Cyano group has strong polarity and electron absorption, so it can go deep into the target protein to form hydrogen bonds with key amino acid residues in the active site. At the same time, cyano group is the bioelectronic isosteric body of carbonyl, halogen and other functional groups, which can enhance the interaction between small drug molecules and target proteins, so it is widely used in the structural modification of medicine and pesticides [1]. The representative cyano containing medical drugs include saxagliptin (Figure 1), verapamil, febuxostat, etc; Agricultural drugs include bromofenitrile, fipronil, fipronil and so on. In addition, cyano compounds also have important application value in the fields of fragrance, functional materials and so on. For example, Citronitrile is an international new nitrile fragrance, and 4-bromo-2,6-difluorobenzonitrile is an important raw material for preparing liquid crystal materials. It can be seen that cyano compounds are widely used in various fields due to their unique properties [2].

Cyano group has strong polarity and electron absorption, so it can go deep into the target protein to form hydrogen bonds with key amino acid residues in the active site. At the same time, cyano group is the bioelectronic isosteric body of carbonyl, halogen and other functional groups, which can enhance the interaction between small drug molecules and target proteins, so it is widely used in the structural modification of medicine and pesticides [1]. The representative cyano containing medical drugs include saxagliptin (Figure 1), verapamil, febuxostat, etc; Agricultural drugs include bromofenitrile, fipronil, fipronil and so on. In addition, cyano compounds also have important application value in the fields of fragrance, functional materials and so on. For example, Citronitrile is an international new nitrile fragrance, and 4-bromo-2,6-difluorobenzonitrile is an important raw material for preparing liquid crystal materials. It can be seen that cyano compounds are widely used in various fields due to their unique properties [2].

2.2 electrophilic cyanidation reaction of enol boride

Kensuke Kiyokawa’s team [4] used cyanide reagents n-cyano-n-phenyl-p-toluenesulfonamide (NCTS) and p-toluenesulfonyl cyanide (tscn) to achieve high-efficiency electrophilic cyanidation of enol boron compounds (Figure 3). Through this new scheme, various β- Acetonitrile, and has a wide range of substrates.

2.3 organic catalytic stereoselective silico cyanide reaction of ketones

Recently, Benjamin list team [5] reported in the journal Nature the enantiomeric differentiation of 2-butanone (Figure 4a) and the asymmetric cyanide reaction of 2-butanone with enzymes, organic catalysts and transition metal catalysts, using HCN or tmscn as cyanide reagent (Figure 4b). With tmscn as the cyanide reagent, 2-butanone and a wide range of other ketones were subjected to highly enantioselective silyl cyanide reactions under the catalytic conditions of idpi (Figure 4C).

Figure 4 A, enantiomeric differentiation of 2-butanone. b. Asymmetric cyanidation of 2-butanone with enzymes, organic catalysts and transition metal catalysts.

c. Idpi catalyzes the highly enantioselective silyl cyanide reaction of 2-butanone and a wide range of other ketones.

2.4 reductive cyanidation of aldehydes

In the synthesis of natural products, the green tosmic is used as a cyanide reagent to easily convert sterically hindered aldehydes into nitriles. This method is further used to introduce an additional carbon atom into aldehydes and ketones. This method has constructive significance in the Enantiospecific total synthesis of jiadifenolide and is a key step in the synthesis of natural products, such as the synthesis of natural products such as clerodane, caribenol A and caribenol B [6] (Figure 5).

2.5 electrochemical cyanide reaction of organic amine

As a green synthesis technology, organic electrochemical synthesis has been widely used in various fields of organic synthesis. In recent years, more and more researchers have paid attention to it. PrashanthW. Menezes team [7] recently reported that aromatic amine or aliphatic amine can be directly oxidized to corresponding cyano compounds in 1m KOH solution (without adding cyanide reagent) with a constant potential of 1.49vrhe using cheap Ni2Si catalyst, with high yield (Figure 6).

03 summary

Cyanidation is a very important organic synthesis reaction. Starting from the idea of green chemistry, environmental friendly cyanide reagents are used to replace traditional toxic and harmful cyanide reagents, and new methods such as solvent-free, non catalytic and microwave irradiation are used to further expand the scope and depth of research, so as to generate huge economic, social and environmental benefits in industrial production [8]. With the continuous progress of scientific research, cyanide reaction will develop towards high yield, economy and green chemistry.