$\mathrm{CO}$, as a common waste product in industrial production, has been a focal point of research for the preparation of carbonyl compounds. A laboratory achieved the reuse of $\mathrm{CO}$ using $\mathrm{dippe}$ and $\mathrm{Ni(CO)_{4}}$ as catalysts. $\mathrm{Ni(CO)_{4}}$ and $\mathrm{dippe}$ undergo a ligand substitution reaction to form the precursor $\mathbf{A}$. Under a $\mathrm{CO}$ atmosphere, biphenylene is added, and the reaction catalyzed by $\mathrm{Ni(CO)_{4}}$ and $\mathrm{dippe}$ yields dibenzocyclopentenone. The catalytic cycle is illustrated in the following diagram:  

<MultiModal>![The diagram depicts a reaction system with a cyclic structure, involving 6 reactions. The first reaction is O#[C][Ni]([C]#O)([C]#O)[C]#O > dippe > [A], releasing one molecule of C#O; the second reaction is [A] >> [B], releasing another molecule of C#O. The subsequent four reactions form a cyclic structure in the diagram: [B] > C1=CC=C2C(=C1)C3=C2C=CC=C3 > [C], [C] >> [D], [D] > C#O > [E], [E] >> [B].C1=CC2=C(C=C1)C(=O)C3=C2C=CC=C3. Here, all instances of "[C]" represent the substance code C rather than methane. The structure of dippe is CC(C)P(CCP(C(C)C)C(C)C)C(C)C](/media/uploads/87af9806-3690-43f0-8349-99e78fc73c7d.png)</MultiModal>  

Identify all steps involving the formation of new carbon-carbon bonds in this reaction cycle.
$\mathrm{CO}$作为工业生产的常见废物，利用$\mathrm{CO}$制备羰基化合物一直是人们研究的反应热点。有实验室通过$\mathrm{dippe}$和 $\mathrm{Ni(CO)_{4}}$作为催化剂实现了$\mathrm{CO}$的再利用。 $\mathrm{Ni(CO)_{4}}$和$\mathrm{dippe}$发生配体取代反应得到反应前体$\mathbf{A}$，在$\mathrm{CO}$气氛中，加入联苯烯经$\mathrm{Ni(CO)_{4}}$和$\mathrm{dippe}$催化反应生成二苯并环戊酮。其催化循环流程如下图所示：

<MultiModal>![图中描述了具有循环结构的反应体系，包含6个反应。第一个反应为O#[C][Ni]([C]#O)([C]#O)[C]#O>dippe>[A]，脱落一分子C#O，第二个反应为[A]>>[B]，脱落一分子C#O。后4个反应在图中构成循环结构，分别为[B]>C1=CC=C2C(=C1)C3=C2C=CC=C3>[C]，[C]>>[D]，[D]>C#O>[E]，[E]>>[B].C1=CC2=C(C=C1)C(=O)C3=C2C=CC=C3。其中，以上所有的“[C]”表示物质代号C而非甲烷，dippe的结构为CC(C)P(CCP(C(C)C)C(C)C)C(C)C](/media/uploads/87af9806-3690-43f0-8349-99e78fc73c7d.png)</MultiModal>

