Preparation of 1,2-diMagnesiummethylbenzene

The  1,2-dimagnesiummethylbenzene showing below is a useful reagent for metal ligand preparation.
This di-grignard reagent  can be made in high yield from corresponding dichloride compound.

1,2-Dibromomethylbenzene can't be used because it can cause problem.

steps:
1. activate Mg using 1,2-dibromoethane.
2. in diluted solution, slowly add dichloride into Mg in THF. control temperature at rt.
3. allow 8 hr stirring at rt.

yield is over 95% in reports.

Another approach to sordaricin

this strategy is based on a 3+2 cycloaddition.

an indole synthesis plan from nitrile

the plan is like this:

 

 it is really plausible to me. 

the additional six membered ring is required because without it, nitirle ylide will be formed instead of  the azirine. 

ps: sorry, the diazo compound is missing in the drawing.

preparation of thermodynamic silyl enol ethers

Tetrahedron Letters,Vol.24,No.l3,pp 1345-1348,1983

There now exist a variety of mild and very selective procedures for the kinetic
deprotonation of unsymmetrical ketones employing alkali metal dialkylamides. The "kinetic"
enolates produced in this way may be efficiently trapped by trimethylsilyl chloride to
regiospecifically provide the less substituted trimethylsilyl enol ethers.1 Despite the
recent introduction of several new methods, there are still no procedures available which
allow direct3 regiospecific preparation of the more substituted "thermodynamic" enolates or
trimethylsilyl enol ethers.

 

this paper described a way using MeMgBr/diisopropylamine to generate the thermodynamic enolate at rt, which worked out as described.(HMPA is necessary, without it, no rxn at all).

a mild alternative nitrene generation method for C-H amination

current method involve hypervalence iodine to oxidize the carbamate or sulfonamates to the imidoiodo species followed by metal incorperation to do following C-H aminations.
One problem limiting the rxn scope and catalyst preformance is the the high-oxidative potencial of the hypervalenc iodine compund such as pida, pifa.

here I propose a new oxidant which is a imidoiodo compound with a bulky blocking group attached to the imine. It is a milder oxidant than the pida/pifa and with a certain sized bulky group, the oxidant might be able to exchange its iodo with  a carbamte but not able to react with the metal like rhodium.
Such a setup can increase the catalyst scope and performance and also milder the rxn condition.

Isomerization of conjugated double bond

Recently found an interesting reaction which isomerized the conjugated double bond by the following sequence:
1. ketalize the ketone by acid/ethylene glycol. during which rxn the double bond isomerized to the more substituted position.
2. remove the ketal by oxalic acid which is efficient and mild enough to keep the double bond from isomerization to the more stable conjugated position.

very cool transformations, which demonstrated the author's deep understanding of those reagents and the beauty of organic transformations.
the paper was published about 30-40 years ago in jacs.

Oxidative cleavage of α-hydroxyketones

Tetrahedron Letters 50 (2009) 5399–5402
 "
The oxidative cleavage of vicinal diols, a-hydroxyketones, and related functionalities is a common synthetic procedure and various reagents are available to perform this reaction, such as sodium bismuthate,1 iodo triacetate,2 manganic pyrophosphate,3 KHSO5,4 calcium hypochlorite,5 basic hydrogen peroxide,6 methylrhenium trioxide,7 Bi/O2,8 sodium percarbonate,9 and vanadium-based HPA and dioxygen.10 However, the most versatile reagents for this purpose are sodium metaperiodate,11 and lead tetraacetate.12–14
Usually sodium metaperiodate is used in aqueous solutions, because the effectiveness of this oxidant in organic solvents is very limited due to its insolubility.15 Lead tetraacetate has been used in non-aqueous media to accomplish the same types of reactions effected by periodates with water-soluble compounds.15 On the
other hand, this reagent is difficult to store and handle, non-environmentally friendly and, being more reactive, can afford undesired oxidation byproducts.
Aiming to expand the versatility of sodium metaperiodate as an oxidating reagent in organic media, and to overcome the solubilityissues, variations of a silica gel-supported sodium metaperiodate reagent have been disclosed, to promote oxidative cleavage of 1,2 diols, and oxidation of hydroquinones and sulfur-containing compounds.16–18 Usually the sodium periodate is adsorbed on silica gel, and stirred with the starting material in dichloromethane, ether, or benzene.
"
One of the conditions described in the reference paper (NaIO4/SiO2/toluene) was applied to a mixture of alpha-hydroxyketone and TMS protected alpha-hydroxyketone shown below.
Surprisingly, only alpha-hydroxyketone was cleaved. The TMS protected alpha-hydroxyketone survived.
compared with HIO4 in Et2O, this condition (NaIO4/SiO2/toluene) is more neutral.