium bicarbonate and purified by recrystallization from ethanol. 

Representative procedure for the synthesis of (Z)-a-selenenylvinylstannanes [34] A mixture of Cp2Zr(H)Cl (1.1 mmol) and (3-methoxy-l-propynyl)tributylstannane (1.0 mmol) in THF (5 mL) was stirred at room temperature for 20 min. A solution of PhSeBr (1.0 mmol) in THF (4 mL) (prepared in situ) was then injected into the resulting solution and the mixture was stirred at room temperature for 30 min. It was then diluted with light petroleum and stirred for a further 5 min., after which the supernatant was filtered through a short plug of silica gel. After evaporation of the solvent from the filtrate, the residue was purified by preparative TLC on silica gel to yield (lZ)-tributyl-[3-methoxy-l-(phenylse-leno) -1 -propenyl] stannane (60 %). 

Representative procedure forthecouplingofan alkenyliodonium tosylate with a Gilman cuprate ( )-(2-bromoprop-1 -enyl)benzene [64] To a stirred suspension of Cp2Zr(H)Cl (0.360 g, 1.4 mmol) in THF (6 mL) was added phenyl(phenylethynyl)iodonium tosylate (0.476 g,... 

We will describe representative procedures for the epoxidation of a disub-stituted aromatic allylic alcohol (A), a trisubstituted aromatic allylic alcohol (B) and a disubstituted aliphatic allylic alcohol (C). 

Representative Experimental Procedures 128 Representative Procedure for Preparation of Cl-Hemiacetal Donors Through a Peracylation-Selective Anomeric Deacylation Sequence 128... 

Representative Procedure for Bronsted Add Promoted Glycosylation with Cl-Hemiacetal Donors Using Methoxyacetic Add 128 Representative Procedure for Lewis Acid Promoted Glycosylation with Cl-Hemiacetal Donors Using Sn(OTf)2 and LiC104 129... 

Representative Procedure for Silicon Promoted Glycosylation with Cl-Hemiacetal Donors Using Me3SiBr and CoBr2 129 Representative Procedure for Mitsunobu-Type Glycosylation with Cl-Hemiacetal Donors and Phenol Glycosyl Acceptors 129 Representative Procedure for Appel-Type Glycosylation with Cl-Hemiacetal Donors 129... 

Representative Procedure for Nosyl Chloride Promoted Glycosylation with Cl-Hemiacetal Donors 130... 

Representative Procedure for Mitsunobu-Type Glycosylation with Cl-Hemiacetal Donors and Phenol Glycosyl Acceptors [90]... 

Representative Procedure for Carbonyl Promoted Clycosylation with Cl-Hemiacetal Donors Using Trichloroacetic Anhydride [152]... 

Representative Procedure for Lewis Acid Promoted Clycosylation with Glycosyl Acetate Donors Using SnCI4 [198]... 

Representative Procedure for TMS Triflate Promoted Clycosylation with Glycosyl N-Tosyl Carbamate Donors [343]... 

Representative Procedure for Trityl Salt Promoted Clycosylation with Glycosyl Phenyl Carbonate Donors [360]... 

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