指出该反应循环过程中，所有涉及新碳碳键形成的步骤。
Only from $\mathbf{B}$ to $\mathbf{C}$.
Only from $\mathbf{C}$ to $\mathbf{D}$.
Only from $\mathbf{D}$ to $\mathbf{E}$.
Only from $\mathbf{E}$ to $\mathbf{B}$.
From $\mathbf{B}$ to $\mathbf{C}$, and from $\mathbf{C}$ to $\mathbf{D}$.
From $\mathbf{B}$ to $\mathbf{C}$, and from $\mathbf{D}$ to $\mathbf{E}$.
From $\mathbf{B}$ to $\mathbf{C}$, and from $\mathbf{E}$ to $\mathbf{B}$.
From $\mathbf{C}$ to $\mathbf{D}$, and from $\mathbf{D}$ to $\mathbf{E}$.
From $\mathbf{C}$ to $\mathbf{D}$, and from $\mathbf{E}$ to $\mathbf{B}$.
From $\mathbf{D}$ to $\mathbf{E}$, and from $\mathbf{E}$ to $\mathbf{B}$.
From $\mathbf{B}$ to $\mathbf{C}$, from $\mathbf{C}$ to $\mathbf{D}$, and from $\mathbf{D}$ to $\mathbf{E}$.
From $\mathbf{B}$ to $\mathbf{C}$, from $\mathbf{C}$ to $\mathbf{D}$, and from $\mathbf{E}$ to $\mathbf{B}$.
From $\mathbf{B}$ to $\mathbf{C}$, from $\mathbf{D}$ to $\mathbf{E}$, and from $\mathbf{E}$ to $\mathbf{B}$.
From $\mathbf{C}$ to $\mathbf{D}$, from $\mathbf{D}$ to $\mathbf{E}$, and from $\mathbf{E}$ to $\mathbf{B}$.
From $\mathbf{B}$ to $\mathbf{C}$, from $\mathbf{C}$ to $\mathbf{D}$, from $\mathbf{D}$ to $\mathbf{E}$, and from $\mathbf{E}$ to $\mathbf{B}$.
There are no steps involving the formation of new carbon-carbon bonds in this reaction cycle.
只有$\mathbf{B}$到$\mathbf{C}$。
只有$\mathbf{C}$到$\mathbf{D}$。
只有$\mathbf{D}$到$\mathbf{E}$。
只有$\mathbf{E}$到$\mathbf{B}$。
从$\mathbf{B}$到$\mathbf{C}$，以及从$\mathbf{C}$到$\mathbf{D}$。
从$\mathbf{B}$到$\mathbf{C}$，以及从$\mathbf{D}$到$\mathbf{E}$。
从$\mathbf{B}$到$\mathbf{C}$，以及从$\mathbf{E}$到$\mathbf{B}$。
从$\mathbf{C}$到$\mathbf{D}$，以及从$\mathbf{D}$到$\mathbf{E}$。
从$\mathbf{C}$到$\mathbf{D}$，以及从$\mathbf{E}$到$\mathbf{B}$。
从$\mathbf{D}$到$\mathbf{E}$，以及从$\mathbf{E}$到$\mathbf{B}$。
从$\mathbf{B}$到$\mathbf{C}$，从$\mathbf{C}$到$\mathbf{D}$，以及从$\mathbf{D}$到$\mathbf{E}$。
从$\mathbf{B}$到$\mathbf{C}$，从$\mathbf{C}$到$\mathbf{D}$，以及从$\mathbf{E}$到$\mathbf{B}$。
从$\mathbf{B}$到$\mathbf{C}$，从$\mathbf{D}$到$\mathbf{E}$，以及从$\mathbf{E}$到$\mathbf{B}$。
从$\mathbf{C}$到$\mathbf{D}$，从$\mathbf{D}$到$\mathbf{E}$，以及从$\mathbf{E}$到$\mathbf{B}$。
从$\mathbf{B}$到$\mathbf{C}$，从$\mathbf{C}$到$\mathbf{D}$，从$\mathbf{D}$到$\mathbf{E}$，以及从$\mathbf{E}$到$\mathbf{B}$。
该反应循环中不存在涉及新碳碳键形成的步骤。
From $\mathrm{Ni(CO)_4}$ to $\mathbf{A}$, a ligand substitution reaction occurs, where the bidentate ligand $\mathrm{dippe}$ replaces two $\mathrm{CO}$ ligands, resulting in the tetrahedral complex $\mathbf{A}$ with the structure $\mathrm{(dippe)Ni(CO)_2}$.  

<Checkpoint>[The transformation from $\mathrm{Ni(CO)_4}$ to $\mathbf{A}$ is a ligand substitution reaction](1)</Checkpoint>  

<MultiModal>![CC(C)[P]1(C(C)C)[Ni]([P](C(C)C)(C(C)C)CC1)([C]#O)[C]#O, i.e., the structure of (dippe)Ni(CO)_2, tetrahedral](/media/uploads/005a11aa-1a6e-4c76-a08c-5f81f2e69874.png)</MultiModal>  

In the $\mathbf{A}$ molecule, $\mathrm{Ni}$ is 4-coordinate.  

<Checkpoint>[$\mathbf{A}$ is $\mathrm{(dippe)Ni(CO)_2}$](1)</Checkpoint>  

From $\mathbf{A}$ to $\mathbf{B}$, one carbonyl ligand dissociates, changing the geometry to trigonal planar, with $\mathbf{B}$ being $\mathrm{(dippe)Ni(CO)}$.  

<Checkpoint>[The transformation from $\mathbf{A}$ to $\mathbf{B}$ is a ligand dissociation reaction](1)</Checkpoint>  

<MultiModal>![CC(C)[P]1(C(C)C)[Ni]([P](C(C)C)(C(C)C)CC1)[C]#O, i.e., the structure of (dippe)Ni(CO), trigonal planar](/media/uploads/88eb7859-c0d0-4c15-85d5-0bded74e39e7.png)</MultiModal>  

In the $\mathbf{B}$ molecule, $\mathrm{Ni}$ is 3-coordinate.  

<Checkpoint>[$\mathbf{B}$ is $\mathrm{(dippe)Ni(CO)}$](1)</Checkpoint>  

$\mathbf{B}$ undergoes an oxidative addition reaction with the organic molecule C1=CC=C2C(=C1)C3=C2C=CC=C3 to yield $\mathbf{C}$. In this process, one $\mathrm{C-C}$ bond is broken, and two new $\mathrm{C-Ni}$ bonds are formed, resulting in a five-membered ring. The structure of $\mathbf{C}$ is:  

<MultiModal>![CC(C)[P]1(C(C)C)[Ni]2([P](C(C)C)(C(C)C)CC1)(C3=CC=CC=C3C4=CC=CC=C42)[C]#O, where the complex center consists of one Ni atom, coordinated by one monodentate CO, one bidentate dippe, and one bidentate C1=CC=C[C]=C1C2=[C]C=CC=C2. The geometry is trigonal bipyramidal, with the carbon of C#O and one phosphorus atom of dippe in axial positions, while the remaining coordination atoms lie in the equatorial plane.](/media/uploads/625877b8-aa78-4210-b59d-02cee543bc3c.png)</MultiModal>  

<Checkpoint>[The transformation from $\mathbf{B}$ to $\mathbf{C}$ is an oxidative addition reaction](1)</Checkpoint>  

In the $\mathbf{C}$ molecule, $\mathrm{Ni}$ is 5-coordinate with a trigonal bipyramidal geometry.  

From $\mathbf{C}$ to $\mathbf{D}$, a migratory insertion reaction occurs intramolecularly, breaking one $\mathrm{C-Ni}$ bond and forming one $\mathrm{C-C}$ bond.  

<Checkpoint>[The transformation from $\mathbf{C}$ to $\mathbf{D}$ is a migratory insertion reaction](1)</Checkpoint>  

The structure of $\mathbf{D}$ is:  

<MultiModal>![CC(C)[P]1(C(C)C)[Ni]2(C3=CC=CC=C3C4=CC=CC=C4C2=O)[P](C(C)C)(C(C)C)CC1, where the complex center consists of one Ni atom, coordinated by one bidentate dippe and one bidentate [C](=O)C1=C(C=CC=C1)C2=[C]C=CC=C2. The geometry is square planar.](/media/uploads/f8636b5c-a46b-4576-a3c8-6dfb209af3bb.png)</MultiModal>  

In the $\mathbf{D}$ molecule, $\mathrm{Ni}$ is 4-coordinate.  

From $\mathbf{C}$ to $\mathbf{D}$, one new carbon-carbon bond is formed.  

<Checkpoint>[From $\mathbf{C}$ to $\mathbf{D}$, one new C-C bond is formed](1)</Checkpoint>  

From $\mathbf{D}$ to $\mathbf{E}$, one molecule of $\mathrm{CO}$ is added, forming one new $\mathrm{C-Ni}$ bond while the structures of the other ligands remain unchanged. The structure of $\mathbf{E}$ is:  

<MultiModal>![CC(C)[P]1(C(C)C)[Ni]2(C3=CC=CC=C3C4=CC=CC=C4C2=O)([C]#O)[P](C(C)C)(C(C)C)CC1, where the complex center consists of one Ni atom, coordinated by one monodentate C#O, one bidentate dippe, and one bidentate [C](=O)C1=C(C=CC=C1)C2=[C]C=CC=C2. The geometry is trigonal bipyramidal, with the carbon of C#O and the acyl carbon of [C](=O)C1=C(C=CC=C1)C2=[C]C=CC=C2 in axial positions, while the remaining coordination atoms lie in the equatorial plane.](/media/uploads/5193b191-2259-475d-89a2-2f0dee6d216f.png)</MultiModal>  

In the $\mathbf{E}$ molecule, $\mathrm{Ni}$ is 5-coordinate.  

<Checkpoint>[The transformation from $\mathbf{D}$ to $\mathbf{E}$ is a ligand association reaction](1)</Checkpoint>  

From $\mathbf{E}$ to $\mathbf{B}$, a reductive elimination reaction occurs, releasing one molecule of C1=CC2=C(C=C1)C(=O)C3=C2C=CC=C3, and $\mathrm{Ni}$ reverts from 5-coordinate to 3-coordinate.  

<Checkpoint>[The transformation from $\mathbf{E}$ to $\mathbf{B}$ is a reductive elimination reaction](1)</Checkpoint>  

In this process, a new carbon-carbon bond is formed in the released organic molecule C1=CC2=C(C=C1)C(=O)C3=C2C=CC=C3.  

<Checkpoint>[From $\mathbf{E}$ to $\mathbf{B}$, a new C-C bond is formed in the released organic molecule](1)</Checkpoint>  

In summary, during the catalytic cycle described above, new carbon-carbon bond formation occurs in the transformations from $\mathbf{C}$ to $\mathbf{D}$ and from $\mathbf{E}$ to $\mathbf{B}$.
从$\mathrm{Ni(CO)_4}$到$\mathbf{A}$，发生配体取代反应，双齿配体$\mathrm{dippe}$取代两个$\mathrm{CO}$，得到具有四面体构型的配合物$\mathbf{A}$，其结构为$\mathrm{(dippe)Ni(CO)_2}$。

<Checkpoint>[$\mathrm{Ni(CO)_4}$到$\mathbf{A}$为配体取代反应](1)</Checkpoint>

<MultiModal>![CC(C)[P]1(C(C)C)[Ni]([P](C(C)C)(C(C)C)CC1)([C]#O)[C]#O，即(dippe)Ni(CO)_2的结构，四面体](/media/uploads/005a11aa-1a6e-4c76-a08c-5f81f2e69874.png)</MultiModal>

在$\mathbf{A}$分子中，$\mathrm{Ni}$为4配位。

<Checkpoint>[$\mathbf{A}$为$\mathrm{(dippe)Ni(CO)_2}$](1)</Checkpoint>

从$\mathbf{A}$到$\mathbf{B}$，离去一个羰基，构型变为平面三角形，$\mathbf{B}$为$\mathrm{(dippe)Ni(CO)}$。

<Checkpoint>[$\mathbf{A}$到$\mathbf{B}$为配体解离反应](1)</Checkpoint>

<MultiModal>![CC(C)[P]1(C(C)C)[Ni]([P](C(C)C)(C(C)C)CC1)[C]#O，即(dippe)Ni(CO)的结构，平面三角形](/media/uploads/88eb7859-c0d0-4c15-85d5-0bded74e39e7.png)</MultiModal>

在$\mathbf{B}$分子中，$\mathrm{Ni}$为3配位。

<Checkpoint>[$\mathbf{B}$为$\mathrm{(dippe)Ni(CO)}$](1)</Checkpoint>

$\mathbf{B}$与有机分子C1=CC=C2C(=C1)C3=C2C=CC=C3发生氧化加成反应得到$\mathbf{C}$，此过程中断裂1根$\mathrm{C-C}$键，新生成2根$\mathrm{C-Ni}$键，得到五元环。$\mathbf{C}$的结构为：

<MultiModal>![CC(C)[P]1(C(C)C)[Ni]2([P](C(C)C)(C(C)C)CC1)(C3=CC=CC=C3C4=CC=CC=C42)[C]#O，配合物中心为1个Ni，配体为1个单齿CO，1个双齿dippe，1个双齿C1=CC=C[C]=C1C2=[C]C=CC=C2，三角双锥构型，C#O中的碳以及dippe的1个磷原子位于轴向，其余配位原子位于赤道面](/media/uploads/625877b8-aa78-4210-b59d-02cee543bc3c.png)</MultiModal>

<Checkpoint>[$\mathbf{B}$到$\mathbf{C}$为氧化加成反应](1)</Checkpoint>

在$\mathbf{C}$的分子中，$\mathrm{Ni}$为5配位，具有三角双锥构型。

从$\mathbf{C}$到$\mathbf{D}$，分子内发生迁移插入反应，断裂1根$\mathrm{C-Ni}$键，生成1根$\mathrm{C-C}$键。

<Checkpoint>[$\mathbf{C}$到$\mathbf{D}$为迁移插入反应](1)</Checkpoint>

$\mathbf{D}$的结构为：

<MultiModal>![CC(C)[P]1(C(C)C)[Ni]2(C3=CC=CC=C3C4=CC=CC=C4C2=O)[P](C(C)C)(C(C)C)CC1，配合物中心为1个Ni，配体为1个双齿dippe，1个双齿[C](=O)C1=C(C=CC=C1)C2=[C]C=CC=C2，平面四方构型](/media/uploads/f8636b5c-a46b-4576-a3c8-6dfb209af3bb.png)</MultiModal>

在$\mathbf{D}$分子中，$\mathrm{Ni}$为4配位。

从$\mathbf{C}$到$\mathbf{D}$，生成了1根新的碳碳键。

<Checkpoint>[从$\mathbf{C}$到$\mathbf{D}$，生成1根新碳碳键](1)</Checkpoint>

从$\mathbf{D}$到$\mathbf{E}$，加入了一分子$\mathrm{CO}$，新生成1根$\mathrm{C-Ni}$键，其余配体的结构不变。$\mathbf{E}$的结构为：

<MultiModal>![CC(C)[P]1(C(C)C)[Ni]2(C3=CC=CC=C3C4=CC=CC=C4C2=O)([C]#O)[P](C(C)C)(C(C)C)CC1，配合物中心为1个Ni，配体为1个单齿C#O，1个双齿dippe，1个双齿[C](=O)C1=C(C=CC=C1)C2=[C]C=CC=C2，三角双锥构型，C#O中的碳以及[C](=O)C1=C(C=CC=C1)C2=[C]C=CC=C2中的酰基碳位于轴向，其余配位原子位于赤道面](/media/uploads/5193b191-2259-475d-89a2-2f0dee6d216f.png)</MultiModal>

在$\mathbf{E}$分子中，$\mathrm{Ni}$为5配位。

<Checkpoint>[从$\mathbf{D}$到$\mathbf{E}$为配体结合反应](1)</Checkpoint>

从$\mathbf{E}$到$\mathbf{B}$，发生还原消除反应，离去1分子的C1=CC2=C(C=C1)C(=O)C3=C2C=CC=C3，$\mathrm{Ni}$从5配位变回3配位。

<Checkpoint>[$\mathbf{E}$到$\mathbf{B}$为还原消除反应](1)</Checkpoint>

该过程中，在C1=CC2=C(C=C1)C(=O)C3=C2C=CC=C3分子中形成了1根新的碳碳键。

<Checkpoint>[从$\mathbf{E}$到$\mathbf{B}$，离去的有机分子中形成新的碳碳键](1)</Checkpoint>

综上，在上述催化循环过程中，涉及新碳碳键形成的过程有$\mathbf{C}$到$\mathbf{D}$，以及$\mathbf{E}$到$\mathbf{B}$。